EPA-450/4-74-004
August 1974
(OAQPS No. 1.2-023)
GUIDELINES FOR AIR QUALITY
MAINTENANCE PLANNING AND ANALYSIS
VOLUME 4:
LAND USE AND TRANSPORTATION
CONSIDERATIONS
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EPA-450/4-74-004
(OAQPS No. 1.2-023)
GUIDELINES FOR AIR QUALITY
MAINTENANCE PLANNING AND ANALYSIS
VOLUME 4:
LAND USE AND TRANSPORTATION
CONSIDERATIONS
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Waste Management
Office of Air Quality Planning and Standards
Research Triangle Park, N. C. 27711
August 1974
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The guideline series of reports is being issued by the Office of Air
Quality Planning and Standards (OAQPS) to provide information to state
and local air pollution control agencies;'for example, to provide guid-
ance on the acquisition and processing of air quality data and on the
planning and analysis requisite for the maintenance of air quality
Reports published in this series will be available - as supplies permit
from the Air Pollution Technical Information Center, Research Trianqle
Park, North Carolina 27711; or, for a nominal fee, from the National
Technical Information Service, 5285 Port'Royal Road, Sorinqfipld
Virginia 22151. c s - »
This report was furnished to the Environmental Protection Aqencv bv
Alan M Voorhees and Associates, Inc., McLean, Va., in fulfillment of
Task Order No. 1, Contract Number 68-02-1388. The contents are repro-
duced herein as received from the contractor. Prior to final prepara-
tion the report underwent extensive review and editing by the Environ-
mental Protection Agency and other concerned organizations. The contents
reflect current Agency thinking and will form the basis for promulgation
of official policy in Requirements for Preparation, Adoption, and Sub-
tmttai of Implementation Plans (40 CFR Part 51).
Publication No. EPA-450/4-74-004
(OAQPS Guideline No. 1.2-023)
n
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FOREWORD
a seres comprising Guidelines for Air Quality
The intent of the series is to provide State
This document is the fourth n
Maintenance Planning and Analysis.
and local agencies with information and guidance for the preparation of Air Quality
Maintenance Plans required under 40 CFR 51. The volumes in this series are:
Volume 1: Designation of Air Quality Maintenance Areas
Volume 2: Plan Preparation
Volume 3: Control Strategies
Volume 4: Land Use and Transportation Considerations
Volume 5: Case Studies in Plan Development
Volume 6: Overview of Air Quality Maintenance Area Analysis
Volume 7: Projecting County Emissions
Volume 8: Computer-Assisted Area Source Emissions Gridding Procedure
Volume 9: Evaluating Indirect Sources
Volume 10: Reviewing New Stationary Sources
Volume 11: Air Quality Monitoring and Data Analysis
Volume 12: Applying Atmospheric Simulation Models to Air Quality Maintenance
Areas
Additional volumes may be issued.
All references to 40 CFR Part 51 in this document are to the regulations
as amended through July 1974.
11 i
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TABLE OF CONTENTS
Chapter E§S1
I INTRODUCTION 1
A. Requirement for Air Quality Maintenance Plan
Preparation and Analysis 1
B. Report Organization 1
II OVERVIEW OF LAND USE AND TRANSPORTATION PLANNING . . 3
A. The Comprehensive Plan 3
1. The Land Use Plan 8
2. The Utility of the Land Use Plan 17
3. The Influence of Land Use Planning on
Development 21
4. The Potential for Change 29
B. The 3-C Process 30
1. Current Practice 30
2. Legislative Requirements 32
3. Agencies and Groups Involved in the
3-C Process 36
4. General Description of the 3-C Process . . 37
5. Data Sets and Formats 50
III AIR QUALITY MAINTENANCE AND COMPREHENSIVE PLANNING . 53
A. General Approach for Considering Air Quality
Maintenance in the Comprehensive Planning
Process 53
B. A Process for Evaluating the Impacts of Land
Use and Air Quality Plans or Policies .... 53
C. Information and Organization to Relate Land
Use to Emissions and Air Quality
D. Analytical Techniques Required to Relate Land
Use and Transportation Plans to Air Quality . 63
References 65
Appendices
A Review of the State-of-the-Art for Quantifying the
Relationship of Land Use and Transportation Plans to
Air Quality A-l
B Review of Selected Studies Relating Land Use and
Transportation to Air Quality B-l
C Annotated Bibliography of Activity Allocation
Procedures C-l
D Bibliographic Data Sheet D-l
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LIST OF FIGURES
Page
Generalized Activities of the 3-C Planning Process . 33
The Air Quality Impact-Land Use Planning Process . . 55
III-2 Information Access Requirements of a Process to
Relate Land Use and Transportation Plans to Air
Quality 59
LIST OF TABLES
Tables
III-l Summary of Estimated 1990 Annual Emission Rates
for Hackensack Meadowlands Land Use Categories ... 60
APPENDIX TABLES
A-l State-of-the-Art Summary Emissions Projections
Techniques A-7
A-2 State-of-the-Art Summary Air Quality Projection
Techniques A-8
VI
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CHAPTER I
INTRODUCTION
A. REQUIREMENT FOR AIR QUALITY MAINTENANCE PLAN PREPARATION AND ANALYSIS
The 1970 Clean Air Act (as amended) has mandated all states to iden-
tify areas that are in violation of the National Ambient Air Quality
Standards (NAAQS). These standards, as set forth by the U.S. Environmental
Protection Agency (EPA), prescribe the control of sulfur oxides (SOj,
particulate matter (TSP), carbon monoxide (CO), hydrocarbons (HC), nitrogen
dioxide (N02), and photochemical oxidants. This is to be accomplished by
the State Implementation Plan (SIP). In addition, all states, pursuant to
40 CFR 51.12(c), are required to identify areas that have the potential to
be in violation of any NAAQS over the 10-year period, 1975-1985. These
areas are called Air Quality Maintenance Areas (AQMA), identified by the
states, and reviewed by the EPA Administrator, who issues an official list
of designated AQMAs.
For these areas, the states must submit plans to prevent any national
standard from being exceeded over the 10-year period. For each pollutant
in each of the AQMAs for which analysis indicates a potential problem,
tailored maintenance strategies must be submitted. These plans, Air Qua-
lity Maintenance Plans (AQMP), must be prepared, adopted, and submitted in
compliance with guidelines issued by EPA. Considerations such as terrain,
meteorological conditions, transportation and land use planning, and eco-
nomic considerations can be incorporated into the AQMP.
B. REPORT ORGANIZATION
Chapter II of this report presents an overview of land use and trans-
portation planning. The comprehensive plan and the 3-C process are des-
cribed. This discussion is intended to provide air quality planners with a
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brief review of the comprehensive planning process and its implications for
air quality maintenance planning.
Chapter III presents a general approach for considering air quality
maintenance in the comprehensive planning process. A procedure for
analyzing the impact of land use and transportation plans or policies is
described. This analytical procedure would provide a basis for review
and evaluation. The analytical procedure may require the development
of techniques to relate land use to air quality. These analytical re-
quirements are discussed.
Appendix A is a review of the state-of-the-art in quantifying the
relationship between land use and air quality.
Appendix B summarizes selected studies that were reviewed in the
preparation of the state-of-the-art review.
Appendix C is an annotated bibliography of activity allocation pro-
cedures that may be useful in the development of analysis procedures for
incorporating air quality maintenance intc comprehensive planning.
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CHAPTER II
OVERVIEW OF LAND USE AND TRANSPORTATION PLANNING
A. THE COMPREHENSIVE PLAN
The land use plan, as a document, exists within the broader frame-
work of the comprehensive plan (sometimes called the master plan). "It
(the comprehensive plan) indicates in a general way how the citizenry of
a jurisdiction, represented by its leaders, wants its community to develop
physically over the next 20 to 30 years."* In this context, the word
"comprehensive" generally means that the developed plan encompasses all
geographic parts of the community and all functional elements that bear
on physical development. In the past, the emphasis on physical develop-
ment has often excluded considerations of the environment, resulting in
the generation of harmful impacts. A redefinition of the comprehensive
planning process, which seeks a more balanced approach to the considera-
tion of economic, social, and environmental variables, is a recent factor
in the planning process. At the present time, several agencies, includ-
ing EPA and the Department of Housing and Urban Development (HUD), are
developing procedures to reflect this expanded concept. These are in the
initial stages, and no material is available for reference.
The comprehensive plan as a policy statement presents development
proposals for both public and private land within the planning area. The
comprehensive plan as a schematic map presents the spatial allocations
and location of various land use categories plus transportation and
community facilities. Although there is no rigid format for the plan,
the elements included have tended to become standardized. The following
is a generalized sequence of the information included:
* Alan Black, "The Comprehensive Plan," Principles and Practice of Urban
Planning, edited by William I. Goodman and Eric C. Freund (Washington,
D.C.: ICMA, 1968), p. 349.
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t Background information - This phase of the planning process is
directed toward data collection and data processing. Key con-
siderations are studies of the urban economy, employment,
population, activity systems, and urban land. Such studies are
a prerequisite to the task of determining future land use
requirements and the subsequent land use planning proposals.
Planning studies also deal with the physical opportunities and
constraints imposed by flood plains, soils and geologic condi-
tions, topography, and climate. This element typically includes
land use objectives and goals that provide a guide to the way
in which development should proceed to fulfill the needs of
residents, firms, and institutions of the area.
t Functional plans - This series of specific land use and faci-
lities plans forms the body of the document. The plans gene-
rally include sections on residential, commercial, and indus-
trial areas; recreational and community facilities; public
utilities; and transportation.
• The comprehensive plan - The final product is a synthesis of
the functional plans, providing an explanation of how various
major functions are tied together by thoroughfares and developed
in balanced relationship to one another. An important element
of the comprehensive plan is the means by which it is to be
implemented. A program to implement the plan is concerned with
such regulatory measures as zoning, subdivision control, and
housing and building codes. A public works program also may be
included.
In spite of the fact that the elements included in the plan are
fairly standard, there is a wide variation in the level of detail. This
variation is due in large part to the strong motivation by the Federal
government for the development of comprehensive plans at various juris-
dictional levels, from local to regional and state.
Although comprehensive planning has existed as a concept for over
50 years, it only began to move to the forefront of local planning agency
concerns after World War II. The impetus was the Federal government's
increasing tendency to make financial assistance conditional upon con-
formance to a local comprehensive plan. This requirement has been supple-
mented by Federal funds to be used for the purpose of preparing these
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plans. Two of the chief sources of this type of Federal planning grant
have been Section 701 of the Housing Act of 1954, as amended, (the "701
Program") and the transportation planning grants under the Federal-aid
Highway Act of 1962 (the 3-C Process). The 701 planning grants were made
under this program to established state or local planning units that
applied for them. Under these grants, the primary concern was with
housing, transportation, or general land use. However, whatever the
primary focus, planning was generally integrated to some extent into the
total urban scene. In spite of these programs, not every area has a
comprehensive plan or the more basic land use plan.
A basic component of the comprehensive plan is a document, or series
of documents, known collectively as the land use plan. This plan is
primarily concerned with the geographic allocation and amount of land
development required for the various space-using functions of urban and
suburban 1ife—industry, business, housing, recreation, education, and
the religious and cultural activities of the people. Therefore, the land
use plan has a great influence on the other functional areas included in
the comprehensive plan, such as transportation, public facilities, and
public utilities. For this reason, this part of the comprehensive plan
provides a direct link between planning and environmental quality.
Some planning agencies, because of legislative definition or common
usage, refer to the land use plan as that portion of the comprehensive
plan devoted to private uses of land—industrial, commercial, and resi-
dential. In other areas, both public (community facilities) and private
uses are considered to be a part of the land use plan. The land use plan
should not be confused with the zoning map or the zoning ordinance. The
land use plan is not legally binding; hence, it is essential that the
necessary legislation be prepared, adopted, and enforced to transform the
general concepts into patterns that have legal substance.
Zoning is one of the several legal devices for implementing the
proposals for land development set forth in the plan. The zoning map
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is a part of the zoning ordinance and is generally conceived as a scheme
of districting an area for purposes such as land use regulation, popula-
tion density, lot coverage, bulk of structures, and parking requirements.
Both the zoning ordinance and the zoning map may be more detailed than
the land use plan.
The process for developing a land use plan is not fixed; therefore,
the procedure described in this section is generalized. The format and
procedures presented here have been adapted from the work of F. Stuart
Chapin., which presents a more detailed discussion of these topics.*
It should be stressed that the analytical procedures presented in this
section do not represent a definitive listing; rather, they represent the
approaches most commonly used by planning agencies at different levels.
The traditional approach to land use planning begins with a pro-
jection of future economic growth in the area. This projection is based
on trends in both the national and the regional economy. Given the
projection, in terms of the amount and type of economic activity trans-
lated into employment levels, future population is projected. Projec-
tions of economic activity and population are then translated in turn
into projections for future land demand for industrial, commercial,
residential, and public activities. This represents the demand side of
the process, which must be matched against the supply of land. Land
supply is evaluated according to availability (vacant or unused land) as
well as to the available land's suitability and capacity for the various
proposed activities. Availability is determined through an inventory of
existing land use.
The suitability and capacity of a parcel is defined in terms of
accessibility, size, and general physical quality. Quality denotes
environmental characteristics to a varying degree. "Generally, considera-
* F. Stuart Chapin, Urban Land Use Planning (Urbana, Illinois: University
of Illinois Press, 1965).
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tion is given to a parcel's buildability, considering soil and slope
conditions. The basic assumption of this approach is that economic
growth will bring positive benefits to the community and that such growth
can best be fostered by designing the land use pattern to maximize acces-
sibility within the system of economic activity."*
This approach to land use from a purely economic point of view has
been coming under increasing scrutiny because of increasing sensitivity
to environmental effects. Future land use planning procedures will
evaluate the suitability of land for certain uses from the point of view
of cost to the developer, from the perspective of land as a resource to
be protected from misuse, and from the perspective of potential environ-
mental impacts of its development.
This process results in a document that is the basic element of the
comprehensive plan. It is generally presented toward the end of the
report as a composite of those functional plans for specialized types of
land use. The generalized land use plan for the area usually does not
show individual detailed parcel uses. The land use areas are broad, and
the boundaries are sometimes imprecise. For the exact location of faci-
lities or parcel uses proposed, sector or neighborhood development plans
should be reviewed.
In a very few large urban areas, e.g., Baltimore, Dallas-Ft. Worth,
and San Diego, the land use and land activity patterns have been quanti-
fied for a computerized land use/land activity model. This procedure
permits evaluation and projection of land activity over time; however,
at present, it is not readily available in most urban areas and con-
sequently is not discussed in this chapter. Detailed discussion of the
land use models may be found in Appendix C, and the application of such
models may be found in Appendices A and B.
* Edward J. Kaiser, et al., "Land Use Planning: The Cornerstone of Local
Environmental Planning and Control," Land Use and Environment, edited
by Virginia Curtis (Washington, D.C.: EPA, 1972), p. 104.
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The following sections discuss the land use plan in greater detail
to provide the evaluator with the necessary information to use the plan
in the determination of the air quality for an area. Particular atten-
tion is given to the preliminary studies that form the basis for the
plan as well as the data that they provide, which may have applicability
for air quality analysis.
1. The Land Use Plan
The land use plan, as a pattern for existing and proposed activities,
provides a map of potential patterns of emissions. For the purposes of
air quality modeling, one way of looking at sources of pollution is to
place them in one of the following categories:
t Point Source - A single major emitter located at a point. A
similar type of source is that designated as "stationary."
• Line Source - A major highway link or other transportation link
denoted by its end points. This source is also occasionally
referred to as a "mobile" source to differentiate it from
"stationary" above.
• Area Source - An aggregation of smaller, less specific sources
that are spatially distributed over an area. This includes resi-
dential emitters, single emitters, and highway links deemed too
small to be considered as individual point or line sources by
the model. The boundaries of the area are not fixed. They may
or may not coincide with those of political jurisdictions. The
total area may be partitioned into squares and referenced to
some type of grid coordinate system if this is the form the
model requires.
The degree to which public facilities and major transportation
facilities are detailed on the land use plan may vary considerably from
agency to agency. Proposed public land uses may be shown on the public
facilities plan or land use plan; hence, those will provide a basis for
part of the air quality analysis. In order to consider major transpor-
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tation sources of pollution, the transportation element of the compre-
hensive plan or the 3-C transportation plan (see Part B of this chapter)
can be used as a base.
The information used in the calculated demand for a particular land
use can be used in the projection of air pollution emissions as discussed
below. In addition, the supplementary information presented in each
functional plan is evaluated for its utility in air quality projections.
In general, the minimum information produced through the studies
done prior to the development of the land use plan includes:
0 Current and Projected Urban Population - These studies are
concerned with the total and future population size, as well as
its composition in terms of such qualitative considerations as
age groups, household sizes, and income composition.
• Current and Projected Urban Area Employment - Employment is
measured by major SIC (Standard Industrial Classification)
categories or grouped under broad employment activities such as
manufacturing, wholesale, and office-related.
• Existing Land Use - Land use data is summarized both statisti-
cally and in map form according to ground use categories such
as residential, commercial, and industrial.
• Housing - The current stock of housing is summarized by type of
structure.
e Vacant and Renewal Land - A map showing vacant areas, as well
as a tabular summary, indicates the general suitability of
parcels for development.
The specific types of studies often preferred to determine the
allocation of land include economic, employment, population, activity,
and urban land. These studies are examined briefly below, with each
discussion describing the types of methodologies that can be used to
obtain the relevant statistic. This is then evaluated for its utility in
projecting air quality.
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a. Urban Economy - "The destiny of an urban center is controlled by the
extent and character of its productive or income-producing activities and
their general vitality. Studies of the economic basis of these activities
hold the key to how the city has developed, where it is today, and what
its future prospects are."* Viewed in this way, the economy conditions
the amount of development that occurs, and, hence, influences land use
projections. With a knowledge of the trends in the economy, the planner
is better able to develop yardsticks that can be used in estimating land
requirements. "As an example, studies of employment are a key element in
population forecasts, and population estimates are, in turn, used for
scaling land development needs. Estimates of future land requirements
for industrial uses are based on manufacturing employment trends, and
future space needs for commercial uses draw upon employment trends in
wholesale trade, etc. Finally, plans for various sizes of shopping
centers draw upon studies of population and purchasing power in and
around the urban center."**
Two standard approaches to economic projections are the regionally
oriented and the urban centered. Whichever approach is taken, the results
are a set of statistics showing the projected growth for various types of
industry in the area. These are then used as a base for other types of
projections.
Regional orientation - The underlying assumption of this approach is
that economic activity in the urban center is affected by other centers
of economic activity in its immediate region and is ultimately linked to
the national economy as a whole. Hence, a city's future economic position
is dependent on its capacity to develop new productive resources and to
expand existing ones in relation to other cities in the region engaging
in the same activities.
* Chapin, Op. Cit., p. 107.
** Ibid., p. 107.
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Presented below are three approaches to the study of regional spheres
of influence:
• Input-Output Analysis - This approach is concerned with the
dynamics or commodity flows among aggregates of industry.
These aggregates (focal points) can be single urban centers or
a whole metropolitan complex of centers.
• Regional Accounts System - This is designed to analyze all
forms of income-producing activity.
• Approximation Analysis - Using conventional divisions of the
nation into regions, subregions, etc., and by crude step-down
procedures from the larger parent area, gross measures are
developed of how the parts of the whole are estimated to share
in total national productive activity.
Urban-centered - The assumption that the analysis begins in the
urban area but at the same time is extremely focused in that it seeks to
explain the city's economic structure in terms of the goods and services
that it produces that are consumed outside of the localized area of
study. It identifies it as the "base of the urban economy the goods and
services that are consumed externally!1*
The primary urban-centered approach to the calculation of economic
growth is the economic base, which has received rather extensive appli-
cations in city planning analyses. Base theory considers the structure
of the urban economy as made up of two broad classes of economic efforts--
(1) the basic activities which produce and distribute goods and services
for export to firms and individuals outside a defined localized economic
area, and (2) the service or nonbasic activities whose goods and services
are consumed at home. The concept holds that growth in the basic sector
usually means growth in service activities and, thus, growth in total
economy.
A Iccal economic base is the preferred method of determining which
proportion of current employment is engaged in activities that produce
* Chapin, Op. Cit., pp. 108-109.
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for export, and which proportion is engaged in activities producing for
local consumption.
b. Employment Studies - Employment forcasts serve two functions in the
land use planning process: (1) they provide information of concern to
population studies which, in turn, are used in estimating space needs for
residential areas, shopping centers, and community facilities; and (2)
they supply a direct yardstick for use in determining the land require-
ments for industrial and non-retail commercial areas.
In industrial areas, space requirements are estimated on the basis
of adopted industrial density standards, i.e., manufacturing workers per
acre of industrially used land or standards of a more detailed nature
based on floor area, shift size, and structural density. In wholesale
areas, space requirements are derived from various floor area standards
of employees per square foot of building space. Office space require-
ments are developed on the basis of floor area standards relating employ-
ment to space taken up by the category of use.
Various sources of employment statistics are available for use in
projecting future employment. The U.S. Bureau of the Census provides
statistics on total labor force, civilian labor force, total employment,
and manufacturing employment.
There are various methods of projecting employment; several commonly
used methodologies are described below.
Input-Output Analysis - Using the estimates of the effective demand
for all the various economic lines in the study area for a particular
year and estimates of labor productivity for all industries and for the
subcategories of manufacturing, finance, insurance, and real estate as
given, the actual employment projections are obtained by dividing values
of estimated future output by the appropriate values for output per
12
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worker. The method, however, presents a great many problems, particularly
with regard to the availability of data in the form needed to undertake
the analysis.
Income Statistics - The income approach is an alternative to the use
of dollar measures of transactions between industries and worker produc-
tivity (as the components of the ratio for deriving employment). It
utilizes a broader, more inclusive accounting system involving income and
product statistics. In this instance, concern is with all forms of
income-producing activity, investment, and trade, as well as industrial
production.
Apportionment and Ratio Methods - These procedures use employment
statistics directly without involving projections of total ouput and
output per worker. Although these methods both use step-down procedures
in identifying the study area's share of a larger geographic area, the
first method accomplishes the step-down by an apportionment technique;
the other utilizes direct step-down, omitting the proration analysis of
all parts of the whole.
c. Population Studies - To be useful, growth potential must be express-
ed in terms of the population it can be expected to sustain in terms of
the size of the population, its composition and characteristics, and its
spatial distribution. Population size provides an estimate of space
requirements for various land use categories. Investigations into popu-
lation composition assist in estimating residential space requirements
for various types of dwelling units consistent with family size, income
level, etc. They also assist in determining the amount of space needed
for recreation areas, schools, and other community facilities. The
examination of residential population distribution spatially provides a
basis for the location of the various facilities.
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Sound demographic analysis is predicated on accurate population
data, which includes public census enumerations, unpublished census data,
and vital statistics.
To be useful in planning studies, this data has to be used in (1)
estimating current population and (2) projecting future population in the
study area.
Estimates of Current Population - One of the first studies to be
accomplished is the estimate of the current population. Up-to-date popu-
lation estimates are so vital to all types of planning work that many
agencies develop new estimates annually. The most common forms of these
methods are summarized below:
• Migration and Natural Increase - This procedure, used exten-
sively by state agencies, is one of adjusting the last census
figures of the locale of interest to reflect changes that have
occurred to date, considering the effects of migration and
natural increase separately.
• Censal Ratio Methods - These are used by both state and city
agencies and include any method utilizing ratio procedures.
The simplest form of the ratio procedure makes a direct step-
down from Bureau of the Census state population estimates to
one particular county or SMSA without examining trends in other
counties. This should be used, however, with caution.
• Methods Based on Symptomatic Data - These methods, widely used
by city planning agencies, derive estimates of the current
population by reference to observed trends in data series that
are found to have a close relationship to population change and
for which current data are available. The vital statistics
used include school enrollments, electric meter, water meter,
or telephone installations and registered voters.
Population Projections - Perhaps the single most important population
study for planning purposes is population projecting. The following
lists some of the most common projection methods used in small area
studies:
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The Cohort Survival (or Cohort Component) Method - This rather
complex method requires an experienced population analyst to
execute the projection. The method adjusts figures from the
last census forward by age and sex groups (cohorts) year by
year to the projection date, with separate adjustments made
for each of the three major components of population change:
death, birth, and net migration.
Migration and Natural Increase Method - This method starts
with a current estimate of the population, and by introducing
adjustments first for migration and then for natural increase
on a year-by-year basis, it develops annual estimates into the
future until the projection date is reached.
Apportionment and Ratio Methods - These approaches employ a
previously prepared projection for some larger geographic area
and, by step-down procedures similar to those for employment
projections using this methodology, establish how the local
area may be expected to share in the projected population of
the larger area.
• Employment Method - Where employment forecasts have previously
been prepared for the study area, this method is often used as
a basis for making population projections. Using ratios, the
method expands future employment figures to labor force esti-
mates, and these are then expanded to population equivalents.
• Mathematical and Graphical Extrapolation Methods - This in-
cludes arithmetic and geometric projections, trend extrapo-
lation by the method of least squares, and estimates based on
the logistic curve.
Population Distribution- Projections of the distribution of future
total population among the various neighborhoods have obvious implications
for the study of residential areas and their community facilities. The
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distribution of population is commonly based upon (1) an analyses of
daytime population distribution, and (2) residential distribution.
d. Urban Activity Systems - This type of analysis is not yet a standard
part of the land use planning process. Traditionally, planning agencies
have gone into land use studies looking at the effects of activity sys-
tems rather than seeking to define and understand activities themselves
as producers of land use patterns. It should be recognized that there
are no fully tested techniques of analysis for this component.
One method in existence is the origin and destination survey done in
transportation planning. In the survey, the respondent is asked to
identify major activities of various members of the household during the
preceding 24-hour period, or he may keep a diary over a longer time
frame. The object of the survey is to be able to to identify specific
recurrent behavior patterns that will then enable the planner to make
analyses of space use and travel in order to develop an integrated set of
proposals for land use and transportation for the comprehensive plan.
e. Urban Land Studies - These studies focus on an investigation of the
features of the land itself. The information obtained describes the uses
for which a particular parcel of land is most suited from a physical
perspective. This information often indicates constraints on a particular
type of use that could potentially be located on a parcel. It also
provides an indication of how the population is distributed throughout
the study area. Specific types of studies that would provide this type
of information include compilation of data on physiographic features,
existing land use surveys, vacant land surveys, hydro!ogical and flood
potential studies, and studies of aesthetic features.
For reference, the following types of maps may be used: aerial
photographs, engineering maps, topographic and soils maps, and property
tax maps.
16
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2. The Utility of the Land Use Plan
A wide variety of information goes into the development of a land
use plan. The question then is whether these sources are useful in
projecting air quality for the area covered by the plan.
The basic method for the prediction of future air pollution concen-
tration levels expected from the implementation of a land use plan is
through the use of an atmospheric dispersion model. Models of this type
translate data on emission patterns into patterns of expected concen-
trations for given time frames. In addition to emissions data, disper-
sion models require meteorological and topograhic data in order to make
estimates of concentration patterns. Also, local air quality measure-
ments are needed to evaluate and refine model performance and to specify
confidence limits for the model results.
As mentioned in the introductory portion of the land use discussion,
one way of approaching the calculation and projection of emissions is by
dividing sources into three generalized categories—area, line, and point
sources. This is not the only way to classify sources of pollution, but
it does relate well to land use concepts; hence, the utility of land use
data is evaluated within this framework in the following discussion.
a. Area Sources - In order to calculate this category of emissions, it
is necessary to know the location of residential areas, the types and
densities of housing, and population size and distribution.
This information, traditionally supplied in a general land use plan
and accompanying text, should be adequate to provide a basis for the
calculation of area sources. Population figures also provide a rough
estimate of the number of automobiles owned for projecting travel. The
housing densities and types generally indicated on the map will give an
indication of the number of heating units that can be expected. In
areas indicated for potential high density development, emissions from
17
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incinerators, if permitted by law, will also have to be taken into con-
sideration. An additional piece of information needed in order to cal-
culate emissions from heating units is the source of energy. This can be
obtained from the utility companies in an area or the local planning
agency.
Once the sources of emissions have been determined and the potential
levels have been established, the evaluator must know the physical
characteristics of the area—particularly variations in topography and
wind patterns—in order to estimate actual pollution levels. These two
factors, of course, will have an effect on whether the pollutants are
dispersed or whether they accumulate over an area. In conjunction with
this, the proximity of significant amounts of open space should be taken
into account, as it has an effect on ameliorating pollution concentra-
tions. Information on open space is also presented on the land use map.
Other components of area source pollution are local commercial and
office facilities (with the exception of regional shopping centers).
These are indicated on the land use map. Detail as to the type of
facility can often be gained through an examination of the existing land
use map and the zoning map and ordinance.
Zoning ordinances frequently differentiate among types of commercial
uses and often require different amounts of parking space be provided.
As previously discussed, the amount of space allocated for commercial use
is based on economic forecasts for the area plus consideration of popu-
lation and disposable income. This type of information gives an indica-
tion of the number of cars that will be attracted to an area which can
be related to automotive emissions. Some of these zoning requirements
may be shifting as a result of the parking plans being developed as part
of the transportation control strategies in many urban areas. Commercial
areas also produce emissions from heating and, possibly, incinereition
facilities which should be included in the calculations. These totals
from small scale commercial facilities are then included in the area totals,
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b. Point Sources - The land use plan, through the studies of industrial
demand and the capacity of particular sites for specific industrial uses,
provides an indication of potential locations for industrial point sources.
Depending upon the level of detail included in the plan, particularly the
industrial plan, the broad industrial categories of light, medium, or
heavy industry may be indicated on the land use map. If the map is for
a less developed area, it may only show one general purpose industrial
category. In the latter case, it will be more difficult to determine
which areas will, in fact, represent point sources. It should also be
noted that the differentiation into several industrial land use types
does not indicate the process used or the pollutants emitted.
The distinction made in most zoning ordinances is between light and
heavy manufacturing. The difference between the two is based on the
degree of noxious effect—noise, odor, dust, etc. The regulations
themselves merely list permitted or prohibited industries by industry
type. Many of the newer zoning ordinances, however, are prescribing
performance standards for industry. These define the maximum amount of
noise, smoke, dust, and other external effects that an industry in a
given district may produce. If this type of ordinance exists, the
maximum levels of emissions by zone may already be known.
Performance standards for industrial districts should be viewed with
caution, however, as some jurisdictions do not have the technical capabil-
ities within the planning or zoning department to enforce the standards.
In addition, the performance standards for air quality should be reviewed
to determine if they do in fact provide for the control that was intended.
In other areas the local air pollution control agency can and does enforce
performance standards.
Many areas also do a special industrial survey that locates specific
types of industry in areas with which they are most compatible. For ex-
ample, in the comprehensive plan for the City of Philadelphia, the city
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is partitioned into five zones, each with characteristics of particular
interest to industry. These zones are matched with the most suitable
industrial type, designated by a three-digit SIC code. This level of
specificity, while not locating the exact parcel on which a particular
industry is sited, does provide approximate areas where pollution con-
centrations of a certain type may be expected. If this type of informa-
tion is available, it would be as an adjunct to the land use plan and
should be consulted for use in air quality projections. In any case,
industries in the area should be consulted on any plans that they might
have for the expansion of facilities. Business or real estate pages of
local newspapers often tell of plans for new facilities or industries
moving into the area. Chambers of Commerce or local or state industrial
development commissions are added sources of information.
The location of public utilities is usually determined by the
utility companies. The local planning agency obtains the information
from them and reproduces it on a land use map. As utility companies
often buy up land in anticipation of need, the projections could reflect
this additional knowledge. Depending on the regulations of the state and
whether the utilities are publicly or privately owned, they may not be
subject to local zoning. In the case where they are not, pollution from
other sources may have to be reduced in order to meet the standards where
a power plant is to be located in an area.
c. Line Sources - The information gained from the land use plan does
not really contribute to the calculation of line sources of pollution,
which represent emissions from motor vehicles along principal highways
and roads and emissions from aircraft. The studies previously discussed,
particularly the urban activity systems, can contribute information to
line source calculations. The best data is generally available from the
3-C transportation plan, as described in Section B of this chapter.
20
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Information from the 3-C process includes trip origins and destinations,
vehicle miles of travel, average traffic counts, the proportion of trips
on transit, and an estimate of speed.
3. The Influence of Land Use Planning on Development
In order for a land use plan (or a comprehensive plan) to be useful
as a tool in achieving the objective of air quality maintenance, it must
be supported by an enforcement mechanism. If the planning agency or
local government does not have the legal power to enforce the plan, then
there is no assurance that the plan as developed will ever be implemented.
The knowledge that the plan forming the basis of the projections will be
implemented also increases the validity of any projections that are made.
The power of a plan as part of an overall strategy depends not only on
the ability to enforce it but also on the role of a particular plan in
the total planning picture. If the plan is part of a total planning
process, ranging from the micro, or local, to the macro, or regional,
level, then the information it provides has greater applicability and is
more useful.
The following sections discuss both of these elements—the mechan-
isms for enforcement and the integrative aspect of the plan.
a. The Mechanisms for Enforcement - Various types of controls can con-
tribute to the enforcement of the plan. The first level of control lies
with those responsible for the development of the plan and its subsequent
implementation. Generally, the comprehensive plan and the component land
use plan are developed by the planning agency. The land use plan is a
guide, and as such it is not legally binding. The comprehensive plan,
while not passed as an ordinance, is generally adopted by the legislative
body as a policy guide by resolution. The land use plan, however, does
form the basis for the zoning ordinance, which is one of the legal mechan-
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isms for ensuring that the plan is implemented. One problem is that in
many places the zoning ordinance preceded the plan, which makes rational
development more difficult. In other cases, the zoning ordinance may
exist without the plan, which means that development can be haphazard.
As land use planning has traditionally been a local concern, the
greatest power for enforcement (particularly in the form of zoning) exists
at the local level. In one study*, it was found that the agencies with
jurisdiction over large areas—state, regional, or county—typically have
an extremely limited power base as they are made up of components which
have their own authority in the area of land use, as defined by state-
enabling legislation.
In a study of the Baltimore-Washington area, it was found that the
strengths of land use controls declined as one moved from the central
zones outward. Hence, areas experiencing the most rapid change in land
use are least equipped to control development, as they often have no
zoning. In addition, the planning authority in the region is fragmented;
hence, the patterns of land development have largely been shaped by the
uncoordinated actions of thousands of private developers and multiple
jurisdictions. This means, of course, that the larger the geographic
area covered by the plan and the larger the number of component juris-
dictions, the less likely that the areawide planning agency will have the
tools necessary to enforce it.
Dissatisfaction with the results of local land use controls has
caused many states to adopt statewide or regional approaches to land use
planning. In Alaska, Colorado, Connecticut, Delaware, Georgia, Hawaii,
Maine, Maryland, Massachusetts, North Carolina, Rhode Island, Vermont,
and Wisconsin, either a new state organization or an existing agency is
required to implement some degree of statewide land use planning or
* Byron H. Willis, "The Hackensack Meadow!ands Air Pollution Study
Summary Report," (Lexington, Massachusetts: Environmental Research
and Technology, Inc., 1972).
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zoning or both, or to carry out some sort of planning and land use
regulation aimed at particular classes of land such as wetlands or tidal
areas. "In addition, in some states--such as California with the San
Francisco Bay Community Development Commission or the Tahoe Regional
Planning Agency, New Jersey with the Hackensack Meadowlands Development
Commission, or New York with the Adirondack Park Agency--a regional
agency has been created to deal with some special problems of land use
planning and control. These various measures are primarily directed at
resource use problems."* However, they are significant in the fact that
they do represent a break with past sole reliance on local land use
planning. Some establish state controls that replace local controls;
others provide a combination of state and local controls with the state-
wide concerns clearly dominant.
Regional zoning, as differentiated from state level controls, is
much more rare, existing only in Jacksonville, Florida; Indianapolis,
Indiana; and Nashville, Tennessee. This is due to the consolidation of
governments in these areas. The statewide and regional approaches to
land use planning and control are, however, too recent to have been fully
tested for either their competence, efficacy, or legal powers."**
It should be noted that although an area may have a plan and a
zoning ordinance to enforce it, there are ways to change zoning and, in
that way, to compromise the land use plan. At the local level, a legis-
lative body or planning commission may grant a rezoning, or a zoning
board of appeals may grant a zoning exception or variance. This type of
flexibility in the zoning pattern is not necessarily bad, as it may allow
for the introduction of innovation, amelioration of a hardship or grie-
vance, correction of a mistake in the original zoning, or accommodation
* Marion Clawson and Harvey S. Perloff, "Alternatives for Future Urban
Land Policy," Modernizing Urban Land Policy, edited by Marion Clawson
(Baltimore: Johns Hopkins University Press, 1973), p. 222.
** Ibid., p. 222.
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to changed conditions. However, it does decrease the reliability of
projections based on the plan.
The existence of effective land use controls is critical to the use
of land use planning for maintaining air quality. There are presently
several techniques for controlling urban and suburban growth and develop-
ment, including:
• Location and timing of public improvements such as roads,
sewers, sewer treatment plants, and water lines.
• Lending policies and the restrictions which may be imposed by
private lending agencies and the government agencies that
supervise them or insure their loans
t Government subsidies, loans, and other programs for renewal,
development, and redevelopment
• Public land use controls - zoning, subdivision regulations,
building codes, health regulations
• Tax policies that would encourage the inclusion of environ-
mental objectives into the private decision-making process
Many of these elements are generally delineated in the Capital
Improvements Plan which is the planned budget for 2 to 5 years for the
local jurisdiction.
The following section discusses zoning in greater detail as it is
the predominant mechanism for land use control. In general, the zoning
power may be transferred by the state, through enabling acts to the
governments at either the local, county, or regional level. Some states
authorize all three types of zoning while others restrict power to the
local level. This decision is generally based on the nature of develop-
ment within the state and the system of land use control that would
appear to be appropriate.
As the concerns of a municipality, county, and regional agency
usually vary considerably, the zoning ordinance, in terms of the provi-
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sions and the districts or zones defined, will also vary. Zoning at the
regional level, where it exists, will differ from that of the munici-
pality or the county in that it represents a coordinating function and
usually will be carried out by a body with representation from the
constitutent counties. A regional planning commission constituted in
this fashion may have the authority to prepare various zoning codes and
ordinances for its area, but these must be approved and adopted by the
constituent counties before they have the force of law.
At the local level, where zoning has been the traditional regulating
mechanism, it has been shown that "zoning controls have been of limited
value in guiding new suburban land development. The typical suburb is
either unable or unwilling to enact zoning and other controls that are
strong enough to effectuate a general plan for the area. The difficulty,
however,, has been political, not legal."*
Because of the local basis for zoning, the regulations have often
proved obstructive to the development of land use plans at a broader
scale. In the past, land use zoning was used by units of local govern-
ment for local ends; hence, when it came to the issue of overall economic
and social development, and the implementation of a metropolitan strategy,
local land use zoning and controls have been notably deficient. The
result has been that development has generally assumed the form of
uncontrolled sprawl.
Gradually, however, there has been a change in the thinking about
land use regulation away from the belief that the purpose of the regula-
tion was for the protection of the commodity value of land. There is a
realization that important social and environmental goals require more
specific controls on the use that may be made of scarce land resources.
This change in attitude is seen not only in the new state role in land
Marion Clawson, "Editor's Introduction," Modernizing Urban Land Policy,
ed. Marion Clawson (Baltimore: Johns Hopkins University Press, 1973),
p. 6.
25
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use regulation but also in the actions of many local governments.
Modern zoning ordinances typically rely less on pre-stated regulations
and require the developers to work with local administrative officials in
designing a type of development that fits more closely into the surround-
ing area. Typical of this new direction are planned unit development
(PUD) zones which encourage larger scale development in which the various
land uses are arranged and designed according to an overall plan for the
specific site as opposed to the traditional lot-by-lot development.
There is also a greater tendency on the part of local governments to
develop more specialized use districts that permit only those uses
appropriate to the geographic area rather than to some abstract category
of uses. This is evidence of the growing attempt to tailor land use
regulations to local needs. Finally, and probably most significantly,
for the purposes of planning, there has been a rapid increase in "recent
years in local zoning and subdivision regulations in relatively undevel-
oped areas. Here the concern is with the development of optimal long-
range land use patterns."* This new, more comprehensive approach to
zoning may eventually eliminate the over-use of re-zoning, exceptions,
and variances that tend to distort the patterns.
b. The Integrative Aspect - If the land use and comprehensive plans are
to be useful tools, they should be part of a comprehensive integrated
effort to achieve this objective; the broader the base of the plan, the
more likely that it will have some effect. This section discusses how
the planning agency interfaces with other agencies that might provide
specialized information, as well as the relationship of the plan to other
land planning efforts.
As the concern for the environment is only just beginning to be
incorporated into the comprehensive land use plenning process, there has
* Fred Bosselman and David Callies, The Quiet Revolution in Land Use
Control (Washington, D.C.: Government Printing Office, 1971), p. 317.
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traditionally been very little need for coordination between the local
planning agency and any existing environmental agencies in the area. The
present concern with expanding the definition of the comprehensive plan
to include environmental considerations, and the requirements of the Na-
tional Environmental Policy Act (NEPA) and the A-95 Review have probably
resulted in an increased level of interaction between these two groups.
In the area of air pollution, the Hackensack Meadowlands Air Pollution
Study has indicated that there is a lack of a clear distinction between
the responsibility of the planner for the abatement of air pollution
problems in the long term and that of air pollution control officials.
It was found that many planners felt that it is not within their juris-
diction to incorporate air pollution into the planning process, but
rather felt that more effective solutions could and should be achieved by
direct control of emission sources through the air pollution control
agencies and their powers of regulation and enforcement. It would appear
that a greater coordinative effort is necessary so that both strategies
are implemented, as well as being mutually supportive. This type of
coordination is particularly important for the control agency so that
control strategies can be closely related to the land use patterns that
are developed.
The relationship of a plan to plans of a larger and/or smaller scale
depends to a large extent on the existence of a standard system of land
use categories throughout the area under consideration. There has been
a great problem of comparability of plans as many areas use their own
definitions and collect different types of data at different levels of
detail. This means that local land use plans cannot always be summed to
produce a regional plan. There are examples where the land use plan for
a region does represent a compilation of the land use plans of the
component jurisdictions. In this case, greater specificity in regional
projections can be gained from looking more closely at the studies that
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went into the land use patterns for each of the component jurisdictions.
Because of the variability of the plans, it is difficult to say where
regional and local plans are compatible and where they are not.
A significant source of conflict may occur in the case where local
plans may reflect community goals over which they have very little con-
trol. For example, a no-growth policy in some local jurisdictions may be
an appropriate response to the community's ability to provide adequate
facilities and services. However, the local government may possess
neither the regulations nor the will to withstand private development.
On the other hand, especially in less developed areas, local "boosterims"
and wishful thinking may result in vast areas being planned and zoned for
commerce and industry with little support by economic realities. The
evaluator will have to make a decision on a case by case basis.
c. The Planning Document as a Reliable Source of Information - The
degree to which land use plans and zoning maps will be useful to air
pollution control will vary widely from agency to agency because of the
uncertainty inherent in the findings and recommendations contained in
planning documents. Some of the factors that must be taken into con-
sideration are:
• A characteristic of almost all plans is that they are not
current. The base year for much of the socioeconomic projec-
tions is information from the census. Techniques for updating
such information vary considerably. Land use inventories are
continuously updated in some agencies, while others may be
several years old. In addition, local actions affecting the
plan may not be reflected on the plan.
• Many plans may be so general as to be of little use as a guide
for quantifying and locating future problems in air resource
management. In such cases, the text of the plan may be more
important than the map, as specific development policies or
guidelines may be well articulated. For example, the planning
map may not indicate the location of commercial facilities
while the text may describe locational criteria, service
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areas, range of facilities according to function, size, etc.
In the decision-making process, then, the planners would not be
committed to a specific location in advance but would measure
private development proposals against these criteria set out in
the plan.
• Planning maps may indicate significant areas for urban develop-
ment which would not necessarily be reflected on the zoning map.
In such cases, the local strategy is to "under zone," thereby
requiring all potential developers to appear before local
planning and zoning boards and legislative bodies to gain plan
approval. Under such circumstances, the local government is
likely to have more influence on the type of development that
occurs than if the developer already has the appropriate zoning.
The plan indicates the proposed land use and provides a guide
for zoning action.
4. The Potential for Change
An effective comprehensive plan is not a static document but rather
represents a dynamic process that is regularly updated to reflect new
conditions and objectives. The incorporation of new information with
regard to the relationship between land use air quality and other environ-
mental aspects such as water quality, should be part of the updating
procedure. The review process is particularly important for plans in
areas that are still developing but are already experiencing air pollution
problems.
The basic guidelines for the development of a comprehensive plan
suggest that the plan should be reviewed annually. "Once a year the
legislators should re-examine the plan and consider possible amendments."*
These amendments would normally be initiated by the planning staff. They
would then be screened by the planning commission and forwarded to the
legislators. 'The importance of the annual review cannot be overemphasized.
* Alan Black, "The Comprehensive Plan," Principles and Practice of Urbjm
Planning, edited by Goodman and Freund (Washington, D.C.: ICMA, 1968),
p. 370.
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This is the main process which is intended to assure that the plan will
be kept up to date. If it is neglected it is possible that the plan will
"ossify" and be ignored. Annual review, however, is a fairly recent
innovation."*
There should be a major reconsideration of the entire plan after
five or ten years. This should provide for an overhaul of the entire
plan, including new surveys, updated projections, and the restudy of
major alternatives. The effort expended on this should be similar to
that put into the original plan, and the same general procedures should
be followed. The rationale behind this step is that amendments made at
annual review time will not suffice to keep the plan current after an
extended span of years. Gradual changes (particularly those caused by
rezonings, variances, and exceptions) may be imperceptible.
The ability to change the plan may not always serve the best in-
terests of those interested in air quality. That is why it is incumbent
upon those who have responsibility in this area to review plans at
the operative level and to provide inputs that will provide a basis for
developing plans that contribute more to the achievement of air quality
goals.
B. THE 3-C PROCESS
The term "3-C process" comes from the Federal-Aid Highway Act of
1962 which requires that all programs for Federal-Aid Highway Projects
approved after July 1, 1965, in urban areas of more than 50,000 popula-
tion must be based on a Continuing, Comprehensive transportation planning
process carried on Cooperatively in the state and local communities.
1. Current Practice
Generalizations about the process and procedures followed in the
planning studies are very difficult because no two studies follow identi-
* Ibid., p. 370.
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cal methods or procedures. All studies vary widely in terms of the level
of detail for specific portions of the study and the analytical process
used to analyze and evaluate data in the planning process.
Although the 3-C transportation planning process has been implemented
for several years, the level of sophistication and the degree of accuracy
of the plans varies considerably throughout the nation. In many of the
larger urban areas travel simulation models have been calibrated to local
conditions and validated over time so that the accuracy of the models is
known. In other areas the updating and validation procedures have not
been so well performed. However, the Federal Highway Administration,
through the certification process which accepts the plans and, thus
approves projects, for Federal funding, tends to ensure the reliability
of the 3-C process. It should be noted, however, that the process as
described below is not always rigorously followed; nor will all of the
elements necessarily be readily available to air quality maintenance
planners.
While there is considerable variation in the detailed procedures
used in each study, the comprehensive planning process requires that
certain concepts are common to all 3-C planning efforts. These include
evaluations of existing and future economic, population, and land use
data; estimates of future demands for all modes of public and private
transportation; inventories and analyses of all existing transportation
facilities; the development of a comprehensive transportation plan; and
the implementation of a continuing program to monitor and, as necessary,
revise the original transportation plan. The guidelines for implementing
the 3-C process are documented in a series of Policy and Procedure Memo-
randa (PPM) prepared by the Federal Highway Administration (FHWA).
Copies may be obtained from the regional FHWA office or the local 3-C
transportation planning agency. (The relevant document is PPM 50-9.)
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Figure II-l shows the generalized activities of almost all 3-C
planning processes grouped into the following four phases:
• Phase I: Data Collection - Various surveys are conducted to
provide a detailed picture of existing travel and socioeconomic
conditions in the study area.
• Phase II: Analysis - Analytical methods are used to develop an
understanding of the factors influencing travel demand and
develop procedures for projecting future travel demand and
transportation requirements.
• Phase III: Projections and Plan Development - Anticipated land
use and land activity are projected to future years, travel
demand in the study area is forecast, alternative transportation
strategies are developed and tested, and a final transportation
plan is developed.
• Phase IV: Implementation and Continuing Planning - Under a
continuing program to monitor the planning concepts used in the
development of the original transportation plan, the transpor-
tation strategy developed in Phase III is implemented and its
effectiveness monitored.
The end results of this process are twofold. First, based on a
detailed investigation and analysis of the existing situation, a transpor-
tation plan and program can be developed that serves as a common framework
for all agencies charged with transportation systems improvement, and
operation in the study area. Second, it provides the basic information
and procedures for continually reviewing the appropriateness of transpor-
tation strategy as required by changing events and changing community
goals and objectives. In almost all major urban areas, the transportation
planning process is in Phase IV, Implementation and Continuing Planning.
2. Legislative Requirements
The Federal-Aid Highway \ct of 1944 was the first Federal program to
provide regular Federal-Aid highway funds for use in urban areas. The 3-C
planning process in all urban areas with population over 50,000 was
32
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- PHASE 1
DATA
COLLECTION
BASIC INVENTORIES
AND SURVEYS
• Land Use
• Land Activity
• Financial
Resources
-PHASE II
ANALYSIS
- PHASE III
PROJECTIONS AND
PLAN DEVELOPMENT
rPHASE IV
IMPLEMENTATION
AND CONTINUING
PLANNING
EXISTING TRAFFIC
VOLUMES AND PATTERNS
• Auto
• Truck
• Taxi
• Public
Transportation
TRANSPORTATION
FACILITIES
• Highways
• Public Transit
• Travel Time
• Parking
• Terminal &
Transfer
Facilities
• Accident Records
MODEL DEVELOPMENT
• Land Activity
• Trip Generation
• Trip Distribution
• Modal Split
FUTURE LAND USE,
LAND ACTIVITY AND
ECONOMIC ACTIVITY
FUTURE
TRAVEL
DEMAND
ANALYSIS OF FUTURE
ALTERNATIVES
• Development
• Evaluation
• Selection
CONTINUING
PLANNING
• Surveillance
• Reappraisal
• Service
• Procedural
Development
• Annual Report
IMPLEMENTATION
• Priority Projects
• Capital
Improvements
Programs
Figure 11-1. Generalized activities of the 3-C planning process.
33
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established in response to Section 9 of the Federal-aid Highway Act in
1962, which amended Chapter I of Title 23, United States Code, by the
addition of a new section, 13A, which states:
It is declared to be in the national interest to encourage a.nd promote
the development of transportation systems embracing various modes of
transport in a manner that will serve the states and local communities
efficiently and effectively. To accomplish this objective the Secre-
tary shall cooperate with the states, as authorized in this title,
in the development of long-range highway plans and programs which
are properly coordinated with plans for improvements in other affected
forms of transportation and which are formulated with due considera-
tion to their probable effect on the future development of urban areas
of more than fifty thousand population. After July 1, 1965, the Sec-
retary shall not approve under Section 105 of this title any program
for projects in any urban area of more than fifty thousand population
unless he finds that such projects are based on a continuing compre-
hensive transportation planning process carried on cooperatively by
states and local communities in conformance with the objectives stated
in this section.
A description of all Federal, state, and local legislation as it
applies to the current 3-C planning process in all urban areas is beyond
the scope of this document. The following is a listing of the major
Federal legislation and regulations relating to the 3-C planning process
and air quality control.
Clean Air Act of 1970 (42 USC 1857 et seq.). Purpose: To require the
Environmental Protection Agency to review and comment in writing on
the environmental impacts of any matter relating to duties and
responsibilities granted pursuant to this Act or other provisions
of the authority of the Administrator when such impacts result from
a project to which section 102(2)(C) of the National Environmental
Policy Act of 1969 applies.
Federal-Aid Highway Act of 1970 (23 USC 109). Purpose: To require
the Secretary of the Department of Transportation to issue planning
and design guidelines to be applied to all highway projects which
are approved after the issuance of such guidelines. Under the FHWA
guidelines for Section 109(h) (PPM 90-4), each highway agency shall
develop an Action Plan which describes the organization to be utilized
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and the process to be followed in the development of Federal-aid
highway projects from initial system planning through design.
23 USC 109(h) directs the following:
Not later than July 1, 1972, the Secretary, after consultation
with appropriate Federal and state officials, shall submit to
Congress, and not later than 90 days after such submission, pro-
mulgate guidelines designed to assure that possible adverse
economic, social, and environmental effects relating to any
proposed project on any Federal-aid system have been fully con-
sidered in developing such project, and that the final decisions
on the project are made in the best overall public interest,
taking into consideration the need for fast, safe, and efficient
transportation, public services, and the costs of eliminating
or minimizing such adverse effects as the following:
(1) air, noise, and water pollution
(2) destruction or disruption of man-made and natural
resources, aesthetic values, communtiy cohension and
the availability of public facilities and services
(3) adverse employment effects, and tax and property value
losses
(4) injurious displacement of people, businesses and
farms
(5) disruption of desirable community and regional growth
Such guidelines shall apply to all proposed projects with respect
to which plans and specifications and estimates are approved
by the Secretary after the issuance of such guidelines.
23 USC 109(j) directs:
The Secretary of Transportation to assure that highways pursuant
to Title 23, USC, be consistent with any approved plan for the
implementation of any ambient air quality standards for any
air quality control region designated pursuant to the Clean Air
Act, as amended (42 USC 1857, et seq.).
The Urban Mass Transportation Assistance Act of 1970 and Section 204
oTthe Demonstration Cities Act of 1966, further clarified by Bureau
of the Budget Circular A-95.Purpose: To require submission of all
applications for the planning or construction of facilities using
Federal loans and grants to the designated areawide agency respon-
sible for metropolitan and regional planning prior to Federal appro-
val of the application.
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These agencies (A-95 Clearinghouses) have the responsibility for
reviewing and commenting upon all applications for Federal assistance
for public projects to ensure that "to the maximum extent possible,
consistent with national objectives, all Federal aid for development
purposes shall be consistent with and further the objectives of the
state, regional, and local planning."
Air Quality Guidelines for Use in Federal-aid Highway Programs
23 CFR 770). Purpose: To promulgate air quality guidelines for use
in planning and construction of proposed highway improvements con-
structed pursuant to United States Code Title 23. Under bhese guide-
lines, highway agencies planning, constructing, and maintaining
highways pursuant to 23 USC shall consult with appropriate local,
state, and Federal air pollution control agencies to ensure that
decisions on highways are consistent with approved State Implementa-
tion Plans and that adequate consideration is given to preservation
and enhancement of air quality.
3. Agencies and Groups Involved in the 3-C Process
All state highway agencies that propose projects for which plans,
specifications, and estimates are approved by FHWA must develop an "Action
Plan" as required under Section 109, Title 23, United States Code. The
"Action Plan" for each state highway agency specifies for that agency the
specific organizational structure and processes to be followed in the
development of Federal-aid highway projects from initial planning through
design. Therefore, the organizational structure and proceedings for each
agency vary to reflect the unique situation of each state. The guidelines
for developing the "Action Plan" are contained in PPM 90-4.
The organizational structure for individual 3-C planning studies that
are currently in the continuing planning phase can also be found in the
"Operations Plan for Continuing Urban Transportation Planning" developed
for each study. FHWA Instructional Memorandum 5-4-68 (IM-5-4-68) contains
the guidelines for the development of the operations plan.
The specific organizational structures for each of the existing 3-C
planning programs can be obtained by reviewing the appropriate "Operations
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Plan" and "Action Plan." The individual organizational structure for each
3-C program varies to some degree. In most studies the following types of
committees are formed:
• Policy Committee (sometimes called a Policy Board, Coordi-
nating Committee, Steering Committee, etc.). - This committee
is composed of local elected officials and representatives of
agencies or organizations designated by the state to provide
policy guidance and direction for the study. In most cases,
this committee also includes representatives of the state and
FHWA.
• Technical Advisory Committee - This committee generally consists
of staff appointed from the various state, regional, and local
governmental agencies participating in the study, plus repre-
sentatives of other agencies or organizations having special
skills in various study items or a special interest in the
transportation planning process. In general, it is the respon-
sibility of the Technical Advisory Committee to direct the study
and review all procedures for technical adequacy and to make
recommendations to the Policy Committee.
In some areas, citizens' committees have been formed to aid in the
establishment of communications between the technical staff and the public.
These committees also help provide lines of communication between the
public and the governmental units represented on the Policy Committee.
4. General Description of the 3-C Process
Generalizations about the 3-C planning process are difficult because
no two studies follow identical working methods and procedures. The
specific type of data collected, the level of detail, and the level of
analysis performed in each study vary to a considerable extent. The
following is a generalized description of the types of data collected and
the types of information developed in each of the four phases of the 3-C
process.
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a. Phase I: Data Collection - The major inventories and survey:; con-
ducted in the initial phase of the 3-C planning process can be combined
into three general classes:
Basic Inventories and Surveys - The land use and land activity
data in general are collected at the traffic zone level. The number of
traffic zones within a study area varies in total number from several
hundred to more than 4,000 and from a single block to many square miles
in area. Traffic zones are generally small geographic areas in the more
populated areas and large geographic areas in the outlying, less populated
areas.
The land use is generally measured in acres per zone and includes
the following classifications:
• Low density residential
• High density residential
t Industrial
• Commercial
• Agricultural
• Public and quasi-public
• Vacant
• Roads and streets
In some cases the land use codes contained in "The Standard Land Use
Coding Manual," Urban Renewal Administration and U.S. Bureau of Public
Roads, dated January 1965, are used. Land activity by traffic zone includes
• Population
0 Dwelling units
• Median and/or mean family incomes
• Auto registration
• Employment (by standard industrial classification code)
• Labor force
• School enrollment
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In most studies historical land use and land activity information and
trends are also surveyed and tabulated. Surveys are also made in many of
the studies to determine the financial resources available for the imple-
mentation of the transportation plan. These surveys include the source
and amount of revenue used for the construction, maintenance, and opera-
tion of transportation facilities for the previous 5 to 10 years.
Existing Traffic Volumes and Patterns - Three basic types of surveys
are made to determine the number, purpose, mode, and time of day trips are
made by all persons and vehicles within, into, out of, and through the
transportation study area. These three surveys are the home interview,
external, and truck and taxi surveys.
In the home interview survey, a sample of all dwelling units within
the study area is selected, and all trips made by the residents of these
dwelling units are recorded. The sample size varies from 12 percent for
small urban areas to 4 percent or less for very large urban areas. The
characteristics of the dwelling unit are also recorded in this survey.
These characteristics include number of persons in the household, number
of cars owned, total household income, number of persons employed, type of
employment, and age of residents. The data for each trip made on a given
day by each member of the household includes the purpose of the trip, the
origin and destination of the trip, the mode of travel (auto driver, auto
passenger, transit passenger, walk to work, etc.), the time the trip began
and ended, and the number of passengers in each vehicle.
In the external survey, 20 to 50 percent of all vehicles crossing the
boundary of the study area (called the external cordon line) on major
routes on a given day are interviewed. The origin and destination of each
trip, trip purpose, number of persons per vehicle, type of vehicle, time
of interview, etc., are recorded for each vehicle interview at the external
cordon.
In the truck and taxi survey, a 10 to 20 percent sample of all trucks
and taxis garaged within the study area is selected. All trips made by
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these vehicles on a given day are recorded. The same type of information
as collected at the external cordon line is recorded for each trip.
All of the trip interview data is expanded to reflect the sample
rates; it is checked, and verified so that travel information reflecting
all trips made on a typical day of the survey period is produced.
In some studies, an on-board transit survey is also conducted. In
this type of survey, a large sample of the transit riders is interviewed
to provide in-depth transit travel pattern data. Two common types of
transit surveys are direct interviews conducted on the vehicle by trained
personnel and the postcard survey in which questionnaires are distributed
to passengers on the transit vehicle.
From the expanded travel survey data, a detailed tabulation of the
number of trips made between any zones within the study area by time of
day, trip purpose, and mode of travel is developed.
Transportation Facilities - The third general class of inventories
and surveys conducted in the first phase of the 3-C planning process is a
detailed inventory of all transportation facilities within the area to
determine the quantity and quality of the existing transportation system.
Included are:
t Inventory of the characteristics of all highway facilities
including pavement width, right-of-way, intersection approach
width, all traffic control and traffic engineering features, as
well as surveys of existing traffic volumes. From this data,
existing levels of service and the capacities of the facilities
are determine.
• Surveys of the existing transit system and its usage. This
information includes location of routes by type of service,
transfer points, frequency of service, and operating character-
istics and statistics.
§ Travel time studies to determine the peak hour and off-peak hour
speeds on various segments of the transportation facilities.
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• Parking surveys to identify the quantity and usage of existing
parking in the major urban areas.
• Location and inventory of major goods terminals and transfer
facilities.
• Tabulation and analysis of accident data by location, type of
facility, and frequency as a measure of safety of the system.
From the facilities survey data, highway and transit "networks" are
developed. These networks are computer-processable representations of the
existing highway and transit system operating in the area.
The trip data from the travel survey is used in connection with these
networks and a system of computer programs to produce "network assignments'
is developed. These assignment procedures allow zonal trip interchange
data to be allocated to specific elements of the transportation system--
transit trips to various combinations of transit routes, auto trips to
various highway facilities, etc. Through these procedures and techniques,
it is possible to approximate the movement of people and vehicles between
various land activities on the existing transportation facilites.
The information available from the assignment techniques includes
vehicle miles of travel, average speeds on various components of the
network, types of trips on various segments of the transportation faci-
lities, vehicle and person trip ends by traffic zone, average trip length
in miles and time for various types of trips and modes of travel, and the
various area-to-area movements that result in specific volumes on indi-
vidual transportation facilities or combination of facilities.
b. Phase II: Analysis - The fundamental purpose of the second phase of
the transportation study is to develop procedures to project future travel
demands. The analysis is aimed at obtaining an understanding of the
fundamental characteristics of the travel data obtained in the first
phase. These characteristics are quantified and expressed in mathematical
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formulas that relate travel demand to the land use, land activity, and
transportation system characteristics. The analysis is focused on quanti-
fying the answers to specific questions, such as: What are the relation-
ships that exist within the transportation study area between the magni-
tude of trips generated by or attracted to each land activity, and the
intensity of that activity at each location? What effect does spatial
separation of certain land activities have on the number of trips made
between one portion of the study area and another? What unique patterns
exist in the present distribution of travel demands? How are these pat-
terns explained, and how will they relate to the transportation demands of
the future? How reliable and how stable are the mathematical formulations
used to develop travel demand estimations and project travel demands?
What factors influence the number of trips made within the area?
In general, the following types of mathematical models are developed
and calibrated in the larger transportation studies.
Land Activity Models - These models provide a technique for distri-
buting regional activity levels to small areas and subsequently to drive
other 1-and activity and socioeconomic data related to the activity dis-
tribution. Three general types of activity allocation models are in
current use. They are trend analyses, econometric, and probability-based
models. (See Appendix C for detailed discussion of these models.) It
should be noted that quantified land activity modeling as discussed in
Appendix C is applied in only a few urban areas. The projection of land
use and land activity has been developed using procedures that are sub-
stantially judgmental.
Trip Generation Models - These models provide a technique for formu-
lating the relationships between the trip generated in a traffic zone and
the characteristics of the zone such as land use and land activity mea-
sures. Many alternative techniques are used for trip generation. The two
most common techniques are multiple-regression analysis and cross-classi-
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fication analysis. The multiple-regression analysis is a statistical
technique in which multivariable equations are developed to relate land
activity measures within a zone to the number of trips by trip purpose
generated by the zone.
Cross-classification is a technique in which the tripmaking attri-
butes of persons or households by trip purpose can be estimated when the
changes in two or more other attributes of the person or household are
accounted for. In this technique a number of independent variables are
stratified into two or more groups creating a matrix. Observations on
the dependent variable are then allocated to the cells of the matrix,
based on the values of the independent variables. For example, total
person trips per dwelling unit could be developed based on the median
household income.
Trip Distribution Models - Once the zonal trip generation is devel-
oped, the trip distribution models are applied to predict the distribu-
tion of these trips among the zones within the study area. The three
most common trip distribution models are the growth factor technique, the
interviewing opportunities model, and the gravity model techniques. In
the growth factor technique, such as the Fratar method, an existing trip
distribution is modified by applying factors representing the projected
growth of each zone in an iterative process to the existing travel data
until the desired trip growth of each zone is reached. This technique
generally is used only in smaller and slowly growing areas.
The intervening opportunity model is a probability function based on
the premise that total travel time from a point is maximized, subject to
the condition that every destination point considered has a stated prob-
ability of being acceptable. More precisely, the opportunity model
states that the probability that a trip will terminate within some volume
of destination points is equal to the probability that this volume contains
an acceptable destination, times the probability that an acceptable
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destination closer to bhe origin of the trip has not been found. The
model operates on inputs concerning the total trips originating in a
zone, the total destinations in a zone, and empirically derived prob-
ability constant based on the average density of trip ends and the aver-
age trip length.
The gravity model is the most widely used of the three trip dis-
tribution techniques. It is based on the assumption that trips produced
at an origin and attracted to a destination are directly proportional to
the total trips produced at the origin, the total trip attraction at the
destination, an empirically derived impedance measure for interchange
travel between zones, and in some cases a socioeconomic adjustment factor.
Modal Split Models - These models disaggregate total person trips
into auto-driver trips, auto-passenger trips, and transit-passenger
trips. Three types of modal split models are commonly used: direct
transit and auto trip generation, trip-end modal split, and trip-inter-
change modal split. In the direct trip generation model, transit and
auto trips are developed directly from trip generation equations. The
trip-end modal split model uses the total person trips produced by the
trip generation equations and produces an estimate of the auto and tran-
sit trips prior to trip distribution. The trip-interchange modal split
models use the person-trip distribution from the trip distribution models.
c. Phase III: Projections and Plan Development - Using the techniques
described above the land use, land activity, economic activity, and
travel demand are projected to future years., These projections, or
forecasts of expected activity levels, form the basis for testing of
alternatives and evaluating results in light of the overall goals and
objectives of the communities in the study area. This procedure results
in the recommendation of the regional transportation program based on the
established objectives and standards of all of the communities contained
within the study area. Preparing alternative transportation plans calls
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for imagination and judgment as well as a deliberate attempt to arrange
the transportation facilities so that future transportation strategies
can be developed within the limitations of financial constraints and
community values.
Each of the alternatives tested must be evaluated in light of the
total developments of the area as well as the specific facilities and
their effect on their immediate environment. Existing and planned re-
newal and redevelopment areas, housing projects, new subdivisions, in-
dustrial districts, regional parks, open space, etc., must be taken into
account. The selected plan must be as compatible as possible, and must,
to the extent possible, promote other community goals and objectives,
including air quality, energy conservation, and mobility.
The final result of this phase of the planning study is a coordi-
nated and acceptable plan of action to meet the needs generated by the
forecasted land activity, land use, and traffic demand and to provide the
study area with the best solution to the transportation needs that will
exist in the future.
Projection of Land Use and Land Activity - In the plan development
and analysis process carried out in many metropolitan areas, multiple
land use and transportation plans are considered, while in others, trans-
portation alternatives are developed in relation to a single land use
plan.
In those studies in which only a single and use plan is used, the
first step in the projecting procedure is to estimate the future land use
and land activity for the entire study area. These projections are then
disaggregated so that the employment, population, and other land activity
measures are distributed into the subareas of the region.
Travel Demand Forecasts - The next step in the projecting procedure
is to convert the future land use and land activity into future travel
demand. This is done by applying the mathematical procedures developed
in the analysis phase to the projected land use and land activity infor-
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mation. The result of this procedure is a systematic and detailed fore-
cast of the location and magnitude of future travel demand throughout the
area. Once the future travel demand is established, it is studied in
relationship to the available transportation system in the area. In this
way, the location of future facilities and services is developed and
evaluated.
In the metropolitan areas where alternative comprehensive land use
and transportation plans are tested, the procedures for developing alter-
native land use and land activity vary greatly. In some studies various
land use and land activity concepts such as radial corridor development,
multitown (satellite towns) development, compact city, spread city,
linear city, etc., are selected as general land use and land activity
forms. Projections of future land use and land activity are developed
based on these concepts and various alternative transportation plans. In
some studies, the type and density of activity projected for a given area
is strongly influenced by the relative level of proposed transportation
facilities and service available to the area. In other studies, various
combinations of these approaches for developing alternative land use and
transportation plans are used.
Analysis of Alternatives - In addition to the variations in develop-
ing land use and land activity projections, several transportation alter-
native concepts are used in most studies to develop and test alternative
plans. These include transportation variations such as high-intensive
plans, freeway-intensive, radial systems, grid systems, minimum improve-
ment, maximum improvement, as well as various combinations of these
network concepts.
In the evaluation of each of the land use plans and transportation
alternatives, many types of procedures and techniques are emphasized. One
generalized procedure, common to almost all studies, involves the devel-
opment of future travel demands, the assignment of these travel demands
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to the transportation network, and the evaluation of the assigned volumes
relative to some performance measures.
In addition to the evaluation of the performance of a single land
use and/or transportation plan, comparisons of alternatives are also made
in most areas. In many studies, comparisons and evaluations to a no-
improvement alternatives, in which only the existing transportation
facilities and service are included in the network, are also made.
Performance measures used in these evaluations at both the regional
and subregional levels include total trips by persons and Vehicles by
mode and purpose; travel times and cost by mode and trip purpose; vehicle
miles of travel, and vehicle hours of travel; average speed by mode and
facility type; measures of system capacity relative to travel demand by
mode and facility type; trips to and from major subareas (such as the
CBD) by mode and trip purpose; and average length by mode and trip purpose.
Another type of system evaluation commonly used is an economic
analysis such as the benefit-cost analysis. In this type of analysis,
facility cost and transportation cost by both the public and private
sector are estimated. Comparisons are then made of the benefits derived
from decreased travel distance and travel time and the cost of providing
the proposed facilities and service.
Performance measures of accessibility provided by the highway and/or
transit system to various subareas as well as as general measures of
accessibility to population, employment, and other land use activity are
also developed by some studies. Many forms of analyses are developed in
various studies to evaluate the impact of various land use plans and
policy elements. Incorporated in many of the studies are evaluations of
the impact of various public policies regarding the transit systems,
parking facilities, sewer policies, open space, land use control for
commercial and industrial development, etc.
From the analysis of alternative land use and transportation plans,
one of the alternatives, or a new plan developed from several alternatives,
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is selected for implementation. The selected plan may apply to the short
range (5 years) to correlate with priority programs for funding and
planning at state and local levels; longer range plans are used to guide
development over time.
d. Phase IV: Continuing Planning and Implementation - Most of the 3-C
transportation studies are complete through the first three phases of the
study process and are now in the implementation and continuing planning
phase of the study. For these studies an "Operations Plan for Continuing
Urban Transportation Planning" has been prepared. Each of these plans
includes:
• An outline of the organizational structure for performing
continuing planning, including related committees
• An outline of the scope of the continuing planning, with a
breakdown of the functional and financial responsibilities of
all participating agencies
• A description of the surveillance methodology to be employed in
identifying changes in land development and travel demand,
including assignment of responsibility for providing inputs to
various models
• A description of the land use and travel projection procedures
to be utilized, including specific information required for the
various analyses
• A description of any work remaining to be completed on the ten
basic elements (PPM 50-9 paragraph 5) including a schedule for
completion of work. The ten basic elements are:
Economic factors affecting development
Population studies
Land use
Transportation facilities, including those for mass
transportation
Travel patterns
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Terminal and transfer facilities
Traffic control features
Zoning ordinances, subdivision regulations, building
codes, etc.
Financial resources
Social and community value factors
In the FHWA guidelines for the continuing planning process (Instruc-
tional Memorandum 50-4-68) five elements are identified:
Surveillance - includes studies of annual population growth, traffic
counts, transit usage, and changes in land development policy.
Reappraisal - is a three-level procedure.
Level 1, Routine Review, is intended to determine annually if changes
in urban development are in accordance with projections.
Level 2, Major Review, is usually conducted every five years; it
includes a check on the accuracy of the travel forecast process to simu-
late actual traffic.
Level 3, Plan Reevaluation, is a complete revaluation of land use
and transportation plans conducted at least every ten years. It includes
reassessment of goals and objectives of population and employment fore-
casts, an analysis of the networks, parking policy and transit, and a
restudy of finances for improvements and priority projects.
Service - includes supplying data to other agencies, assisting in
development of state and Federal needs estimates, and assistance to urban
agencies responsible for implementing portions of the plan.
Procedural Development - provides for update of techniques for
projection and plan development and for research in these areas.
Annual Report - is intended to serve as an informational document
for technicians, decision-makers, and citizens. It includes a quantita-
tive summary of all surveillance items as well as an assessment of the
process as described by the implementation program, a check on consistency
of development with the plan, and deviations from the plan.
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Implementation of the plan is carried out through the preparation
and adoption of priority programming and budgeting, and subsequently
through the design and construction phases of a project. Priority pro-
jects are defined, generally by the state department of transportation
(or the state highway department) and the local jurisdictions depending
on which is the implementing agency. These programs are based on recom-
mendations of the 3-C planning process. The criteria for designation of
priorities include design volumes, land activity, funding requirements,
etc.
In the short term, priority projects are placed in capital improve-
ments budgets submitted to state and local legislative bodies for funding.
These are generally annual budgets; they may be either cash flow or
appropriation budgets. The budget requirements are described in a full 5-
year program.
5. Data Sets and Formats
Many reports, technical memoranda and tabulations, and summaries of
data are produced through the 3-C planning process. Because of the dyna-
mic nature of the planning effort in many areas, problems can occur in
the evaluation of published reports and tabulations of data. In many
cases, detailed documentation of current practices and projections, which
may differ substantially from those previously documented, are either not
available or exist only in the form of technical memoranda with limited
distribution. Thus, efforts to utilize transportation planning data must
be accomplished through staff of the local 3-C planning agency.
a. Reports
Annual Report - Each of the 3-C agencies is required to prepare an
annual report as described above. This report contains a summary of the
current planning activity and the surveillance program as developed in
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the operations plan for the individual study. This report also contains
the 5-year improvement program for the study area.
The Operations Plan - This plan for each study in the continuing
phase describes the organizational structure, scope of the continuing
planning and the methodology and procedures used in the study. The
operations plan is revised when significant changes occur in the study
operations.
The Unified Work Program - This report is developed annually by 3-C
study areas and describes the allocation of funds for the planning acti-
vity.
The Action Plan - Each state has developed an action plan describing
the organizational structure and processes to be followed in the develop-
ment of Federal-aid projects from initial system planning through design.
Study Reports - In addition to numerous technical reports generated
by each study, several summary reports are typical to most studies:
t Base Year Findings Report - This report presents in a summarized
and graphic form the results of the data collection phase of
the study.
• Model Development Report - This report contains a description
of the development and validation of the models used in the
study.
• Forecast Report - This report contains a description of the
land use, land activity and travel forecast.
• Transportation Plan Report - This report describes the pro-
cedures used to develop and evaluate the various transportation
and land use alternatives, and the resulting plan or plans
developed from this analysis
Capital Improvements Plan - This is the short- and long-range dollar
budget for implementing each phase of the plan. It is from this budget,
when adopted, that state and local funds are allocated for transportation
projects on a priority basis.
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b. Computer and Other Data
Most of the 3-C studies have compiled the following types of data:
Existing and Projected Land Use and Land Activity Data by Traffic
Zone - In most studies, there is a tabulation of the base year data
described previously. These data are updated under the procedures des-
cribed for the operations plan. The projected data is generally devel-
oped for short-term projections and for the design year. The short-term
projection, a 5 to 10 year projection, and the long-term projection is for
15 to 20 years.
Transportation Facilities - Base inventories of the existing highway
and transit facility and travel demand are also upgraded annua" ly under
the continuing phase of the transportation study. This includes traffic
counts on highway facilities, patronage, and revenue data for the transit
system, and an update of the inventory of transportation facilities. In
addition to this information almost all studies have developed short-term
and long-term travel demand. These area travel demands, based on the
projected land use and land activity data, are assigned to future trans-
portation networks to provide approximations of the future demand for all
major transportation facilities. Data available from these procedures
includes zone-to-zone travel demand by trip purpose and mode, total
travel demand generated, vehicle miles and vehicle hours of travel by
facility type, total travel demand on each segment of the highway and
transit system, and travel speed on each segment of the highway network.
Travel demand may be defined in subareas, or districts, which are aggre-
gations of traffic zones.
This generalized discussion is intended to serve as a guide to those
who may be participating in air quality maintenance planning. It should
be recognized that in many urban areas the data required for air quality
maintenance planning may not be readily available, or will require re-
formatting, or even reanalysis. It may be expected that, over time, the
3-C process will include compatible inputs, analyses, and products that
can be used for comprehensive environmental planning.
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CHAPTER III
AIR QUALITY MAINTENANCE AND COMPREHENSIVE PLANNING
A. GENERAL APPROACH FOR CONSIDERING AIR QUALITY MAINTENANCE IN THE
COMPREHENSIVE PLANNING PROCESS
Land use patterns and their attendant activities have a major impact
upon the type and amount of air pollution generated over a region. To
the extent that land use can be associated with the discharge of pollutants,
it is necessary to plan future land use and transportation that is com-
patible with acceptable levels of air quality. Although comprehensive
planning has in the past been relatively insensitive to air quality
considerations, it is now incumbent upon the planning community to define
and implement the methodology, analytic tools, and standards that will be
considered simultaneously with other environmental constraints and direc-
tives for planning new development.
In order to accomplish the inclusion of the air quality maintenance
segment into the comprehensive plan, two areas must be explored: techni-
cal procedures for the incorporation of air quality as a constraint in
the planning process and procedures for ensuring or enforcing the mainte-
nance of air quality standards for specific projects. This latter require-
ment is discussed in the plan preparation guidelines of this series.
B. A PROCESS FOR EVALUATING THE IMPACTS OF LAND USE AND AIR
QUALITY PLANS OR POLICIES
In order to consider air quality in the plan development process,
some analytical process must be available to define the impact of alter-
native land use and transportation plans or policy changes on air quality.
In addition, the preparation of an air quality maintenance plan requires
the analysis of the impact of air pollution control strategies on land
use and transportation and its resultant impact on air quality.
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One conceptual process for relating land use and/or transportation
plans to air quality is described in Figure III-l. This approach is
suggested in addition to those discussed in Appendices A and B.* The
actual procedure to be applied in any AQMA will depend on the skill and
knowledge of personnel, the level of detail of the data base, the funding
available to complete the analysis, etc. The procedures used in the four
example cities, as discussed in another volume of this EPA guideline
series should also be considered.
The suggested process is iterative and could be applied at several
points in the development, evaluation, and implementation of air quality
maintenance plans as follows:
• Plan Development and Evaluation
Evaluation of the air quality or emissions impact of
existing land use and transportation plans.
Evaluation of the air quality or emissions impact of
alternative future land use and transportation plans under
different assumptions of control technology or energy
needs.
Evaluation of the impact of AQMP strategies, Transporta-
tion Control Plan (TCP) strategies, and other State Im-
plementation Plan (SIP) strategies on land use and trans-
portation requirements and the resultant air quality
impact.
• Plan Implementation
Suggest modifications to transportation plans, land use
plans, or SIP's at plan update or critical review.
Suggest an emissions allocation procedure based upon the
estimate of emissions.
* Environmental Research and Technology, Inc., "A Guide for Considering
Air Quality in Urban Planning," (Lexington, Mass.: March 1974).
54
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Figure III-l
THE AIR QUALITY IMPACT-LAND USE PLANNING PROCESS
STEP 1—Establish the Air Quality Baseline
• Existing Concentrations
• Annual Equivalent to Standards
STEP 2—Define the Tolerance of the Planning Area to
Additional Pollutant Emissions
Simplified Dispersion Model
STEP 3—Set Constraints on Industry and Transportation
Industrial Types and Amount
Transportation
Other Environmental Constraints
STEP 4--Generate Comprehensive Land Use Plan
o Major Sources
• Non-Industrial non-transportation land uses
STEP~5—Evaluate Air Quality Impact
t Emissions
• Meteorological Data
• Air Quality Standards
Source: Environmental Research and Technology, Inc., "A Guide for Con-
sidering Air Quality in Urban Planning," (Lexington, Mass:
March 1974).
55
-------
The five steps indicated in Figure III-l are summarized briefly:
Step 1. Establish Air Quality Baseline
The first step is to define existing regional air pollutant concen-
trations to determine an air quality baseline for the planning area.
State air pollution agencies are the primary source for such data. If
the existing air quality data is insufficient to represent both the time
periods specified in the air quality standards and the spatial distribu-
tion of concentrations, additional data should be obtained.
Step 2. Define the Tolerance of the Planning Area to Additional
Pollutant Emissions
The allowable increase in air pollutant concentrations should be
determined by comparing the air quality baseline to the air quality
standards. Allowable concentration increases must then be related to
corresponding allowable increases in pollutant emissions. This is ac-
complished by application of an atmospheric dispersion model. Simplified
dispersion models which can be applied are presented in the analysis
volume of this Guidelines series.
Step 3. Set Constraints on Industry and Transportation
Based on the tolerance to additional emissions, constraints on the
distribution and amount of transportation and industrial sources can be
determined. The possible alternatives should be examined against other
planning constraints and criteria such as water quality and economic
growth at this point. Background information and procedural guidelines
for quantifying generalized relationships between industry and transpor-
tation and their emissions are presented in the EPA Guidelines series and
the ERT document.
56
-------
Step 4. Generate Comprehensive Land Use Plan
Having defined one or more possible alternatives, the planner must
distribute these sources within the planning area. This is accomplished
by a detailed, quantified land activity analysis, or by using less sophis-
ticated quantification procedures such as the land use portion of the
3-C plan, or making activity estimates based on a land use map. These
are further described in the analysis section of these guidelines. Since
this requires the placement of specific land uses within the area, the
spatial contours of existing pollutant concentrations as well as the
dispersion patterns of anticipated emissions must be considered if local
violations of the standards are to be prevented. Generalized dispersion
characteristics are presented in the ERT document. In addition, the
planner may wish to use a numerical simulation model specific to his
planning area. An air pollution specialist would be required to perform
such modeling.
Step 5. Evaluate Air Quality Impacjb
A detailed air quality impact analysis of the comprehensive plan is
a final step in the process. This is primarily due to the generalized
nature of the data used in the selection process. However, by specifying
land uses in Step 4, the planner has generated sufficiently detailed
information to perform more extensive analysis.
As described, the land use and transportation plans or policies must
provide detailed information relevant to emissions that would result from
the plan or policy before it can be translated into the impact on air
quality. The following section briefly describes the information required
to relate land use to air quality and discusses the availability of
techniques to provide this information.
57
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C. INFORMATION AND ORGANIZATION REQUIRED TO RELATE LAND USE TO
EMISSIONS AND AIR QUALITY
A generalized flow in information required to relate land use to air
quality is given in Figure III-2. As can be seen, the land use or trans-
portation plans do not currently provide the emissions data needed to esti-
mate air quality impact as required by the process shown in Figure III-l.
If air quality considerations were a determining factor in the land use
planning process, basic emissions data would be collected in conjunction
with the basic inventory requirements of a land use or transportation
plan.
The content and form of current emissions inventories is mainly a
function of modeling requirements. Therefore, one or more intermediate
modeling or conversion techniques is needed to translate the land use
activity data into the required emissions inventories.
Steps 1 and 2. Generation of Activity Information
The flow diagram indicates that the land use and transportation plan
must first be quantified to provide data relevant to the "intensity" of
use in the specified land use category. This has been done historically
by a combination of economic analyses, surveys (origin-destination studies),
and application of activity allocation models. Land activity allocation
models have been developed within a wide range of complexity and data
base requirements. A brief annotated bibliography of activity allocation
models is given in Appendix C to this report. Where such models have
been executed, the results can be useful in providing the input necessary
for the development of the detailed emissions inventory.
In the Hackensack Meadowlands Air Pollution Study (see Appendix B),
estimated emission rates for various land use categories in the areas
were developed (see Table III-l). These emission rates are very limited
in accuracy because of the limited and generalized land use and activity
data upon which they are based. However, they may be useful to planners
58
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FIGURE III-2
INFORMATION ACCESS REQUIREMENTS OF A PROCESS TO
RELATE LAND USE AND TRANSPORTATION PLANS TO AIR QUALITY
STEP
Models or Techniques
Information
Land Use Plans and
Transportation Plans
(Activity Allocation,
Surveys, Economic
Studies, etc.)
Conversion Factors
Emission Models
Emission Factors
Existing Inventories
Emissions Allocation
or
Disaggregation Model
Air Quality Model
Evaluation Model
or Criteria
k.
k.
h
*-
k.
Land Use/Activity
T r ansportation
Network
^
r
Activity Parameters:
Fuel Use/
Demand Data,
Process Rates, etc.
^
r
Emissions Inventory
Area-Wide Emissions
by Pollutants by
Time Period
i
r
Emissions on a
Sub-Area Basis
as Required by
Air Quality Model(s)
T
r
Air Quality
Regional ar
i
r
Air Quality Impact
•*
Modify Design, Suggest Plan Revision,
o
U
05
fl
O
tn
en
W
(D
tn
«|H
0)
K
59
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TABLE III-l
SUMMARY OF ESTIMATED 1990 ANNUAL EMISSION RATES
FOR HACKENSACK MEADOWLANDS LAND USE CATEGORIES
Pollutant Emissions
(1 fa/year/acre)
Land Use Category
Residential
10 Dwelling units/acre
20 Dwelling units/acre
30 Dwelling units/acre
50 Dwelling units/acre
80 Dwelling units/acre
Commercial & Industrial
Commercial
Manufacturing
Light
Heavy
Research
Distribution
Special Use
Airport*
Transport Center
Cultural Center
Open Space
Other**
Highway (lb/106 VMT)
Parking lots (lb/103 hrs idling)
TSP
25
180
180
250
200
60
1100
5400
2
60
60
100
180
45
0
S02 CO
1 35
120 4
120 4
160 5
140 4
45 1
1100 10
5400 60
15 1
45 1
45 1
1000 3000
130 2
35 1
0 0
HC
12
54
54
75
63
12
140
900
5
12
12
350
36
9
0
NO
X
7
85
85
120
100
95
850
5400
35
95
95
100
300
70
0
Emission Factors
700
4
400 11000
4 12
1000
3
* Assumes 400,000 flights/year from Teterboro Airport, and 700
** Activities are not specified on
Source: The Hackensack Meadowlands
basis
Air
of emissions/uni
Pollution Study,
t area.
Summary
1500
1
acre area
Report,
Environmental Research and Technology, October 1973.
60
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as a rapid evaluation technique for gross planning estimates at the early
stages of plan design. This would eliminate the need for Step 2, Conver-
sion Factors. It is recognized that the emission rates in this table are
highly specific to the Hackensack planning district, and it would be
necessary to create such a table specific to each area of concern. An
attempt was made in the "Air Pollution/Land Use Planning Project" (see
Appendix B) to prepare such a table which would be generally applicable;
however, the results indicate that these factors cannot be generalized.
If factors can be developed based on local considerations as in Table III-l,
or by similar techniques, the emission factors for the plan area can be
developed for each specific pollutant and land use category.
Step 3. Development of Emissions Inventory
The projected regional emissions inventory can be developed at this
point from the information generated in Steps 1 and 2. This can be
accomplished by applying emissions models to the activity parameters
generated in Step 2 or emission factors to the activity categories as
shown in Table III-l.
Step 4. Emissions Allocation
In this step the emissions inventory is allocated to a subarea level
required to be input to an air quality model. If a quantified land use
or activity allocation model has been used to develop emissions in Step 3,
the emissions data will already be at a level of spatial distribution
sufficient for input to most air quality models.
If, however, the emissions inventory was calculated from regionwide
or countywide land use and transportation data the emissions will not be
sufficiently disaggregated to support most air quality diffusion models.
61
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Step 5. Air Quality Model
Many air quality models are currently in use in specific areas or
studies. These models range from the proportional models such as "roll-
back" to highly complex models that are related to fundamental theory.
The utility of these air quality models is dependent on the specific
application. The guideline document prepared by EPA in this series which
discusses air quality models for air quality maintenance plans can be
consulted for further information. As the model complexity or level of
analysis requirements increase, the concurrent emissions inventory
requirements (Step 3) increase.
A rough estimation of the total regional (plan area) air quality im-
pact of the given plan can be made by using a simple proportional model
such as "roll-back" to relate emissions to air quality. However, this
procedure gives no indication of the resultant spatial distribution of
the pollutants within the region (plan area). An air quality planner
using a regionwide roll-back technique to evaluate air quality impact of
a proposed land use plan could conceivably allocate the pollutant sources
in such a manner as to violate the air quality standards within a subareas,
although the regional air quality level would still appear to be within
the air quality standards. In order to locate and avoid such "hot-spot"
problems in the plan, the emissions data must be disaggregated to the
level of detail required to identify such problem areas.
If an air quality model is being used to evaluate the effectiveness
of a land use control strategy, the data allocation procedure and air
quality model used must also be representative of the level of detail
required by the strategy definition. For example, a land use strategy
that requires control of the location of specific sources would require a
site-specific emissions data allocation system.
Ideally, quantified land use should provide the emissions inventory
to meet the scale requirements of the air quality model. If such detailed
land use and activity data are prepared, Step 4 would become unnecessary.
62
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Step 6. Evaluation
The air quality impact described by the output of the air quality
model must be evaluated against the National Ambient Air Quality Stan-
dards. Other evaluation criteria might include the exposure of sensitive
receptors to pollutant concentrations.
D. ANALYTICAL TECHNIQUES REQUIRED TO RELATE LAND USE AND TRANSPORTATION
PLANS TO AIR QUALITY
It is apparent from the previous discussion that a community-
specific analytical process must be developed to relate land use or
transportation plans to air quality. The process would consist of all
the analytical techniques or models required to provide the information
needed to relate comprehensive planning decisions to their impact on air
quality, and air quality planning decisions to their impact on land use
and activity. The process should also provide information and guidance
for the planner, local legislative bodies, and the public so that they
might clearly perceive the air quality impact of their planning decisions.
The process developed to relate land use to air quality must operate
at two levels:
• First, it must be able to relate the impact of the local plan-
ning decision on the subarea land use and activity, and result-
ant air quality.
• Second, it must be able to relate this subarea or project level
decision to its impact on the total regionwide (AQMA) air
quality.
In addition, the process developed should have the following charac-
teristics:
• It must be specific to the AQMA or planning area in order to
fully utilize the information resulting from the 3-C or land
use plan.
• It must relate to other planning efforts—environmental, socio-
economic, etc.
63
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• It should provide useful and reliable information to assist in
the formulation of policy and administrative guidelines.
• It should provide relevant information on subarea (i.e., county
or planning district) issues.
0 It should address pollutants of concern.
0 It should incorporate unique terrain, and meteorological fea-
tures, that may affect ambient air quality.
0 It should be flexible and be able to incorporate the state-of-
the-art in economic projections, land use models, emissions
models, air quality models, techniques for quantifying impact,
new source control technology, etc.
0 It should provide information in a form that can be simply
communicated to officials, citizen groups, and other units.
Development of a sound data base and detailed quantification of
regional land use and transportation plans should be considered as an
integral part of this process development.
64
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SELECTED REFERENCES
Advisory Committee on Highways and Air Quality. Highways and Air Quality.
Washington, D.C.: Highway Research Board, 1973.
Anderson, Frederick R. NEPA in the Courts: A Legal Analysis of the
National Environmental Policy Act. Baltimore, Maryland: Resources
for the Future, 1973.
Bellomo, Salvatore J. "Providing for Air Quality and Urban Mobility,"
Paper presented at the Fifth Annual Summer Meeting of the Highway
Research Board, Madison, Wisconsin, July 31-August 2, 1972.
Bellomo, Salvatore J., Dial, Robert B., and Voorhees, Alan M. Factors,
Trends, and Guidelines Related to Trip Length, National Cooperative
Highway Research Program Report No. 89 Washington, D.C.: Highway
Research Board, 1970.
Bosselman, Fred and Callies, David. The Quiet Revolution in Land Use
Control, Washington, D.C.: U.S. Government Printing Office, 1971.
Branch, Melville C. and Leong, E.Y. Air Pollution and City Planning.
Los Angeles, California: University of California, 1972.
Bunyard, F.L. and Williams, J.D. "Interstate Air Pollution Study—
St. Louis Area Air Pollutant Emissions Related to Actual Land Use,"
A Paper presented at the 59th Annual Meeting of the Air Pollution
Control Association, San Francisco, California, June 1966.
Capitol Region Planning Agency. Air Pollution Study of the Capital
Region. Hartford, Connecticut: TRC Service Corporation, 1967.
Chapin, Stuart F. Urban Land Use Planning. Urbana, Illinois:
University of Illinois Press, 1965, 2nd ed.
Clawson, Marion, ed. Modernizing Urban Land Policy, Baltimore:
Johns Hopkins University Press, 1973.
Clean Air Amendments of 1970, Statutes at Large, Vol. 81 (1970). U.S. Code;
Vol. 42 (1970).
Cohen, A.S. and Hurter, A.P. Urban Evaluation and Air Pollution. Air
Pollution Control Association, June 1970.
65
-------
Cross, Frank L., Or. and Davis, W.K. "Estimation of Environmental
Impact from Point Source Air Pollution Emissions," Paper presented
at Northeast Regional Science Association conference, University
Park, Pennsylvania, April 14-16, 1972.
Dalbertdt, Water F. and Ludwig, F.L. Validation and Applications of an
Urban Diffusion Model for Vehicular Pollutants. Menlo Park,
California: Stanford Research Institute, 1972.
Demarrais, G.A. Meteorology for Land Development Planning in the Tulsa
Metropolitan Area. Cincinnati, Ohio: Public Health Service, 1961.
Effenberger, Ernst. "Air Pollution and City Planning." Z. Praventiv-
medizin, XI. (November-December 1966), 601-621.
Environmental Research and Technology, Inc. "Guidelines for Consideration
of Air Quality in Urban Planning." Lexington, Massachusetts, March
1974.
GCA Technology Division and TRW, Inc. Transportation Controls to Reduce
Motor Vehicle Emissions in Major Metropolitan Areas. Research
Triangle Park, North Carolina: United States Environmental Protec-
tion Agency, 1972.
Goodman, William T., and Fruend, Eric C., ed. Principles and Practice
of Urban Planning. Washington, D.C.: International City Manage-
ment Association, 1968.
Goodrich, John C. and Willis, Byron H. "A Methodology for Determining
Emissions from Land Use Planning Data," Paper presented at the
65th Annual Meeting of the Air Pollution Control Association,
Miami, Florida, June 18-20, 1972.
Hagevik, George, ed. The Relationship of Land Use and Transportation
Planning to Air Quality Management. New Brunswick, New Jersey:
Rutgers University Press, May 1972.
Hillsborough County Planning Commission. Land Use Pjanning Air Pollution
Control. Tampa, Florida: Hillsborough County Planning Commission,
1973.
Institute of Public Administration and Teknekron, Inc. Evaluating
Transportation Controls to Reduce Motor Vehicle^Emissions in Major
Metropolitan Areas. Research Triangle Park, North Carolina: U.S.
Environmental Protection Agency, 1972.
66
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Kaiser, E.J., et. al. Promoting Environmental Quality Through Urban
Planning and Controls. Washington, D.C.: U.S. Environmental
Protection Agency, 1973.
Kennedy, Allen S., Cohen, Alan S., Croke, E.J., Croke, K. G., Stark, J.
and Hurter, A.D. Air Pollution—Land Use Planning Project—Phase I.
Final Report. Chicago, Illinois: Argonne National Laboratory,
Center for Environmental Studies, November 1971.
Krueckenberg, Donald A. "State Environmental Planning: Requirements
vs. Behavior," Journal of the American Institute of Planners,
XXXVIII, No. 7. (November 1972), pp. 392-396.
Kurtzweg, J.A. and Weig, D.W. "Determining Air Pollutant Emissions from
Transportation Systems," Paper presented at the meeting of the
Association for Computing Machinery, New York, New York, October
1969.
Larsen, Ralph I. A Mathematical Model for Relating Air Quality Measure-
ments to Air Quality Standards. Washington, D.C.: U.S. Government
Printing Office, 1971.
Leaderer, Brian P. and Sovas, Gregory H. "Allocation and Projection of
Residential and Commercial Emissions Through Use of the LUNR Inven-
tory." Paper presented at the 65th Annual Meeting of the Air
Pollution Association, Miami, Florida, June 18-22, 1972.
Leavitt, Jack, M. "Meteorological Considerations in Air Quality
Planning." Air Pollution Control Assocation Journal, X (June 1960),
pp. 246-250.
Meshenberg, Michael J. Air Zoning: An Application of Air Resources
Management. Chicago, Illinois: American Society of Planning
Officials, July 1966.
Northeast Illinois Planning Commission. Managing the Air Resources
in Northeast Illinois. Chicago, Illinois: Northeast Illinois
Planning Commission, 1967.
Office of Management and Budget, Standard Industrial Classification
Manual. Washington, D.C.: U.S. Government Printing Office, 1972.
67
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Peat, Marwick, Mitchell & Co. A Review of Operational Urban Transportation
Planning Models, prepared for U.S. Department of Transportation,
Transportation Systems Center, Cambridge, Massachusetts, April
1973.
Pelle, William J., Jr. "Bibliography on the Planning Aspects of Air
Pollution Control," Washington, D.C., 1964. (mimeographed).
Rydell, C. Peter and Collins, D. "Air Pollution and Optimal Urban
Form." Paper presented at the 60th Annual Meeting of the Air
Pollution Control Association, Cleveland, Ohio, June 11-16, 1967.
Rydell, C.P. and Schwarz, G. "Air Pollution and Urban Form: A Review
of Current Literature." Journal of the American Institute of
Planners. March 1968.
Stern, Arthur C., ed. Air Pollution. Vol. I: Air Pollution and Its
Effects. New York: Academic Press, 1968.
Studholme, Edward Dickinson. "Prospective Effects of Motor Vehicle
Traffic on a Portion of the Urban Interstate Highway System—An
Environmental Planning Analysis." Unpublished Master's Thesis, The
George Washington University, 1972.
The Urban Land Institute. The Community Builders Handbook. Washington,
D.C.: Urban Land Institute, 1968.
U.S. Department of Transportation, Federal Highway Administration.
Urban Transportation Planning, General Information. Washington,
D.C., March 1972.
. Urban Origin-Destination Surveys, Washington,
D.C., 1973.
. Guidelines for Trip Generation Analysis, June
1967.
. The Role of Economic Studies in Urban Transportation
Planning, August 1965.
. Population Forecasting Methods, June 1964.
68
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U.S. Environmental Protection Agency. "Maintenance of National Ambient
Air Quality Standards." Federal Register. Vol. 38, No. 116, June 18,
1973, 15834-15837.
_. "Preparation, Adoption and Submittal of Implementation
Plans." Federal Register, Vol. 38, No. 74, April 18, 1973, 9599-
9601.
"Prevention of Significant Air Quality Deterioration."
Federal Register, Vol. 38, No. 135, July 16, 1973, 18986-19000.
"Requirements for Preparation, Adoption, and Submittal
of Implementation Plans.11 Federal Register, Vol. 36, No. 158,
August 14, 1971, 15486-15506.
VanNest, William J. and Hagevik, George H. Air Pollution and Urban
Planning: A Selective Annotated Bibliography. Monticello, Illi-
nois: Council of Planning Librarians, February 1972.
Voorhees, Alan M. and Associates, Inc. A Guide for Reducing Air Pollution
through Urban Planning, prepared for U.S. Environmental Protection
Agency. McLean, Virginia, 1972.
Voorhees, Alan M., Barnes, Charles F. Jr., and Coleman, Francis. Traffic
Patterns and Land Use Alternatives. Presented at Highway Research
Board 41st Annual Meeting.
Voorhees, Alan M. Practices and Trends in Transportation Planning.
Presented at the Highway Management Institute, March 1969.
Williams, James D. and Edminsten, Norman G. An Air Resource Management
Plan for the Nashville Metropolitan Area. Washington, D.C.: U.S.
Department of Health, Education and Welfare, September 1965.
Willis, Byron H. "The Hackensack Meadow!ands Air Pollution Study Sum-
mary Report." Submitted to the State of New Jersey Department of
Environmental Protection by Environmental Research and Technology,
Inc., August 1972.
Willis, Byron H., Gaut, Norman E., and Newman, Elliot. "AQUIP--An
Air Quality Evaluation System for the Planning Community," Paper
presented at the 64th Annual Meeting of the Air Pollution Control
Association, Atlantic City, New Jersey, June 27-July 2, 1971.
Willis, Byron H. and Mahoney, J.R. "Planning for Air Quality."
Paper presented at Confer-In '72 of the American Institute of
Planners, Boston, Massachusetts, October 1972.
69
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APPENDIX A
REVIEW OF THE STATE-OF-THE-ART FOR QUANTIFYING THE
RELATIONSHIP OF LAND USE AND TRANSPORTATION PLANS TO AIR QUALITY
-------
-------
REVIEW OF THE STATE-OF-THE-ART FOR QUANTIFYING THE
RELATIONSHIP OF LAND USE AND TRANSPORTATION PLANS TO AIR QUALITY
A. REVIEW OF RELATED STUDIES
If the process for relating land use and transportation plans to
air quality is to be used to prepare or evaluate the air quality mainte-
nance plans, all of the techniques and data required to provide the
information described in Chapter III must be available and generally
applicable. A review of several studies or models that have attempted
to relate land use and/or transportation plans to air quality was per-
formed to determine the utility of the study techniques or results to
the preparation of air quality maintenance plans.
An analysis of each of the following studies is given in Appendix B
of this document. In general, no generally applicable model or tech-
nique is available that will meet all of the information requirements
discussed below.. The models or studies listed below could serve as a
core to a community specific process or model. However, all such models
require extensive data bases which are not generally available.
1. The Hackensack Meadow!ands Air Pollution Study
Developed by Environmental Research and Technology, Inc., this
study provides a general methodology for considering air pollution in
the formulation and evaluation of alternative urban plans and applies
the methodology to alternatives developed for the New Jersey Meadowlands
area. The Air Quality for Urban Industrial Planning (AQUIP) model was
developed; this model uses a set of submodels requiring detailed data
for land use, emission factors, meteorology and ambient air quality.
A-l
-------
2. The Air Pollution/Land Use Planning Project
Completed by the Argonne National Laboratory, the objective; of this
study was to investigate the utility of various land use parameters in
describing the air quality impacts of land use plans, using the Chicago
region as a test. The tests were made for manufacturing and residential/
commercial land uses.
3. Guidelines for Relating Air Pollution Control to Land Use and
Transportation Planning in the State of California
These guidelines were developed by the firm of Livingston and
Blaney. The purpose was to integrate the goal of achieving and main-
taining air quality with the land use and transportation planning pro-
cess in California metropolitan regions. The primary concept is one of
allocating allowable emissions to subareas within air basins.
4. The Transportation and Air Shed Simulation Model (TASSIM)
The study, developed at Harvard University, was designed to develop
a model that would integrate existing urban transportation models,
vehicle emissions factors, and a simple air diffusion model to analyze
air quality effects of various transportation policies. The model was
applied and calibrated in the Boston area, using a district level "spider"
network, representing the average characteristics of the facilities
represented by the network.
5. The Baltimore Regional Environmental Impact Study (BREIS)
An evaluation of the environmental impacts of the proposed urban
interstate highway system in the City of Baltimore was the purpose of
this study. All environmental analyses, including air quality, were
performed on a regional basis. A quantified land use model and travel
A-2
-------
simulation of seven alternative land use and transportation policies
provided the base for examination of impacts. The study was conducted
by Alan M. Voorhees and Associates, Inc. for the Interstate Division for
Baltimore City.
B. SUMMARY AND CONCLUSIONS
The review of the studies and methodologies listed above, and the
techniques described suggest the following conclusions regarding the
state-of-the-art in relating land use to air quality and its application
to air quality maintenance planning:
1. General Conclusions
a. Land Use Data Base -- Land use can be quantified; however, the
available techniques require detailed area-specific data bases.
b. Converting Land Use and Activity Data to Pollutant Emissions --
Procedures do exist for the conversion of detailed land use and activity
data to pollutant emissions. However, the procedures are specific to
the study area for which they have been generated and the results imply
that these procedures would need to be developed on an area-specific
basis.
c. Disaggregating Pollutant Emissions Data -- Data allocation pro-
cedures do not exist for disaggregating pollutant emissions data.
However, the disaggregation of projected (long-term) pollutant emissions
is dependent upon detailed land use and activity data that may not be
available.
A-3
-------
d. Long-Term Air Quality Impact of Land Use — Mathematical models do
exist to relate emissions data to air quality or concentrations. In
order to determine the long-term impact of land use on air quality, the
procedures referenced in paragraph b above must be available to convert
land use data to pollutant emissions data for use in the air quality
models.
2. Emissions Calculations
Techniques are available to calculate emissions given detailed
process data for each source. Techniques are not readily available or
generally applicable for converting land use or activity data directly
to the process data necessary for emissions calculations.
3_. Emissions Projections
a.. Short-term Projection Techniques -- Short-term (1 to 5 years)
emissions projections techniques assume little or no change in past
trends. Application of any of these techniques requires careful consid-
eration of the assumptions and generalities used to simplify the tech-
niques r order to interpret the results.
b_. Long-term Projection Techniques Regional Totals -- Long-term emis-
sions projection techniques are available for projecting regionwide
emission totals, given a detailed existing emissions inventory and
reasonable regional growth factors. However, existing long-term growth
factors are not accurate indicators of the change in emissions and
should only be used as "indicators" of a possible problem.
c^. Long-term Projection for Transportation Network — Long-term pro-
jection techniques for traffic and transportation network data are
A-4
-------
available that give the geographic detail necessary to show significant
carbon monoxide problem areas within an AQMA due to these mobile sources.
However, these techniques are very costly to implement and require
detailed data base development that may include land use and activity
projections (Land use and activity projection models are referenced in
Appendix C).
d. Long-term Projection Techniques for Stationary Sources -- Long-term
emissions projection for small areas (sub-county) for stationary sources
(other than power plants) is dependent upon detailed knowledge of the
future location of specific sources. This specific data is not currently
available. Assumptions can be made to estimate the probable location of
future stationary sources within the AQMA; however, emissions projec-
tions based on these assumptions would not be sufficiently accurate to
make subarea planning decisions without careful surveillance and evalu-
ation of these assumptions as new information becomes available. These
emissions projections could be used to indicate possible or "most pro-
bable" problem areas.
4. Air Quality Diffusion Models
a. Diffusion Models for Projecting Primary Pollutants — Diffusion
models are currently available to project carbon monoxide (CO), total
suspended particulates (TSP), and sulfur dioxide (S02) for any geogra-
phic levels of detail for which emissions data are available. The
accuracy of these projections is dependent upon (1) the accuracy of the
emissions data, ambient air quality, and meteorological data used to
calibrate and validate the given model and (2) the degree to which the
area topographic and meteorological characteristics fit the model
assumptions.
A-5
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b. Diffusion Models Unavailable for Secondary Pollutants — Diffu-
sion models are not currently available to represent the air quality
concentrations of any of the secondary pollutants such as reactive
hydrocarbons (HC), nitrogen oxides (NO ) and oxidants (0 ).
X X
The state-of-the-art in emissions projections and air quality
projections are summarized in Tables A-l and A-2, respectively. It is
noted that microscale emissions and air quality projection techniques
are dependent on the ability to project growth at that level of detail,
A-6
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TABLE A-l
STATE-OF-THE ART SUMMARY
EMISSIONS PROJECTIONS TECHNIQUES
Level of Detail or Geographic Scale
AQMA
Microscale Subarea (or regional)
Pollutant-Source
CO-Mobile
CO-Stationary
HC-Mobile
HC-Stationary
NO -Mobile
X
NO -Stationary
X
TSP-A11
S02-A11
N
X
X
X
X
X
X
X
X
s
X
X
X
7
X
?
7
7
L
7
7
7
0
7
0
0
0
N
X
X
X
X
X
X
X
X
s
X
X
X
X
X
X
X
X
L
X
?
X
?
7
7
7
7
N
X
X
X
X
X
X
X
X
s
X
X
X
X
X
X
X
X
L
X
X
X
X
X
X
X
X
N--Now (1975)
S—Short term (to 1980)
L--Long term (to 1995 or beyond)
o--Not available
?--dependent on detailed
data base projection
x--currently available
A-7
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TABLE A-2
STATE-OF-THE ART SUMMARY
AIR QUALITY PROJECTION TECHNIQUES
Level
of Detail
Microscale
Pollutant
CO
HC
NO
X
0
X
TSP
S00
N
X3
0
0
0
X
X
s
X3
0
0
0
X
X
L
X3
0
0
0
?
?
or Geographic Scale
Subarea
N
X2
0
0
0
X
X
S
X2
0
0
0
X
X
L
?
0
0
0
?
?
(or
N
X2
X1
X1
X1
X
X
AQMA
regional )
S
X2
X1
X1
X1
X
X
L
X2
X1
X1
X1
X
X
Proportional models, i.e., roll back or roll forward
2Subarea and microscale models--statistical models (including Gaussian
models), climatological models, etc.
3Microscale C0--Line source models, etc., dependent on traffic assign-
ment projection data.
N—Now (1975)
S—Short term (to 1980)
L--Long term (to 1995 or beyond)
0--Not now available
?--Dependent on data base availability
X--Currently available
A-8
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APPENDIX B
REVIEW OF SELECTED STUDIES RELATING
LAND USE AND TRANSPORTATION TO AIR QUALITY
-------
-------
REVIEW OF SELECTED STUDIES
RELATING LAND USE AND TRANSPORTATION
TO AIR QUALITY
I. THE HACKENSACK MEADOWLANDS AIR POLLUTION STUDY -- ENVIRONMENTAL
RESEARCH AND TECHNOLOGY, OCTOBER 1973.
A. Study Purpose and Scope
The purpose of this study was (1) to develop a general methodology
for considering air pollution in the formulation and evaluation of
alternative urban plans; and (2) to apply this methodology to the planning
alternatives developed for the New Jersey Hackensack Meadowlands District.
In addition, a planning guidelines document was produced to enable urban
planners to introduce air pollution considerations into the planning
process.
B. Analytic Techniques
The Air Quality for Urban and Industrial Planning (AQUIP) System
developed and applied in this study consists of a set of submodels or
routines that perform the following tasks:
• Input data descriptive of the land use or transportation plan
is prepared.
• These data are converted into pollutant emissions data.
0 Mean ambient pollutant concentrations within the area of
interest are predicted and displayed.
• The plan, with respect to other plans through analysis of air
quality contours and the computation of quantitative measures
of impact, is evaluated and ranked.
Utilizing these submodels and techniques, the following can be
evaluated: (1) the compliance with ambient air quality standards, (2)
the impact of regional air quality levels, (3) the degree of impact on
B-l
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specific receptors or land use categories that are especially sensitive
to the effects of pollutants, and (4) an indication of ways to modify
the plan(s) to improve air quality.
LANTRAN is the submodel that processes the land-use and transpor-
tation data. The data are independent of grid size and land use is
allocated by geographic coordinates and land use zones. Activities are
designated as point source, line source, or area source generators for
input to the dispersion model. Land use activity and intensity data are
converted to emissions using a set of conversion factors, emission
factors, and activity parameters based on data specific to the Hackensack
plan. A set of default parameters was also developed (specific to
Hackensack data) for use when data is missing or incomplete. The air
quality dispersion model used (MARTIK) to convert these emissions to air
quality is a modification of Martin and Tikvart* as used in the Air
Quality Display Model (AQDM). The modifications were made to improve
accuracy and to treat line sources directly. Approximation techniques
were used to save computer time. The SYMAP software is used to display
the model output; this displays concentrations as intensity shadings
across the area of interest.
The air quality impact subroutine then performs the following
comparisons on a pollutant-specific basis based on the output from
MARTIK:
• Compare maximum concentrations to ambient air quality stan-
dards (AAQS).
• Determine percentage influence of background concentration of
total air quality within each plan.
*
D.O. Martin and J.A. Tikvart, "A General Atmospheric Diffusion
Model for Estimating the Effects of Air Quality of One or More Sources,1
APCA paper 68-148, Presented at 61st Annual APCA Meeting, St. Paul,
Minnesota, June 1968.
B-2
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• Determine the "average" regional air quality.
t Determine the "average" exposure of critical receptors and
land use categories to pollutant concentrations for the average
or worst meteorological conditions.
C. Model Application
The sample analysis was performed for the Hackensack Meadowlands
Planning District, a four by eight mile area near the densely developed
lower Manhattan area. Four plan alternatives for 1990 were evaluated
and ranked. The pollutants evaluated were TSP, S02, CO, HC, and N0x for
annual, summer, and winter averages. The analysis was for regional
impact only (microscale impacts were beyond the scope). The sample
analyses concluded that:
• The background concentration contribution for the Hackensack
area was so significant that land use planning on a regional
scale would be ineffective for abatement of regional air
pollution levels.
• The analysis of impact of alternatives showed significant
differences among spatial patterns due to:
Percent mix of land use
Relative location of land use activities
Relative intensity of land use activities
The observed spatial differences were especially sensitive to
the percent mix of manufacturing and transportation related
land use.
t Percentage open-space did not have a significant impact on
regional air quality.
0. Conclusions and Recommendations
The application results were evaluated and a guidelines document
was prepared that can be "generally applied to the land use and transpor-
tation planning process for the consideration of air pollution" in
ranking alternative plans. The guidelines should be applied to other
B-3
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planning situations only for consideration of regional scale air quality.
Detailed analysis would require the application of the complete AQUIP
system and the development of the associated detailed data bases.
Some general conclusions resulting from the analysis are:
0 It is important to evaluate and rank plans on the basis of
pollutant concentration rather than emissions because:
Air quality standards are related to concentration levels.
Meteorological conditions are critical in determining
capacity of a region to assimilate local source emissions
(i.e., to determine conditions under which planned land
use developments will exceed or comply with AAQS).
Meteorology is critical in determining levels of back-
ground pollutant concentrations transported into and out
of the planning region.
• Regional air quality considerations are good for making broad
estimates of the relative air quality impact of alternative
plans but, are totally insufficient for the level of detail
required to form the basis for evaluating subarea planning
alternatives.
• Regional scale air pollution considerations are not applicable
to the explanation or solution of microscale problems (i.e.,
CO over short time periods and small distances is more likely
to be determined by localized influence or short-term extremes
in meteorological conditions).
0 The regional scale air pollution considerations are appropriate
within the planning process to improve regionwide air quality
and reduce exposure to the general population and high risk
groups within the general population to high concentrations.
0 If total concentrations do not exceed AAQS and if the variation
in total regional impact among plan alternatives is less than
15 percent, the planner can be neutral in the choice of a plan
with regard to regional air quality considerations.
0 If background air quality concentrations exceed 60-70 percent
of total regional concentration, land use planning is not an
effective abatement strategy for regional problems.
B-4
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0 Plan design factors having a primary influence on regional air
quality concentrations and spatial pattern are:
Percent mix of land use (manufacturing and transportation
dominate)
Location of land use
Intensity of land use (clustering)
0 Local topographic and meteorological conditions have a major
influence on air quality patterns.
The following recommendations for further study were made by ERT
based on the results of the study:
0 Refine emissions data, especially activity indices and pro-
jection indices.
0 Develop further default parameters.
0 Further calibrate the air quality model (MARTIK). Meteorological
effects studies are needed for model validation.
0 Develop a software interface between AQUIP and the comput-
erized data base of air pollution agencies.
0 Refine "rapid estimation techniques" for evaluation and
ranking of plans.
0 Extend AQUIP to the microscale.
0 Perform sensitivity analysis and development guidelines for
impact.
0 Examine air quality in relation to other environmental and
planning issues, (i.e., water quality, solid waste, cost/
benefit, etc.).
E. Data Requirements
To complete the entire AQUIP sequence, detailed land use intensity
or activity, emission factors, meteorological and topographic, ambient
air quality, and conversion of default parameters are needed. Accuracy
is greatly reduced if any of these data are missing.
B-5
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The initial idea was to develop guidelines for preparing air pollution
elements in local general plans. However, this idea was dismissed
because of the regional nature of the air pollution problem resulting in
several technical and administrative problems. Instead, a combination
regional/subarea approach to integrating air quality goals into the
planning processes was suggested as a solution.
The process consists of six steps: (1) compiling detailed inven-
tories of air polluting emissions in subareas of air basins, (2) designating
maximum emissions allowable in each subarea, (3) projecting subarea
emissions likely to be generated by sources indicated in land use and
transportation plans for future years, e.g., 1985 and 1995, (4) evaluating
and revising the plans so that the maximum emission limits are not
exceeded, (5) adopting and implementing the plans, and (6) monitoring
public and private development through a refined environmental impact
assessment process. The key to the process is the concept of allocating
allowable emissions to subareas within air basins. The premise is that
the emission limits will be set up so that air quality standards will be
met if plans and projects conform to the limits. An appeal process is
suggested to allow deviations in those cases where technical information
is available to ensure that air quality standards will not be violated.
B. Analytic Techniques
The study recommends the application of several analytic techniques
as follows:
1. Land Use Model
This requires at least three sectors of land use—manufacturing,
residential, and commercial with land use inventories and projections
developed by subarea.
B-6
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F. Model Calibration
Existing ambient air quality and meteorological data were used to
develop simple ratios of existing to projected data to calibrate the
model. Where meteorological or topographic conditions vary signifi-
cantly from the Meadow!ands conditions, the model would require exten-
sive recallbration.
G. Model or Study Status
AQUIP is operational for the Hackensack planning region only and is
currently operational on the ERT computer only.
H. Applicability to Other Areas
Based on the characteristics of the Hackensack land use plans, the
following can be said: (1) some new routines would be required to
reflect the appropriate planning assumptions of new planning develop-
ment. However, the overall AQUIP procedures and subroutines are suffi-
ciently general to be applied wherever cientata are sufficient to operate
them, (2) the explicit quantitative results are less generally appli-
cable as they are representative of the meteorology and topography of
the Meadowlands. Any variation from these conditions must be considered;
and (3) AQUIP can be used as a projection tool as well as a diagnostic
tool, (i.e., it can be used to evaluate strategies).
A REPORT ON GUIDELINES FOR RELATING AIR POLLUTION CONTROL TO LAND USE
AND TRANSPORTATION PLANNING IN THE STATE OF CALIFORNIA
A. Study Purpose and Scope
The study purpose was to prepare guidelines for integrating the
goal of achieving and maintaining air quality with the land use and
transportation planning processes in California metropolitan regions.
B-7
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2. Data Allocation or Disaggregatlon Technique
This provides for disaggregation of land use data to subarea level
for analysis.
3. Previous Emissions Inventories
Existing inventories for counties and air basins are too general
for detailed air quality planning; thus, it is suggested that Basin
Coordinating Councils compile planning subarea emissions inventories.
4. Emissions Inventory Development
The study suggests that total emissions inventory be composed of
three separate inventories: (1) point sources, (2) stationary source
area sources, and (3) mobile source area sources.
5. Emissions Model
The emissions model consists of the methodology used in developing
the inventory. Future emissions are projected for 1985 and 1995 based
on current or modified emission or emission density factors and projections
from land use and transportation plans of: (1) either point source emis-
sions or source parameter data, (2) area source acreage by land use
category, (3) vehicle-miles traveled.
6. Air Quality Model
No sophisticated validated air quality model is presently available
to predict values in California air basins. It is recommended that the
initial program use the proportional model or roll-back technique with
provisions for deviation from the model where technical information is
available to ensure that ambient air quality standards not be exceeded
by the proposed deviation.
B-8
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C. Application
The application is intended for the air basins of the State of
California.
D. Study Recommendations/Conclusions
The study recommends a regional/subarea approach to integrating air
quality goals into land use and transportation plans, rather than the
development of separate air pollution elements to local general plans
and regional transportation plans.
The study also recommends emissions allocation as a control method,
with provisions for allowing deviations from emissions limits where an
adequate case can be made for the deviation not interfering with attain-
ment or maintenance of air quality standards.
It is recommended that stationary sources be separated into high emit-
ters and low emitters, treating the former as point sources, using point
source emission factors, and the latter as area sources, using emission
density factors. Mobile sources are treated as area sources, but emissions
are based on vehicle miles of travel.
More refined models are recommended for predicting air quality as they
are calibrated and validated for California. Periodic updating of emis-
sion and emission density factors is also recommended.
E. Data Requirements
Land use parameters include acreage, residential density, nature of
uses, production level, fuel consumption, location with respect to transport
facilities, and other physical and socioeconomic variables. Transporta-
tion factors include vehicle miles of travel and speed. Emission require-
ments include point source emission factors based on process weight,
energy consumption, etc. Emission density factors for low emitter
stationary sources are also required.
F. Validation or Calibration
The proportional model has so far proven to be as reliable as would
be derived from a more complicated method. However, more refined models
B-9
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calibrated or validated for individual air basins in California would
be desirable. Currently, research is underway to develop such models in
the San Francisco Bay Area, in the South Coast Air Basin, and in San
Diego.
G. Model or Study Status
The study presents a set of recommended guidelines, application
results have not been published.
H. Applicability to Other Areas
The guidelines recommended are generally applicable to any area.
B-10
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III. THE TRANSPORTATION AND AIR SHED SIMULATION MODEL (TASSIM)
REPORTS, DOT-OS-30099-3 AND DOT-OS-30099-4, MARCH 1974
A. Study Purpose and Scope
The purpose of this study was to develop a model that
integrates existing urban transportation models, vehicle emission
factors, and a simple air diffusion model to analyze the air
quality effects of various transportation policies. The model
was calibrated and applied for the Boston area, disaggregated
into 122 sub-areas to simulate the air quality effects of various
transportation controls, land use controls, and stationary
source policies. The model structure and several model applications
are described.
B. Analytic Technique
The TASSIM computer technique is composed of three separate
programs, each of which has two or more sub-programs.
1. TASAQD Program -- The TASAQD program is a simplified version
of the Air Quality Display Model (AQDM) which models air pollutant
concentrations in each sub-area resulting from individual large
point sources. The basic simplification is the substitution of
a single typical stability class.
2. TASSIM Program -- The TASSIM program contains the following
seven sub-programs.
t TRGEN - Total person trips are projected to and from each
sub-zone. This sub-model uses the trip generation
equations and zonal land activity data typical to most
urban transportation studies.
• TRIPAL - Zonal productions and attractions developed
by TRGEN are used; trip distribution, mode split and
network assignment to a composite highway and transit
district or "spider" network are performed.
B-ll
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• EMIT - Auto emissions are calculated based on the
network assignments and speeds and combined with non-
mobile area emissions to produce air quality surfaces
for the region. The frequency with which the Federal
standards are exceeded in each of the sub-areas is
determined. The diffusion model used for mobile and
area sources in this sub-program is a Gaussian vertical
distribution (Hanna-Grifford model).
• MODSPT - Adopts the mode split models developed in the
urban transportation study to the district level
composite highway and transit network to produce
estimates of transit person and auto trips for various
pricing, level of service, and control policies.
• TRPDST - The gravity model is used for person trip
zonal distribution to the district level network.
• SKIMT and JAY - Interdistrict impedance is calculated using
a modificaton of the "Moore" minimum path model.
Highway only and combined highway-transit network
inter-district impedances are calculated and used as
input to the mode split model.
• DIAL and DIALT - Transit trips are assigned to the
transit subnet. A version of the parallel probabilistic
assignment algorithm to assign auto person trips to
the composite auto-transit network is used.
3. TASMAP Program — The TASMAP program generates maps portraying
the geographical concentrations or concentration changes using
the data developed by the diffusion models.
C. Application
The models described above were calibrated for the Boston
regional area and applied to test the effect on air quality by
(1) reducing vehicular emissions, (2) applying various prohibition
and licensing schemes to auto trips, (3) increasing auto occupancy,
(4) reducing transit fares, (5) improving performance of high-
way and/or transit systems, (6) controlling urban development patterns,
and (7) reducing stationary source emissions.
B-12
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The regional and sub-area air quality for 122 sub-regions
were evaluated for the total pollutants, TSP, S02, CO, HC, and
NO , and the change in these pollutants with the various policies
and system changes listed above.
D. Study Recommendations and Conclusions
The application for the Boston area permitted an analysis
of a wide variety of factors that would affect the air quality.
The TASSIM model contains sub-models for trip generation, trip
distribution mode split, assignment, composite highway and
transit network representation, point source emissions, area
source emissions and mobile source emissions, as well as a
diffusion model. It also provides for analysis at the sub-area
level as well as the regional level. Because the model chain
contains all sub-models which are executed very economically in
sequence, the effect of policy decisions on the entire model
chain can be analyzed for a large number of policy considerations
at the sub-region as well as the regional level.
Some general conclusions resulting from the analysis are:
0 It is important to consider the total effect of localized
air quality control policies since an improvement of
air quality may occur in one sub-area but may be
reduced in other sub-areas.
• Reducing vehicle emissions to the level set forth in
the 1970 Clean Air Act is an effective technique for
improving air quality in the metropolitan area.
• The spatial distributions of emissions, and not just
the metropolitan-wide aggregate of emissions, must be
considered in order to effectively evaluate the effects
of individual policies or combinations of various
policies.
B-13
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• It is difficult to generalize about the effectiveness
of point source controls because the relationship
between point source and concentrations vary widely
due to the local meteorology, topography, and the
location of large point sources.
• An evaluation of the cost and effectiveness of various
policies indicate some of the control strategies
analyzed produced small improvements in air quality at
relatively large cost.
E. Data Requirements
To apply the TASSIM model requires (1) subarea, interarea
travel times and trip interchange; (2) inventories of stationary
emissions; (3) meteorological parameters; (4) vehicle emission
rates; (5) social-economic characteristics of the population for the
calibration and application of the trip generation and mode split
equations; (6) person trip generation equations (usually developed
as part of the transportation planning process); (7) "Gravity Model"
trip distribution procedure ("F" and "K" factors developed as part of
many of the transportation plans); and (8) "Model Split
Model" to be applied to person trips distributed by the gravity
model.
F. Calibration
The models for trip generation, trip distribution, and mode
split developed as part of the transportation planning process,
were used with 1970 census land activity data and employment
data, and the forecasted air quality compared favorably to the
monitoring data collected in the area. If the trip generation,
trip distribution, mode split models, interarea travel times
trip interchange, and inventory of stationary sources are available,
the model could be calibrated for other metropolitan areas.
B-14
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G. Model or Study Status^
The TASSIM model is operational, and FORTRAN decks of the
programs have been executed on an IBM 370/145 and 370/165.
H. Applicability to Other Areas
The TASSIM model is designed to use data and models developed
by many of the urban transportation studies. If person-trip
generation equations, gravity type distribution models, and
post-distribution mode split models are available, the TASSIM
model could be calibrated and applied. In some cases substantial
modification would be required to the TASSIM model to accommodate
the models generated by the transportation study. The model
would be applied at a 100 to 200 sub-region area level. These
sub-regions would probably be combinations of the 600 to 1000
transportation planning zones to facilitate the model calibration
data developed in the transportation study at the zone level.
The model uses a district level spider network in which all
highway and transit facilities are represented by direct connection
between district centroids. These "links" are encoded with
average characteristics of all the transportation facilities
they represent. For the mobile source emissions, the number of
vehicles assigned to the link and the adjusted speed assigned to
the link are used to calculate the emissions of all facilities
represented by this link. They are prorated to the two sub-
areas connected by the link based on the square root of the area
of the sub-regions. With this technique it is difficult to
identify the unique characteristics of specific facilities and
the effect traffic volume would have on the operating speeds of
individual routes.
B-15
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IV. AIR POLLUTION/LAND USE PLANNING PROJECT, PHASE II, FINAL
REPORT, VOLUME II, ARGONNE NATIONAL LABORATORY, CENTER FOR
ENVIRONMENTAL STUDIES, MAY 1973.
A. Study Purpose and Scope
The general purpose of the project was to examine relation-
ships between air quality and land use guidance and control
practices. The specific objective of the work was to investigate
the utility of various land use parameters in describing the air
quality impacts of land use plans. The Chicago metropolitan
region was used as the test region.
B. Analytic Techniques
The methodology envisioned predicting the air quality
impacts of land use plans from various land use parameters, a
part of which involved the following:
(1) A land use model was used to forecast growth or change
in land use based on rates of change in land use,
employment, and productivity for the different kinds
of manufacturing land uses, changes in housing stock
and population for residential land use, and changes
in square footage of floor space for commercial land
use.
(2) An emissions model was based on either emission density
factors (emissions per acre) or other emission factors
to relate emissions to land uses.
(3) An air quality model was used to determine air quality
levels in the region, assuming knowledge of quantity
of emissions. The air quality model used was the Air
Quality Display Model.
The work described examined the feasibility of developing
useful emission factors for an emissions model. Only one pollutant
particulates, was examined as a test case.
Separate analyses were conducted for manufacturing land use
and for residential/commercial land use.
B-16
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For manufacturing land use, two methods of developing emission
factors were tried. The first method was to develop emission density
factors. Four sets of emission density factors, based on mean,
median, and "best fit" representations of source inventory data
were tried. The usefulness of each set of emission density
factors was determined by seeing how well the air quality representation
obtained using the factors compared to the air quality representation
obtained using the point source emissions data.
The second method was to test the feasibility of using some
combination of the following parameters—number of employees,
process weight, fuel consumption as well as acres of land-to
forecast emissions of manufacturing activities. Linear regression
was used as a method of analysis. Statistical tests such as
correlation coefficients were used to judge usefulness of parameters
for prediction.
For residential/commerical land use, the observation was
made that for particulates, emissions were a direct function of
fuel consumption and therefore, it was sufficient for predicting
fuel consumption. The land use parameter used for predicting
residential fuel consumption was mean energy use per dwelling
unit, by dwelling unit category. Commercial fuel consumption was
predicted by considering mean energy use per thousand square
feet, by commercial size category. Analysis of variance was
used to determine the breakdowns of dwelling unit categories and
of significant commercial size categories.
C. Application
The test analyses were performed on data from the Chicago
Metropolitan Air Quality Control Region. The primary data
sources used were emission inventories collected by the City of
Chicago and the State of Illinois Environmental Protection
B-17
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Agency and land use data on a square-mile basis collected by the
Northeastern Illinois Planning Commission.
D. Conclusions
(1) None of the four sets of emission density factors
tested predicted air quality deterioration from manufacturing
land use sufficiently well. Thus, the emission density-
concept was rejected.
(2) One of the linear regression models tried to predict
manufacturing emissions on the basis of number of
employees and acres of land. As these two parameters
are easier to predict or more likely to be predicted
in most land use planning than the other two parameters
being examined, the model was an effort to determine
if they were sufficient to predict manufacturing
emissions. They were not. The linear regression
model based on all four parameters, however, was
sufficient. An attempt was also made to see if number
of employees and acres of land could be used to determine
the other two parameters, process weight and fuel
consumption. If the latter two could be determined
from the former two, input would then be available for
prediction of emissions from the four parameter model.
However, the results were inconclusive.
(3) For prediction of residential emissions, the breakdown
of dwelling unit categories that was determined signifi-
cant was between light residential (less than or equal
to twenty dwelling units per building) and heavy
residential (more than twenty dwelling units per
building). For prediction of commercial emissions,
the breakdown of commercial size categories that was
determined significant was between light commercial
(less than or equal to 20,000 square feet per building)
and heavy commercial (more than 20,000 square feet per
building). Mean energy use per dwelling unit or per
thousand square feet were determined for each category
and were found useful predictors of emissions.
E.F.G. Data Requirements. Model Calibration, Model or Study Status
The Argonne project terminated before a methodology or
model for predicting air quality impacts of land use plans from
land use parameters was developed.
B-18
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H. Applicability to Other Areas
The approach taken by the project is applicable to other
areas. However, the specific research results for the emission
model cannot be assumed applicable to other areas, as they
reflect data specific to the Chicago region.
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V. BALTIMORE REGIONAL ENVIRONMENTAL IMPACT STUDY (BREIS) — ALAN M.
VOORHEES AND ASSOCIATES, INC., MARCH 1974.
A. Study Purpose and Scope
The purpose of BREIS was to evaluate the regional environmental
impacts of alternative land use and transportation policies in the
Baltimore region. Several environmental analyses—air, noise, water,
solid waste, socioeconomic, and traffic—were performed for a 1970
base year plus three 1980 alternatives and four 1995 alternatives for
the highway system.
B. Analytic Techniques
The Urban Systems (USM) land use model was first used to determine
regional development data for each of the alternatives. Next, a series
of transportation models was used to determine trip generation, modal
split, and traffic assignments for each alternative.
An emissions model was developed to calculate motor vehicle emis-
sions by link and by trip ends (for cold start and hot soak emissions)
from the output of the transportation models. Emissions of CO, HC, and
NO were summed to the regional planning district level and further
A
summarized by county and for the entire study area. Comparison of
emissions from different alternatives indicated the effect of the highway
system on automotive emissions and the trend in emissions over time
(1970, 1980, and 1995).
Emission data for stationary sources and non-automotive mobile sources
were obtained from available inventories. These were projected by a two-
step procedure. First, controls that would be applied to individual
point sources in the future and to area source categories were esti-
mated. Then, the controlled emissions were increased by use of appro-
priate growth factors from the Urban Systems Model data or U.S. Depart-
ment of Commerce projections to account for growth. The two partial
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inventories were combined to show the differences in total emissions by
alternative and the contribution of motor vehicle emissions in each case.
C. Model Application
For pollutants other than CO, maximum projected concentrations were
simply estimated by proportional reduction with the emissions data. For
carbon monoxide, the APRAC-1A urban diffusion model was used to determine
maximum CO concentrations for each alternative. Areas of high suspected
concentrations were found by using the grid-point version of that model.
Then, receptor points were specified in the areas indicated by the grid-
point version to have high background levels, and the synoptic version
with the street-canyon subroutine was used to estimate maximum 1-hour and
8-hour concentrations alongside the major streets in those areas.
D. Conclusions and Recommendations
The results of this study have been used by Federal agencies to
assess the regional impact of alternative land use and transportation
policies. Because the traffic data was prepared at link level it has
been possible to perform micro level CO analysis as well for assessment
of highways at the project level. Further applications will be completed
for the efforts of transportation control strategies and energy consump-
tion. The local decisionmakers are utilizing the results to further
evaluate alternative policies.
E. Data Requirements
The procedure applied in Baltimore served to update the 3-C trans-
portation plan as well as to provide a regional environmental assessment.
Thus, the activity allocation model and the travel simulation models
required input data at the zonal level (approximately equal to two to five
square miles) as part of the overall process. The air quality and other
environmental assessments were conducted at a more aggregate level.
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F. Model Calibration
The land use and transportation models were calibrated according to
standard practice. The CO model was calibrated on limited receptor
sites.
G. Model or Study Status
The BREIS study is essentially complete; however, ongoing analysis
will further refine the data and the procedures.
H. Applicability to Other Areas
The approach is readily applicable to those areas that have a
quantified land use model and/or a comprehensive update of the trans-
portation modeling process. It can be used to evaluate alternative plans
as well as incremental plan changes.
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APPENDIX C
ANNOTATED BIBLIOGRAPHY OF ACTIVITY
ALLOCATION PROCEDURES
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ANNOTATED BIBLIOGRAPHY OF ACTIVITY ALLOCATION PROCEDURES
This technical appendix is intended to inform the reader of some of
the activity allocation procedures which have been developed and applied
in the United States and elsewhere. The probabalistic models described
are the outgrowth of the studies of Ira S. Lowry in Pittsburgh and of
A. G. Wilson in England (see Figure of page C-6). Other models, such
as EMPIRIC, are econometric-type models.
Batty, Michael. Recent Developments in Land Use Modeling: A Review of
British Research. Urban Studies. June 1972.
This paper is primarily a discussion of the development and appli-
cation of Lowry-type models in England. These models have dominated
British research and have been strongly influenced by A.G. Wilson's
entropy-maximizing framework. Wilson's framework, which explicitly
identifies spatial interaction in terms of stocks and flows of activities,
provides a strong theoretical basis for refinements of the original
Lowry model. Building on Wilson's work, British researchers have devised
several constraint procedures that are consistent with Garin's matrix
solution of the Lowry model.
Several Wilson-Garin-Lowry models with constraints have been tested
at the subregional and town levels in Britain.
Batty reviews the current research undertaken in England to address
the following problems:
• The static equilibrium nature of model projections
• The lack of feedback between the population and service
sectors and the basic sector
• The slow convergence of the constraints procedure under model
Modification I
• The basic-service definitional problems
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• Improved parameter estimation techniques
• The optimum level of aggregation for the model (both in terms
of level of analysis and level of data)
Batty concludes that the Wilson-Garin-Lowry formulation is flexible
enough to allow for the solution of the above problems and the incorporation
of other model refinements as current research introduces them.
Berry, Brian J. L. The Retail Component of the Urban Model. Journal of
the American Institute of Planners. May 1965.
The author analyzes work done in Chicago to identify the structure
of retail markets in an urban area. He concludes that the correct
ecological units for measurement of retail market areas are not transpor-
tation zones or census tracts, because they cut across market bouridries.
Larger analysis units, however, are more likely to capture the effects
of the retail business center on its market area. The most useful
definition of market area is seen to be the area in which a constant
rate of accumulation of trips with distance holds.
The author employs factor analysis to determine the nature of the
interdependences among variables indicative of the size and complexity
of the retail centers. Variables tested include functions, establish-
ments, total center area, shopping center area, ground floor area, area
of trade area, median income, social class, family class, total compe-
tition, planned competition, unplanned competition, ribbon competition,
discount competition, and population density.
The results of the factor analysis suggest that the number of
functions and their size are highly related to the population of the
market area area and the position of the retail centers in a hierarchy.
Other independent factors, which are identified by factor analysis, are
population of the trade area and the independent variables above are
regressed by Berry to produce estimates of retail market area size for
planned and unplanned centers.
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Chapin, Stuart F., Jr., and Shirley F. Weiss. A Probabilistic Model for
Residential Growth. Transportation Research. December 1968.
Chapin and Weiss view urban land development as a dynamic process
involving priming actions such as the building of expressways and major
industrial parks which promote secondary actions such as the opening of
shops or the choice of residential locations. The authors have focused
their efforts on the study of residential land use conversion and have
determined that the most influential factors in this process are margi-
nal land not in use, accessibility to work, and assessed value.
A Monte Carlo simulation technique (linear form without replace-
ment) is adopted by the authors to distribute the expected level of new
housing units to grid cells on the basis of attraction probabilities.
Assessed values are used in computing the initial attraction probabi-
lities, while density and housing value constraints are imposed to
modify these initial probabilities. Ten density-value classes for
subdivided and raw land are considered by the model.
After each simulation period, the attraction probabilities for each
grid cell are modified according to anticipated new priming actions and
the effects of the land market in the previous development period. The
model developed by Chapin and Weiss allocates discrete household units,
and the number of these units to be allocated in each simulation period
is exogenously specified.
The model is applied to Greensboro, North Carolina, for the years
1948-1960 with three-year simulation periods. The results indicate that
the model may be used as a tool for investigating the effect of different
land use development policies on residential location patterns. In the
future, the authors are hoping to develop submodels which simulate human
values ana oehavior patterns in order to better understand the primary
influences on location decisions.
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Cripps, E. L. and D. H. S. Foot. A Land Use Model for Subregional
Planning. Regional Studies. December 1969.
Wilson's entropy-maximizing approach has been applied in a Lowry-
type model to several regions and towns in England. This paper is a
full description of the application of such a model to the Bedforshire
multimodal subregion.
The model, which strongly resembles the Urban Systems Model, is
calibrated and applied in order to allocate population and service
employment to 130 zones. Plots of actual and estimated activity are
included in the paper as well as statistical indicators of the fit.
From the trip tables produced by the model, desire lines of spatial
interaction are examined to ensure that trips between selected towns are
adequately simulated.
In general, the authors find that the model is able to produce the
existing activity structure of the subregion within a reasonable margin
of accuracy and that the small-area projections made by the model are
sensible. However, the authors note the limitations of the static
equilibrium form of the model in describing the process of urban growth
and development.
The activity allocation model applied in Bedfordshire has a second
shortcoming cited by the authors. The model treats locational factors
after the decision to move has been made. The authors contend that
there is a need for behavioral submodels which simulate the motivation
to move itself. They reveal that such work is already done by A.G.
Wilson using the same framework as the Bedfordshire model, and they
conclude that such research represents the proper focus for future
modeling of locational decisions.
Evaluation of Regional Economic Effects of Alternative Highway Systems.
Curtis C. Harris Associates, Inc. FHWA Report, January 1973.
This report summarizes the development and application of a national
econometric model which projects population, employment, income,
C-4
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investments, consumption, and government expenditures by 1973 QBE regions,
The model contains system sensitive components which may be used to
evaluate the effects of alternative transportation systems on regional
activity levels. These components are embodied in the transport shadow
prices which are derived by solving a linear programming algorithm for
each industry.
The transport shipping costs developed by Harris include truck and
rail operating costs. The treatment of these costs is of particular
interest because the future location of basic employment may be influ-
enced by the level of truck and rail service.
The calculation of rail rates is based on the mark-up of out-of-
pocket costs incurred by the carrier. Out-of-pocket costs include
terminal and line haul expenses averaged over an extended time period.
These costs do not include equipment depreciation rates and overhead
expenses. The mark-up factors which reflect revenue to out-of-pocket
ratios for each region, are derived from the Annual ICC publication,
Procedures for Developing Rail Revenue Contribution by_ Commodity and
Territory.
The methodology for developing truck operation costs which are
sensitive to highway system changes relates ICC average operating costs
per mile at specific speeds to the TRANSNET network. The ICC operating
costs are adjusted to reflect the type of road and terrain and penalties
for driving through or around major urban areas. Five highway types are
considereu.
(1) limited access, divided toll;
(2) limited access, divided free;
(3) other divided;
(4) principal through highways; and
(5) local connectors.
These types are further divided into four speed categories depending
upon the terrain.
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The speeds associated with the TRANSNET network reflect composite
automobile-truck speeds. Therefore, TRANSNET speeds are adjusted to
reflect average truck speeds by the following formula:
TS = .7715
where:
TS = Average truck speed, including stops
S = TRANSNET composite speed
The truck operating cost per vehicle mile is calculated for each
state on the basis of the ICC cost-speed data and the TRANSNET link
truck speeds. The cost per vehicle-mile is then used in TRANSNET to
compute the minimum truck cost path between QBE regions.
In order to account for the friction of traveling through or around
urban areas, TRANSNET imposes time penalties, depending on the size of
the city. In the Harris study, these penalties are increased by two
minutes for truck travel and are converted to costs using the ICC median
hourly truck operating costs.
By substituting truck costs for speed and time data in TRANSNET,
the Harris study has developed a methodology which is sensitive to the
changes in the highway system. For example, truck operating costs may
be decreased by the upgrading of a highway or the building of a bypass
around an urban area. The major assumption that is made in developing
the truck cost methodology is that motor carrier rates will actually
adjust to reflect such improvements in the highway system.
Goldner, William. The Lowry Model Heritage. Journal of the American
Institute of Planners, March 1971.
This article is a review of the basic Lowry model and its descen-
dants. The structure of Lowry's original model is discussed, and tables
of the Pittsburgh calibration parameters, allocation weights, and minimum
C-6
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service employment thresholds are presented. The subsequent theoretical
and operational revisions of the Lowry model discussed by Goldner are
summarized in the following tree:
Lowry Model (1962)
w/Rand for Pittsburgh
J
TOMM (
Crecin
Pittsb
1
TOMM I
I
1964) BASS I
e for Goldner &
urgh at Ber
i
Gar in
Contribut
r
I (1968) i
1
(1965) CLUG (1966)
Graybeal Feldt
keley Cornell
r
-Rogers
ions (1966)
t
Crecine for
Metro Project
Univ. of Mich.
PLUM (1968)
Goldner for
San Francisco
A.G. Wilson
Contributions (1968)
at Center for Environmental
Studies, London
1
Urban Systems Model
Christopher Turner
at
Alan M. Voorhees & Associates
Under the aegis of A. G. Wilson, the Lowry model has been applied
at the subregional and town scale throughout England. Empirical work
C-7
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with the model in England has contributed meaningful improvements to the
original form.
Goldner maintains that the differences among Lowry-type models are
reflected in the following considerations: (1) treatment of the time
dimension, (2) degree of disaggregation, (3) handling of development con-
straints, (4) definition of the areal units, (5) number of variables
considered, and (6) calibration and evaluation techniques. Each of the
Lowry model descendants are examined with respect to these model
considerations.
Goldner concludes that the "promise of meaningful operationality"
which characterizes the original Lowry model has inspired a host of
variants developed for various planning applications. Although many
Lowry descendants in America have failed to reach operationality, British
modelers have applied the model at "conceptual, experimental, and
operational levels."
Illinois River Basin Pilot Project. Argonne National Laboratory.
January 1973.
The socioeconomic/land use mathematical model (SELUM), which was
developed in conjunction with the Illinois River Basin project, is
similar to the trend analysis technique used in Missouri. The methodo-
logy suggested for projection and allocation of state activity levels
involves the identification of subregions in the state. These subregions
are defined on the basis of activity growth patterns over time, i.e.,
fast, stagnant, and independent. Trend projections of activity are then
made by subregions, counties, and municipalities.
The Illinois activity allocation methodology assumes that the more
aggregate projections are most accurate. Therefore, county trend projec-
tions are normalized to the appropriate subregional projection, and
municipality totals are normalized to the adjusted county projections.
r Q
L-o
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The most attractive feature of this simple state projection and
allocation methodology is its flexibility and ease of utility. Data
requirements are small. Data for several points in time are the only
requirement for the projection of any activity. In addition, the
processing of data is greatly facilitated by the package of manipulation
and analysis programs developed for the Illinois project.
Kilbridge, M. D., Robert P. O'Block, and Paul V. Teplitz. A Conceptual
Framework for Urban Planning Models. Management Science. February 1969.
The authors present a framework for classification of urban plan-
ning models which emphasizes the basic characteristics of the model
rather than the application. The basic elements which are evaluated for
twenty major models are: subject land use, transportation, population,
and/or economic activity; function (projection allocation and/or derivation);
theory (such as market theory, location theory, and gravity theory); and
method (econometric, stochastic, mathematical programming, or simulation.
The authors also address the problems inherent in model building
efforts including the lack of adequate data and urban theory to support
the construction of models which accurately reflect urban phenomena.
King, Leslie J. Models of Urban Land Use Development. Models of Urban
Structure. Lexington, Massachusetts, Lexington Books, 1969.
This paper is a summary of methods for classifying urban develop-
ment models, as well as an evaluation of the most influential models
which have been constructed. The author reviews the model classifica-
tion schemes suggested by Harris, Kilbridge, et. al, Wilson, and Lowry,
and then introduces his own systems analysis framework. This framework
involves a ranking of models based on the level of abstraction which
characterizes the model. The ranking continuum ranges from empirical
observations to simulation techniques to mathematical analyses.
C-9
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Empirical observations include such "models" as Burgess1 concentric
zone theory and Hoyt's sector hypothesis. Simulation techniques include
both gaming models and Monte Carlo simulations. King describes the most
famous urban gaming models, such as CLUG, METRO, and CITY, and summarizes
the uses of Monte Carlo techniques in model building. The most abstract
technique, that of mathematical analysis, is used in many urban devel-
opment models, and the author describes the general algorithms of
POLIMETRIC, EMPIRIC, and Lowry-type models. Several normative models
are discussed, including the Herbert-Stevens linear programming formu-
lation, and significant stochastic approaches are reviewed briefly. The
final recommendations of the author are addressed to agencies of small
metropolitan areas and these include:
• Delineate specific goals with respect to land use development
t Implement (even a simple linear regression) forecasting model
• Consider participation in an urban simulation game
Model for Allocating Economic Activities into Subareas in a State. Alan
M. Voorhees and Associates, Inc. McLean, Virginia. Report for the
Connecticut Interregional Planning Program. May 1966.
A differential shift model is developed to allocate manufacturing
employment, population, and service employment by type to small areas.
The model is a set of simultaneous equations with independent variables
which include lagged dependent variables, holding capacities, and
accessibilities. The differential shift, which is the dependent variable
for each activity type, is added to the proportional share of state
growth to determine the net change in small area activity over the
forecast interval. The model is applied in distributing activity to 169
Connecticut towns, while a second set of similar models is applied to
distribute activity from towns to 804 traffic zones.
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Readings in Economic Geography. Smith, Robert H. T., Edward J. Taaffe,
and Leslie J. King (eds.). Chicago, Rand-McNally and Company, 1968.
This book is a collection of classical and modern readings in
location theory. The sections of most interest with respect to the
development of a state activity allocation model involve discussions of
central place theory.
In an early section, Brian J. L. Berry and Allan Pred discuss W.
Christaller's classical formulation of central place theory. Christaller
maintains that regions are characterized by a system of central places
whose arrangement is ordered on the basis of three competing principles;
namely, marketing, administration, and transportation. Christaller also
hypothesizes that the range of a good is determined by the size of the
center, the income of the consumer, subjective economic distance and the
quantity and price of the good.
John E. Brush presents results of an empirical study of Southwestern
Wisconsin which support many tenets of classical central place theory.
The settlements or trade centers in the study area are ranked as hamlets,
villages, or towns, according to the number of trade functions which
they perform and their spatial location. Brush concludes that trade
centers in Southwestern Wisconsin are distributed in a radial-circular
fashion, supporting the central place hypotheses of Kolb rather than
those of Christaller. Brush maintains that trade center hierarchies in
America differ from those in Europe and Africa. However, he concludes
that it may be possible to formulate hierarchy guidelines which are
applicable to similar regions in America.
Two other articles dealing with applications of central place
theory are of special interest. A set of general equations is presented
by Berry and Barnum to summarize the fundamental characteristics of
central places. Specifically, the relationships between the trade area,
the population served, and population densities are plotted for four
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regions. In a second article, Barry, Barnum, and Tennant's application
of central place theory to Southwest Iowa suggests that factor analysis
is a useful tool for determining the hierarchy of central places.
A Review of Operational Urban Transportation Models. Peat, Marwick,
Mitchell, and Company. Final report submitted to FHWA, April 1973.
This document is a summary of operational urban transportation
procedures including five major activity allocation models: PLUM, USM,
EMPIRIC, Accessibility-Opportunity, and UPM. The comparison of activity
allocation models is preceded by a discussion of the appropriate evalua-
tion criteria and these are considered to be: conceptual structure,
solution method, policy sensitivity, level of detail, transferability, and
man-machine interface. Each of the five models is evaluated with respect
to these criteria. The major advantages and disadvantages of each model,
as cited in the report, are summarized below.
PLUM or the Projective Land Use Model is a static equilibrium Lowry-
type model with a deductive theoretical base. PLUM provides an option
for highly disaggregate output (if stratified input data is available)
and a land use accounting system is integrated into the structure of the
main model. Submodels are also available in the PLUM package for the
projection of socioeconomic data. PLUM suffers from the same disadvantages
as other Lowry models in that the basic-service employment split is diffi-
cult to determine and the model requires exogenous allocation of forecast
year basic employment by small areas.
In many respects, the USM or Urban Systems Model is similar to PLUM.
It also is a Lowry-type, static equilibrium model, and therefore has a
tight, theoretical structure. However, the USM has a simple and more
clearly defined calibration process than PLUM due to its repeated appli-
cation and modification in Britain. The USM does not contain an explicit
land use accounting procedure, nor is the current form of the model able to
C-12
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produce disaggregate activity types. The general limitations of
Lowry-type models are discussed above. These drawbacks are also appli-
cable to the USM.
EMPIRIC is a completely different type of model from the preceding
two. The basic structure of the model is a set of three to 15 simultaneous
equations, depending on data availability and desired disaggregation of
the output. The dependent variables in these equations represent
changes in shares of activities over the forecast interval. The esti-
mation of coefficients for the model variables is a complex procedure
which requires a highly trained analyst. However, the package of data
manipulation programs which accompanies the basic model facilitates the
calibration process. EMPIRIC activity output is generally disaggre-
gated, i.e., population by income group and employment by SIC group, and
subordinate models are available for projecting land consumption and
socioeconomic variables.
The Opportunity-Accessibility Model has a similar structure to that
of the basic modules of PLUM and the USM. The model has been used
primarily in allocating trip ends for transportation studies in urban
areas. Because of its principal use as an impact analysis tool, its
input data requirements are relatively small, and its output is of an
aggregated form. Its simplified structure precludes the testing of non-
transportation policies, an option which is available within the other
four models. Transferability of the model is limited, since it is not
actively supported by a staff effort.
The UPM or Urban Performance Model is a time-dependent model with
an attractive conceptual structure based on utility theory. The model
is principally noted for its use of "opportunity" and "quality" measures
which provide a simple and effective framework for the evaluation of
urban area projections. Some UPM forecasting options have not been
fully tested, however, and the calibration process is not well defined.
Therefore, the utility of the UPM in terms of producing urban area
projections is as yet unknown.
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STAM Socioeconomic and Land Use Data File. West Virginia Department of
Highways. March 1972.
West Virginia is developing a comprehensive 1970 socioeconomic and
land use data base as part of a Statewide Traffic Assignment Model
Study. The socioeconomic variables which are being collected at the 778
zone level can be allocated to the following seven categories: population,
auto registration, employment, indices of productivity, education,
indices of community structure and accessibility, and recreation of index.
Work sheets and detailed instructions for implementing the data
collection process are provided in the West Virginia Manual.
A Summary of the Urban Systems Model. Alan M. Voorhees and Associates,
Inc., McLean, Virginia. January 1974.
The Urban Systems Model (USM) is a Lowry-type model which incor-
porates the entropy-maximizing formulation developed by A. G. Wilson.
The model consists of an integrated set of activity system sub-
models which distribute population and service employment to small areas
in a metropolitan region as a function of: the transportation cost (in
terms of time or money) of traveling to the small area; the intrinsic
attractiveness of the small area to population or service employment;
the competitive attractiveness of all other such small areas; and the
activity holding capacity of each small area.
Assuming regional projections of population, primary and service
employment, and a small area distribution of primary employment, the USM
operates iteratively to distribute increments of employment from work
place to residential locations and of service demand from residences and
work places to service centers. This iterative procedure converges on
the regional population and service employment control totals. After
regional convergence is attained and small area holding capacities are
satisfied, small area densities, accessibilities, and market potentials
are calculated for each activity.
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In addition to the calculation of the aforementioned indices, the
USM has the optional capbility of calculating the following environmental
indices:level of sewer service per resident and per primary employee;
level of water service per resident and per primary employee; mobile source
emissions (i.e., highway and transit) by district; mobile source air
pollution exposure indices (i.e., highway and transit) by district; and
noise pollution exposure levels from large stationary sources (e.g., air-
ports) by district.
The USM is a static equilibrium model, which is operated recursively
(generally in ten-year periods) to predict activity distributions for
future points in time. The temporal dimension is treated implicitly in
the model via the usage of logged residential and service employment
attraction indices. The model may also be applied in a semi-dynamic
form to distribute the growth in activity during the forecast interval.
The USM has been calibrated and applied in the North Central Texas
(Dallas-Ft. Worth) and Baltimore regions, is being calibrated for
Kalamazoo, Michigan, and is also be adapted for application at the
statewide level in Connecticut.
2
Correlation coefficients (R ) and root mean square error are
calculated by the USM and provide statistical measures of the overall
quality of calibration results. The calibration procedure also provides
a comparison of the actual and estimated levels of population, service
employment, and total employment by small area. Analysis of the North
Central Texas calibration results show close correlation between actual
and estimated population, service employment, and total employment and a
good bit between the actual and estimated distributions of percent work
trips against travel cost.
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Wilson, A. G. Entropy in Urban and Regional Modeling. London, Pion
Limited, 1970.
This reference represents a synthesis of the work done by A.G. Wilson in
developing an entropy maximizing approach to spatial interaction within
an urban system. Wilson addresses the specific relationship of the
entropy-maximizing approach to transport models and locational analyses.
The gravity model, which has usually been derived thorugh analogies
with Newtonian mechanics, is derived by Wilson using a statistical
approach. The basic gravity model he produces is shown to be applicable
in a variety of transport flow situations.
In addition, Wilson demonstrates that the entropy-maximizing approach
can be applied to locational models which describe macro-system movements.
For example, the location of retail activity and residences may be
ascertained via Wilson's approach. However, the author concedes the
maximum entropy approach is probably not suitable in projecting discrete
industrial locations.
Wilson also discusses the close relationship of the entropy-maximizing
approach to input-output economic models and utility-maximizing systems
and concludes that the theory is quite adaptable in the field of urban
and regional modeling.
Wilson, A. G. Models in Urban Planning: A Synoptic Review of Recent
Literature. Urban Studies. November 1968.
The paper presents a systems framework for the design and implemen-
tation of planning models. Wilson presents the following hierarchical
relevance tree for planning:
Policy
• Action
• Goals
• Evaluation
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Design
Plan Formulation
Design Techniques
Problem Formulation
Understanding
Systems Models
Techniques
The author suggests that the most current model building efforts
belong to the Understanding stage, but that the future development and
application of models should involve both the Design and Policy levels.
Wilson proposes that the following basic questions be addressed
during the model development phase:
• What questions is the model trying to answer?
t Which concepts are measurable?
• What variables are at least partially controlled by the planner?
• What level of analysis and disaggregation will be used?
• How will time be treated in the model?
• What behavioral theories will the model represent?
• What techniques are available for implementing the theories?
• What relevant data are available?
• How is model to be calibrated and tested?
Wilson delineates the following urban systems and discusses the most
recent modeling work in these areas: spatially aggregated population,
spatially aggregated economic, residential, workplace, physical infrastructure,
economic activity, transport, and social services.
The remainer of the paper is a review of recent modeling contribu-
tions in each of the Policy and Design categories of the planning relevance
tree.
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Wisconsin Place Classification for Transportation Planning. State of
Wisconsin, Department of Transportation, Division of Planning. January
1973.
Wisconsin has developed a framework for ranking activity centers
via a composite index of economic importance. Activity centers are
classified by the following six identifiers: urbanized area, metro-
politan center, regional center, district center, area center, and
special center.
The classification procedure is based on the activity center ranking
as determined by the following variables: full valuation, sales tax,
population, employment, selected services, retail sales, and wholesale
trade.
The place classification methodology has been applied in ranking
Wisconsin activity centers in 1966 and has been updated for 1970. These
rankings have been used in determining the level, location, and type of
airports and highways needed in the prime market centers of the state.
It is anticipated that the place classification will also be useful in
the development of a statewide development and/or land use plan.
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TECHNICAL REPORT DATA
(I'lcase read Instructions on the reverse before completing)
REPORT NO
TITLE AND SUBTITLE
Guidelines for Air Quality Maintenance Planning and
Analysis Volume A: Land Use and Transportation
Considerations
5 REPORT DATE
August 1974
6 PERFORMING ORGANIZATION CODE
RECIPIENT'S ACC6SSIOI»NO
AUTHOR(S)
8. PERFORMING ORGANIZATION REPORT NO.
Alan M. Voorhees and Associates, Inc.
PERFORMING ORGANIZATION NAME AND ADDRESS
Alan M. Voorhees and Associates, Inc.
West gate Research Park
McLean, Virginia 22101
10 PROGRAM ELEMENT NO.
11 CONTRACT/GRANT NO
68-02-1388
2. SPONSORING AGENCY NAME AND ADDRESS
U.S. Environmental Protection Agency
Office of Air and Waste Management
Office of Air Quality Planning and Standards
Research Triangle Park, N.C. 27711
13 TYPE OF REPORT AND PERIOD COVERED
Final
14 SPONSORING AGENCY CODE
5 SUPPLEMENTARY NOTES
Part of a 12 Volume series
6. ABSTRACT
This report has been prepared to assist state and local air pollution control
agencies in utilizing land use and transportation plans in preparing Air Quality
Maintenance Plans. An overview of general methods and practice in land use and
transportation planning describes and discusses the development and uses of com-
prehensive plans and 3-C plans. General approaches are offered for considering
air quality maintenance in the comprehensive planning process and for evaluating
impacts of land use and air quality plans and policies. Information, organization
and analytical technique necessary for relating land use and transportation to
air quality are discussed. Appendices include a review of the state-ot-the art
for quantifying the relationship of land use and transportation plans to air
quality, a review of studies relating land use and transportation to air quality,
and an annotated bibliography of activity allocation procedures.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
Land Use
Planning and Zoning
Local Government
Air Pollution Control Agencies
Transportation
b.IDENTIFIERS/OPEN ENDED TERMS
Air Quality Maintenance
Plans
COSATI I icld/Group
IS DISTRIBUTION STATEMENT
19 SECURITY CLASS (This Report)
Unclassified
21 NO OF PAGES
127
20 SECURITY CLASS (This page)
Unclassified
EPA Form 2220-1 (9-73)
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