Technical Support Report for Regulatory Action
Regional Air Quality Impact of Motorcycles
August, 1975
Notice
Technical support reports for regulatory action do not necessarily
represent the final EPA decision on regulatory issues. They are in-
tended to present a technical analysis of an issue and conclusions and/.
or recommendations resulting from the assumptions and constraints of that
analysis. Agency policy constraints or data received subsequent to the
date of release of this report may alter the conclusions reached.
Readers are cautioned to seek the latest analysis from EPA before using
the information contained herein.
Emission Control Technology Division
Office of Mobile Source Air Pollution Control
Office of Air and Waste Management
U.S. Environmental Protection Agency
-------
Abstract
The hydrocarbon, carbon monoxide, and oxide of nitrogen emission
contributions of motorcycles are compared with the emission contri-
butions of light duty vehicles, light duty trucks, and heavy duty
vehicles nationwide and for six different air quality control regions
(AQCRs). The AQCRs were selected as representative of those regions
having trouble meeting national ambient air quality oxident and/or
carbon monoxide standards. The analysis indicated that uncontrolled
motorcycles alone are a relatively small percentage of the present
total mobile source emissions in all AQCRs emissions. However, uncon-
trolled motorcycles do represent a significant percentage of the maximum
allowable emissions in the AQCRs assessed. As controls of other mobile
sources (namely light duty vehicles) become effective, the motorcycles
if left uncontrolled would make a significant contribution to the air
pollution problem. This holds true in each of the six AQCRs examined
in this report and is especially^ significant at high altitudes.
Prepared by
Prepared by
Project Manager
Motorcycle Regulations
wision Director fr"
Emission Control ^
Technology Division
Distribution: D. Alexander
E. Brune
T. Cackette
J. P. DeKany
C. L. Gray
D. Hardin
K. Hellman
W. Houtrnan
T. Huls
R. Jenkins
G. Kittredge
E. Rosenberg
J. Rothhaar
R. Stahman
E. 0. Stork
G. Thompson
M. Williams
G. Forbes
-------
Statement of Problem
Before a new or revised regulation package is proposed, three
questions need to be carefully considered. First, the source addressed
in the regulation of interest needs to be evaluated to determine
whether it contributes a significant amount of emissions to the total
emission inventory. Second, the improvement in air quality as a result
of the proposed action must be evaluated. The air quality improvement
must be considered relative to air quality improvements which can be
obtained through alternative control strategies. Third, the cost of
obtaining the air quality improvement must be computed and compared with
alternative strategy costs on a cost per weight of pollutant removed
basis.
The EPA Environmental Impact Statement (EIS) for motorcycles has
considered each of these questions. However, most analyses to date
have focused on only two geographic scenarios, nationwide and the
LA AQCR. The national emission inventory case has been examined in de-
tail. This case is useful in gaining a general perspective of the problem.
However, the national case contains data from regions which have no prob-
lem meeting ambient air quality standards as well as regions which are
borderline cases and those that are quite far away from achieving the
desired ambient air quality levels. Therefore, regional examination of
the air quality implications of a strategy are necessary in order to
evaluate.the potential strategy benefits where control is most needed.
The intent of this paper is to assess the extent of the motorcycle
contribution to the total mobile source emission inventory in a range
of AQCRs which do not currently meet the National Ambient Air Quality
Standards and which are expected to continue to have trouble meeting
the NAAQSs in the 1975-1990 time frame. The regions selected are:
Salt Lake City, Houston, Phoenix/Tuscon, Denver, Los Angeles and
New Jersey. The national case is included for comparison. All cases
are based on the most up-to-date input data.
This paper does not extend the analysis to address the tons of
improvement and cost effectiveness of motorcycle control versus alter-
native control strategies on a region by region basis. Although such
an extension would be useful and will be performed in the future for
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selected regions, as a first cut approximation, the national figures
for cost effectiveness and quality of control which can be achieved
are not expected to change the ranked order of various control
strategies. (This national analysis exists in the present EIS.) . The
purpose of this analysis is limited to an assessment of the regional
air quality impact of Motorcycles.
Discussion
The methodology used to compute vehicle emissions from a given
source in a given calendar year is stated in the following equation,
12
Emissions (tons) = (.£, e. m.) c
where,
e is the emissions (gm/mile) in the calendar year of interest by vehicles
that are i years old.
m. is the mileage in the calendar year of interest by vehicles that are
i years old (miles per vehicle times number of vehicles),
c is a conversion factor to convert total grams to total tons.
By computing emissions in tons for each mobile source for each
calendar year, the percent of total mobile source emissions attributed
to individual sources can be assessed.
Appendix I gives a detailed description of where the input data on
emission rates by model year and age, vehicle mix by age, mileage
accumulation by age, and vehicle miles travelled including growth
rate estimates were obtained for each mobile source and each of the
geographic regions.
Tables 1 to 7 present the percentage impact of motorcycles to the
total mobile source HC and CO inventory as a function of calendar year
for each of the geographic regions. The HC inventory includes the
crankcase and evaporative HC emissions from LDVs, LDTs, and HDVs. No
evaporative or crankcase emissions are included for motorcycles since
motorcycle evaporative and crankcase emissions' have not been well
characterized.* The tables are based on the assumption that the following
*Limited engineering estimates performed by Southwest Research Institute
indicate that for 4-stroke motorcycles, evaporative and crankcase hy-
drocarbons are approximately thirty percent of exhaust hydrocarbons. For
2-stroke motorcycles, evaporative hydrocarbons are approximately two
percent of exhaust hydrocarbons.
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-3-
standards will be in effect:
1. Light Duty Vehicles - The 1975 interim standards are in effect
until 1977. In 1977, the 1975 interim HC and CO standards of HC =
1.5 grams/mile and CO = 15. grams/mile will remain in effect. The
NO standard will be 2.0 grams/mile. Beginning in 1978, light duty
X
vehicles are assumed to meet statutory HC and CO levels. A gradually
decreasing schedule of NO control has been assumed (as discussed in
AP- 42, supplement 5). It is assumed that evaporative emissions
will be reduced to .7 grams/mile starting in 1979.
2. Light Duty Trucks - In the analysis, light duty trucks are
defined as all trucks with gross vehicle weights below 8500 pounds.
Until 1978, trucks below 6000 pounds are assumed to be regulated
at levels of HC = 2.0 grams/mile, CO = 73 grams/mile, and NO =
6.9 grams/mile. In 1978, all light duty trucks are assumed to
be regulated to standards of HC = 1.7 grams/mile, CO = 18 grams/
mile and NO =2.3 grams/mile. These standards are in the process
X
of being proposed. No further reductions for LDTs have been assumed,
although evaporative emissions are assumed to be reduced to .7 grains/
mile beginning with the 1979 model year.
3. Heavy Duty Vehicles - In this analysis, heavy duty vehicles are
defined as all trucks with gross vehicle weights above 8500 pounds
GVW. Until 1978, these trucks are assumed to be regulated at levels
of HC + NO = 16 grams/brake horsepower-hour and CO = 40 grams/brake
X
horsepower hour. These levels represent approximately 53%, 32%, and
4% HC, CO, and NO control from uncontrolled levels for gasoline
X
trucks and 26%, 0%, and 0% control from uncontrolled levels for
Diesel trucks.
In 1978, heavy duty trucks are assumed to be regulated at levels
equivalent to 75%, 41%, and 20% control from uncontrolled levels
for gasoline trucks and 26%,- 0%, and 9% control from uncontrolled
levels for Diesel trucks. No further control of heavy duty trucks
has been assumed for post-1978.
4. Motorcycles - No control of motorcycles has been assumed.
To give a range on the -potential impact of uncontrolled motorcycles
in 1990, two other cases have been hypothesized regarding standards.
Case I assumes that light duty vehicles remain at interim 1977 levels until
1990, all other standards remain as stated above. This case simulates
the lowest expected control level for mobile sources in 1990. Case II
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-4-
assumes that light duty trucks, and heavy duty gasoline trucks have
HC, CO, and NO reductions equivalent to the light duty statutory
X
reductions and heavy Diesel trucks have NO reductions equivalent to
X
light duty vehicle statutory reductions. These reductions are assumed
to be implemented in early 1980 so that by 1990, the entire mobile source
population would be controlled to very stringent levels. Table 8 gives
the percent motorcycle contribution in 1990 for each of the geographic
.•regions assuming low and high mobile source control options.
Appendix 2 presents a graphical illustration of the motorcycle
emission inventory for the national case and for Los Angeles as a function
of calendar year. Included on the graph are the projected emission
inventories if the proposed interim standards and the proposed final
standards are adopted for motorcycles. These projections use the input
data discussed in Appendix 1.
Motorcycle emissions can also be examined as a percentage of the
allowable ambient air quality standard. That is, the NAAQS will be
attained when total emissions from all sources, mobile and stationary,
are at a given level. This level (in tons/day or tons/year) will vary
from region to region due to differences in meterological conditions,
terrain, etc. Tables 1-8 indicate that motorcycle emissions can be
expected to be substantial contributors to total mobile source emissions
in 1990. However, projections by Office of Air Quality Planning and
Standards indicate that mobile sources will only be between twenty and
forty percent of the total hydrocarbon problem by 1990 in the regions
examined in this analysis. Calculations to determine motorcycle emissions
as a percentage of emissions allowable if standards are to be attained
indicate that in 1990 in the AQCRs examined, uncontrolled motorcycles
will be between three and twelve percent of the total allowable emissions
(mobile and stationary) if the oxident standard is to be achieved. The
details of these calculations are given in Appendix 3.
Conclusions
Many regions are expected to continue having problems meeting oxi-
dant and carbon monoxide ambient air quality standards in the 1980-1990
time frame. The six regions examined in this study are a subset of the
approximately 25 regions which have been identified as potential problem
regions. Results of emission assessments in these regions lead to the
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following conclusions:
1. Motorcycle HC and CO emissions are of equal importance in a
wide range of AQCRs.
2. The biggest potential impact of motorcycle emissions is in
high altitude areas such as Denver and Salt Lake City. With the
advent of high altitude emission regulations in 1977 for light
duty vehicles, the emission inventories in high altitude geographic
regions should show a marked decrease. High altitude regulations
have not been postulated for motorcycles. Therefore, to the
extent that altitude affects the air fuel ratios for motorcycles
and to the extent that this situation is not compensated for with
maintenance adjustments, motorcycle emissions can be expected to be
signficiantly higher in high altitude locations. Thus motorcycles
compose a larger fraction of total mobile source emissions at high
altitudes than is expected at low altitudes.
3. Until such time as light duty vehicles are controlled more
stringently than the 1975 interim levels, motorcycles remain
relatively minor contributors to total mobile source emission
inventories in all AQCRs. This is not because the emissions in
grams per motorcycle mile are low but becuase the total number
of motorcycle miles are low.
4. Motorcycles are not as significant CO contributors as they
are HC contributors. This is directly attributable to the fact
that at the present time, gasoline HDVs are expected to remain
significant CO contributors for at least the next six years.
Although the proposed interim HDV standards will reduce the HDV HC
contribution, the CO contribution cannot be significantly reduced
until a revised gasoline HDV test procedure is developed. Such an
action is at least six years away.
5. Once LDV, LOT, and HDV emissions are reduced to levels approx-
imating 95% HC and. CO control, motorcycles become major mobile
source contributors if'..they are not controlled. The currently pro-
'•i
posed motorcycle standards (interim standards in 1978 with LDV
statutory equivalent standards in 1980) would result in a 90% HC
and CO emission reduction from motorcycles by 1990. A continuation
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of the 1978 interim standards out to 1990 would reduce motorcycle
HC emission by 40% and CO emission by 15% by calendar year 1990.
(The possibility of significantly greater control exists if manu-
facturers redirect their marketing lines as a result of interim
standards.) However, these interim standards have only been pro-
posed as two year standards. Any decision to extend these standards
should be preceded by a thorough assessment of available technology
and cost effectiveness. Such an assessment will be performed in
response to the NPRM comments.
6. By 1990, the uncontrolled motorcycle contribution to the
total mobile source contribution is projected to range from 3.1 to
20.6 percent for hydrocarbons and 1.3 to 16.1 percent for carbon
monoxide. Specific values for each of the six AQCRs as well as the
national case are summarized in the following table.
1990 Uncontrolled Motorcycle Contribution as % of
Total Mobile Source Contribution
Least Stringent
LDV-1975 interim
CDT-1973 interim
HDV-1978 interim
Presently Planned
LDV-1978 statutory
LDT-1978 interim
HDV-1978 interim
Most Stringent
LDV-1978 statutory
LDT-90% reduction
HDV-90% reduction
National
Phoenix
Salt Lake City
Denver
Houston
New Jersey
Los Angeles
HC
3.2
3.2
6.9
5.2
3.8
2.4.
3.1
CO
1.7
1.8
4.0
2.5
2.1
1.3
2.0
HC
7.0
7.4
16.0
11.3
9.0
5.7
7.8
CO
3.3
3.7
7.7
4.1
4.3
2.7
4.5
HC
9.4
10.0
20.6
15.4
11.8
7.8
9.6
CO
7.6
8.7
16.1
13.1
9.8
6.2
8.7
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Table 1
Nationwide Mobile Source Emission
Projections
TOTAL EMISSIONS (in ton/yr.)
FOR
THE NATION
I
Year
Light
Duty
Vehicles
Light
Duty
Trucks
Heavy
Duty
Diesels
Heavy
Duty
Gasoline
Motorcycles
Mobile
Source
Total
Motorcycle
Percent
of Total
HC
x 10
1972
1974
1976
1978
1980
1985
1990
9.98
9.72
8.39
7.25
5.88
2.79
1.73
2.36
2.18
1.92
1.76
1.45
.858
.635
.201
.221
.229
.238
.248
.274
.303
2.37
2.23
2.04
1.87
1.57
1.09
.857
.0790
.115
.137
.159
.179
.218
.265
14.99
14.47
12.72
11.28
9.33
5.23
3.79
.53%
.79%
1.1 %
1.4 %
1.9 %
4.2 %
7.0 %
CO
x 10
1972
1974
1976
1978
1980
1985
1990
7.64
7.34
5.91
4.54
3.20
1.14
.650
1.36
1.28
1.12
.959
.736
.454
.343
.126
.138
.143
.149
.155
.171
.189
1.40
1.46
1.43
1.40
1.32
1.18
1.15
.0295
.0391
.0417
.0486
.0546
.0664
.0808
10.56
10.26
8.64
7.10
5.47
3.01
2.41
. 28%
.38%
.48%
.68%
1.0 %
2.2 %
3.3 %
NOx
1972
1974
1976
1978
1980
1985
1990
4.45
4.70
4.77
4.23
3.29
1.53
1.10
.769
.844
.881
.894
.842
.707
.618
.914
1.00
1.04
1.07
1.09
1.20
1.32
.532
.612
.760
.834
.886
.105
.117
.0017
.0019
.0019
.0022
.0024
.0030
.0036
6.67
7.22
7.45
7.03
6.11
I 3.55
3.16
.03%
.03%
.03%
.03%
.04%
.08%
.11%
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Table 2
Phoenix-Tuscon AQCR Mobile Source
Emission Projections
TOTAL EMISSIONS (in ton/yr)
For
PHOENIX-TUSCON AOCR
Year
Light
Duty
Vehicles
Light
Duty
Trucks
Heavy
Duty
Diesels
Heavy
Duty
Gasoline
Motorcycles
Mobile
Source
Total
Motorcycle
Percent
of Total
HC
x 10
1972
1974
1976
1978
1980
1985
1990
8.99
8.78
8.18
7.56
6.53
3.41
2.08
1.92
1.84
1.74
1.69
1.42
.907
.707
.0406
.0456
.0507
.0558
.0608
.0710
.0862
1.83
1.75
1.74
1.68
1.45
1.09
.926
.102
.149
.178
.198
.214
.261
.305
12.9
12.6
11.9
11.2
9.67
5.74'
4.10
.79%
1.2%
1.5%
1.8%
2.2%
4.5%
7.4%
CO
x ID'
1972
1974
1976
1978
1980
1985
1990
6.80
6.59
5.84
4.85
3.65
1.51
.758
1.11
1.08
.990
.905
.714
.492
.379
.0253
.0285
.0316
.0348
.0380
.0443
.0538
1.14
1.18
1.23
1.27
1.25
1.20
1.24
.0377
.0503
.0535
.0601
.0650
.0790
.0925
9.11
8.93
8.15
7.12
5.72
3.33
2.52
.41%
.56%
.65%
.84%
1.1%
2.4%
3.7%
NOx
x 10
1972
1974
1976
1978
1980
.....19.85
1990
3.79
4.12
4.44
4.29
3.57
1.92
1.34
.665
.718
.796
.841
.814
.765
.692
.184
.207
.230
.250
.267
.312
.378
.465
.582
.677
.776
.865
1.08
1.25
.0019
.0024
.0024
.0027
.0029
.0035
. 0041
5.11
5.63
6.15
6.16
5.52
4.08
3.66
.04%
.04%.
.04%
.04% .
.05%
.09%
.11% .
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Table 3
Salt Lake County, Utah Mobile Source
Emission Projections
TOTAL EMISSIONS (in ton/yr)
For
WASATCH AQCR
Year
Light
Duty
Vehicles
Light
Duty
Trucks
Heavy
Duty
Diesels
Heavy
Duty
Gasoline
' Motorcycles
Mobile Motorcycles
Source Percent
Total of Total
HC
x 10
1972
1974
1976
1978
1980
1985
1990
2.52
2.49
2.35
2.18
1.88
.866
.423
.529
.513
.496
.474
.383
.229
.143
.0091
.0100
.0111
.0122
.0134
.0148
.0163
.267
.242
.236
.224
.199
.150
.138
.0669
.0907
.104
.108
.112
.124
.137
3.39
3.35
3.20
3.00
2.59
1.38
.857
2.0%
2.7%
3.3%
3.6%
4.3%
9.0%
16.0%
CO
x 10'
1972
1974
1976
1978
1980
1985
1990
2.33
2.43 .
2.25
1.90
1.48
.526
.150
.373
.391
.379
.329
.257
.160
.0717
.0057
.0062
.0069
.0076
.0084
.0092
.0102
.197
.207
.218
.231
.247
.259
.284
.0284
.0319
.0327
.0340
.0353
.0390
.0431
2.93
3.07
2.89
2.50
2.03
.993
.559
.96%
1.0%
1.1%
1.4%
1.7%
3.9%
7.7%
NOx
x 10-
1972
1974
1976
1978
1980
1985
1990
5.26
6.31
7.63
7.75
6.99
4.06
2.69
.879
1.11
1.36
1.51
1.53
1.55
1.30
.412
.454
.502
.543
.584
.644
.712
.356
.460
.570
.697
.854
1.10
1.30
.0053
.0062
.0059
.0061
.0064
.0071
.0078
6.91
8.34
10.1
10.5
9.96
7.36
6.01
.077%
.074%
.058%
.058%
.064%
.096%
.13%
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Table 4
Denver AQCR Mobile Source
Emission Projections
TOTAL EMISSIONS (in ton/yr)
for
Year
1972
1974
1976
1978
1980
1985
1990
Light
Duty
Vehicles
HC
7.81
7.87
7.05
6.20
5.09
2.15
1.16
Light
Duty
Trucks
Heavy
Duty
Diesels
x 104
1.50
1.49
1.39
1.29
1.01
.607
.375
.0552
.0618
.0654
.0695
.0735
.0816
.0898
Heavy
Duty
Gasoline
Motorcycles
Mobile
Source
Total
1.63
1.58
1.50
1.38
1.17
.859
.755
CO x 105
1972
1974
1976
1978
1980
1985
1990
7.36
7.80
6.73
5.28
3.85
1.16
.429
1.04
1.12
1.06
.906
.671
.431
.184
.0345
.0386
.0408
.0433
.0459
.0509
.0560
1.20
1.29
1.30
1.34
1.37
1.44
1.56
.112
.171
.196
.212
.229
.274
.302
.0434
.0602
.0618
.0669
.0723
.0863
.0953
11.1
11.2
10.2
9.15
7.57
3.97
2.68
Motorcycles
Percent
of Total
1.0%
1.5%
1.9%
2. ,3%
3.0%
6.9%
11,3%
9.68
10.31
9.19
7.63
6.01
3.17
2.32
.45%
.58%
.67%
.88%
1.2%
2.7%
4.1%
NOx
x 10
1972
1974
1976
1978
1980
1985 '
1990
1.74
2.12
2.45
2.35
1.97
1.01
.726
.224
.313
.369
.405
.391
.399
.330
.251
.281
.297
.311
.321
.356
.392
.215
.272
.325
.383
.455
.594
.714
.00089
.00116
.00112
.00121
.00131
.00156
.00172
2.45
2.99
3.44
3.45
3.14
2.36
2.16
.04%
.04%
.03%
.04%
.04%
.07%
.08%
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Table 5
Houston-Galveston AQCR Mobile Source
Emission Projections
TOTAL EMISSIONS (in ton/yr)
for
HOUSTON-GALVESTON AQCR
Year
1972
1974
1976
1978
1980
1985
1990
1972
1974
1976
1978
1980
1985
1990
Light
Duty
Vehicles
HC
1.19
1.18
1.08
.982
.841
.400
.249
CO
9.11
8.88
7.59
6.15
4.58
1.63
.931
Light
Duty
Trucks
.204
.190
.177
.168
.144
.0833
.0654
1.21
1.15
1.02
.893
.710
.442
.375
Heavy
Duty
Diesels
x 105
.0108
.0120
. 0132
.0145
.0160
.0176
.0195
x 105
.0674
.0747
.0822
.0902
.0996
.110
.121
Heavy
Duty
Gasoline
.230
.209
.203
.188
.163
.123
.114
1.51
1.55
1.61
1.61
1.58
1.46
1.53
i
Motorcycles
.0117
.0157
.0189
.0220
.0257
.0363
.0442
.0434
.0531
.0572
.0668
.0779
.110
.134
Mobile
Source
Total
1.65
1.61
1.49
1.37
1.19
.660
.492
11.9
11.7
10.4
8.81
7.05
3.75
3.09
Motorcycles
Percent
Of Total
.71%
.97%
1.3%
1.6%
2.2%
5.5%
9.0%
.36%
.45%
.55%
.75%
1.1%
2.9%
4.3%
NOx
x 10
1972
1974
1976
1978
1980
1985 .
1990
5.31
5.70
6.13
5.73
4.71
2.20
1.58
.763
.827
.916
.945
.908
.754
.704
.491
.544
.599
.644
.696
.768
.848
.669
,851
1.00
1.13
1.24
1.38
1.53
0.0022
0.0025
0.0026
0.0030
0.0035
0.0049
0.0060
7.24
7.92
8.65
8.45
7.56
5.11
4.67
.03%
.03%
.03%
.04%
.05%
.12%
.13%
-------
Table 6
New Jersey Mobile Source
Emission Projection
TOTAL EMISSIONS (in ton/yr)
for
N.J..Portion of N.Y.,N.J., Conn AQCR
Year
1972
1974
1976
1978
1980
1985
1990
1972
1974
1976
1978
1980
1985
1990
Light
Duty
Vehicles
HC
2.76
2.56
2.22
1.91
1.54
.732
.456
CO
2.11
1.93
1.56
1.20
.840
.299
.170
VI/->
Light
Duty
Trucks
X ]
.484
.435
.383
.345
.277
.165
.125
x
.285
.259
.220
.184
.138
.0878
.0699
Heavy
Duty
Diesels
LO5
.0249
.0260
.0270
.0281
.0293
.0323
.0356
LO6
.0156
.0162
.0169
.0175
.0183
.0202
.0222
,5
j Heavy
Duty
Gasoline
.573
.492
.454
.401
.333
.244
.210
.357
.347
.340
.325
.304
.277
.281
i Motorcycles
•,
.00950
.0138
.0178 1
.0208 \
.0243
.0357
.0505
1
.00355 j
.00468 '•
.00544
.00634
.00740
.0109
.0154
Mobile
Source
Total
3.85
3.53
3.10
2.70
2.20
1.21
.877
2.77
2.56
2.14
1.73
1.31
.695
.559
Motorcycle
Percent
of Total
.24%
.39%
.57%
.76%
i
1.1%
2.9%
5.7%
.12%
.18%
.25%
.36%
.56%
1.6%
2.7%
1972
1974
1976
1978
1980
1985
1990
1.23
1.24
1.26
1.11
.864
.402
.289
. .176
.179
.188
.185
.168
.144
.130
.113
.118
.123
.126
.129
.142
.157
.143
.177
.197
.214
.225
.256
.283
. 00019
.00022
.00024
. 00028
.00033
.00049
.00069
1.67
1.71
1.77
1.64
1.39
.944
.860
: . 011%
.013%
.014%
.017%
.024%
.052%
.080%
-------
Table 7
Los Angeles AQCR Mobile Source
Emission Projection
TOTAL EMISSIONS (in ton/yr)
T«r
Light
Duty
Vehicles
for
( LA AQCR
Light
Duty
Trucks
Heavy
Duty
Diesels
Heavy
Duty
Gasoline
Motorcycles
Mobile
Source
Total
Motorcycle
Percent
of Total
HC
x 10
1972
1974
1976
1978
1980
1985
1990
1972
1974
1976
1978
1980
1985
1990
.433
.406
.367
.309
.244
.122
.0968
C
.369
.325
.266
.201
.143
.0488
.0320
.0660
.0606
.0572
.0505
.0436
.0281
.0208
0
.0409
.0377
.0348
.0289
.0245
.0158
.0114
.00568
.00598
.00634
.00669
.00709
.00801
.00908
x 107
.00354
.00373
.00395
.00418
. 00443
.00500
.00566
.0586
.0522
.0451
.0378
.0316
.0242
.0246
.0376
.0373
.0365
.0350
.0331
.0310
.0330
.00736
.00847
.00971
.0101
.0105
.0116
.0128
.00274
.00286
.00294
.00306
.00319
.00352
.00389
.571
.533
.485
.414
.337
.194
.164
.454
.407
.344
.272
.208
.104
.0859
1.3%
1.6%
2.0%
2.4%
3.1%
6.0%
7.8%
.60%
.70%
.85%
1.1%
1.5%
3.4%
4.5%
NOx
x 10
6
1972
1974
1976
1978
1980
1985
1990
.200
.203
.196
.172
.135
.0670
.0541
.0235
.0245
.0252
.0259
.0246
.0227
.0204
.0258
.0272
.0280
.0293
.0311
.0351
.0397
.0148
.0183
.0209
.0230
.0253
.0294
.0333
.000140
.000137
.000132
.000137
. 000143
.000157
.000174
.264
.273
.270
.250
.216
.154
.148
.05%
.05%
.05%
.05%
.07%
.10%
.12%
-------
Table 8
1990 Motorcycle Emission Contribution to total Mobile Source Contribution
by Control Strategy
(Motorcycle Contribution expressed as % of Total)
Strategy JV
123
National
^
Phoenix
Salt Lake City
Denver
Houston
New Jersey
Lqs Angeles
HC
3.2
3.2
6.9
5.2
3.8
2.4
3.1
CO
1.7
1.8
4.0
2.5
2.1
1.3
2.0
HC
7.0
7.4
16.0
11.3
9.0
5.7
7.8
CO
3.3
3.7
7.7
4.1
4.3
2.7
4.5
HC
9.4
10.0
20.6
15.4
11.8
7.8
9.6
CO
7.6
8.7
16.1
13.1
9.8
6.2
8.7
I/Strategy 1 is the least stringent mobile source control strategy. It assumes
light duty vehicles remain at 1975 levels; light duty trucks are controlled
to light duty vehicle interim equivalent levels; heavy duty vehicles are
controlled to levels slightly less stringent than those proposed for 1978.
No further control is' assumed
Strategy 2 assumes that levels currently proposed will in fact be implemented.
Light duty vehicles will go to statutory levels in 1978. Light duty trucks and
heavy duty trucks will be regulated as in strategy 1.
Strategy 3 is the most stringent mobile source control option. Light duty vehicles
will be controlled to statutory in 1978. Light duty trucks will achieve the same
reductions in emissions (from a pre-control baseline) as LDVs starting in 1980 and
heavy duty gasoline vehicles will achieve the same reductions in emissions as
LDVs starting in 1981. LDTs and ,HDVs will have interim control as described in
strategies 1 and 2.
-------
Appendix I: Usage Data
-------
A-l
DATA SUMMARY FOR THE NATION
I. Emission Rates:
A. Motorcycles - EPA Data, SwRI Data, and Motorcycle Manufacturers' Data
were used to obtain a linear regression of emission rate vs. displacement.
(Separate regressions for 2-stroke and 4-stroke engines).Using these re-
gressions an emission rate for 4 engine classes was obtained by weighting
the emission rates according to the fraction of motorcycles in each sub-
class. Gallup Data were used for this purpose; they were divided into
8 displacement classes and into 2-stroke and 4-stroke.
Interim emission rates were based on the proposed interim standards.
It was assumed that where moderate control was required to meet HC and CO
standards, the NOx emission rate would rise 3 times (300%), and where
significant control was required to meet HC and CO standards the NOx
rate would increase 5 times (500%). This was based on engineering
calculations,
Final emission rates are assumed to be at the LDV statutory levels.
Emission Rates gm/km
Uncontrolled
Interim
Statutory
Engine Class
2S < 170cc
2S > 170cc
4S *: 170cc
4S > 170cc
HC
8.3
12.0
.9
1.7
CO
14.5
18.1
11.7
23.4
NOx
.025
.025
.15
.15
HC
5.0
7.29
.9
1.7
CO
14.5
16.8
11.7
16.7
NOx
.075
.125
.15
.45
HC
.25
.25
.25
.25
B. Other Vehicles - The low altitude emission rates in AP-42
CO
2.1
2.1
2.1
2.1
NOx
.25
.25
.25
.25
were used
II. Vehicle Mix ..By Age
A. Motorcycles - The Gallup Data were used to obtain the number of
motorcycles of each model year for the four engine classes. (Note, this
breakdown did not appear in the published report, but was obtained from the
Gallup Data on file). This distribution was assumed to remain constant
for all calendar years.
-------
A-2
III.
IV.
Fraction of Motorcycle Population as Function of Age
Engine / Age
2S < 170cc
2S 7 170cc
AS -C 170cc
AS > 170cc
0
.058
.123
.083
.126
1
.237
.218
.16A
.2A3
2
.212
.2AA
.131
.192
3
.123
.155
.157
.157
A
.114
.081
.138
.086
5
.07A
.062
.069
.052
6
.OA8
.047
.057
.039
7
.037
.025
.061
.029
8
.035
.023
.050
.02A
9
.035
.007
.OA(
.021
V.«at
10
.012
.006
.015
.005
Lonaj_
11
-
.003
.011
.009
Average
12 +
.01A
.006
.018
.016
B> Other Vehicles. The national average values in AP-A2 were used.
Mileage Accumulation Rate
A. Motorcycles - Data on mileage accumulation were obtained from the EPA
Standards Development and Support Branch report on "Motorcycle Useful Life".
From that data approximate rates of mileage accumulation were obtained as a
function of age. Only two engine classes were used (See Figure 1).
Mileage Accumulation Rate By Age (Miles/year) (National Average)
„ . Age(yr)
Eneine ° J „
< 170 cc
> 170 cc
2160
A3A2
1
1685
338A
2
1168
2390
3
1084
2317
A
1000
22A5
5
917
2173
6
833
2101
7
750
2030
8
666
1958
9
583
1885
10
A99
1813
11
A15
17A1
12+
A15
17A1
B. Other Vehicles - The national average values in AP-A2 were used.
Vehicle Miles -Traveled
A. Motorcycles - Since no accurate VMT estimates are available for the
entire motorcycle population, VMT's were calculated as follows: A weighted
average VMT value per motorcycle was obtained using the above data on
mileage accumulation and the vehicle mix data. These values are shown below.
Average Miles Per Year (National Average) -
Engine
Miles
2S<170cc
1211.
2S>170 cc
2765.
AS<.170 cc
1153.
AS > 170cc
2778.
Total VMT's were obtained by multiplying the number of, motorcycles in each
: class times the average VMT value. The number of motorcycles in each class
was calculated using total motorcycle registrations (from Dept. of Transporta-
tion Data) and assuming a breakdown as indicated by Gallup Data and by
R. L. Polk Co. Data, as shown below.
-------
A-3
Fraction of Motorcycles in Each Engine Class
Engine
Year/
1971.
1972
1973
1974
1975
1976+
2S<170cc
.17
.17
.19
.21
.22
.23
2S>170cc
.24
.24
.255
.27
.29
.31
4S170
.41
.41
.40
.39
.37
.35
Estimate
R.L.Polk Data (1972)
Estimate
Gallup Data (1974)
(All Model Yrs)
Estimate
Gallup Data (1974)
(72-74 Model Yrs Only)
Future VMT's were calculated assuming the following growth rates:
8% Until 1980
4% Thereafter
(Note: Between 1969 and 1974 Motorcycle Registrations have increased at
least 14% each year, nationwide. A slowing of this growth rate is occurring
in 1975 and is expected to continue.)
B. Other Vehicles - Department of Transportation statistics were used to
obtain total VMT's. The national average fraction of VMT's by each vehicle
type as in AP-42 was used to determine VMT's for each type of vehicle
(LDV's - 80.4%, LDT's - 11.8%, HD Diesels - 3.2%, HD Gas - 4.6%) Future
VMTs were calculated assuming a growth rate of 2% per year.
-------
A-4
DATA SUMMARY FOR PHOENIX - TUSCON AQCR
I. Emission Rates
A. Motorcycles - The Emission Rates as shown on A-l were used.
B. Other Vehicles - AP-42 low altitude emission rates were used.
II. Vehicle Mix By Age
A. Motorcycles - It was assumed that because of climate similarities
the Gallup Data for Los Angeles would more closely approximate the
vehicle mix than would national average data. Unfortunately the
California data were not broken down into engine classes. The
California data for all motorcycles were compared with the national
f ••
data for all motorcycles (see Fig. 3) !Using Fig. 3 as a guide the
national distributions for each engine class were altered to reflect
the same differences as the distributions for all motorcycles.
Fraction of Motorcycles by Age (Warm Climate)
Engine/ Age
2S < 170cc
2S > 170cc
4S < 170cc
4S "> 170cc
0
.042
.090
.060
.090
1
.150
.140
.100
.150
2
.170
.200
.100
.150
3
.130
.170
.170
.170
4
.150
.110
.190
.120
5
.120
.100
.110
.080
6
.080
.080
.090
.080
7
.050
.030
.070
.050
8
.040
.030
.040
.030
9
.030
.020
.040
.030
10
.020
.010
.010
.020
11
.010
.010
.010
.010
12+.
.010
.020
.010
.020
B. Other Vehicles - The fraction of vehicles by age for the other types
of vehicles came from a variety of sources.
1)~ LDVs - The following data are from "A Transportation Control Strategy
for the Phoenix Tuscon Air Quality Area", APTD 1369 Feb. 1973.
LDV Age
Fraction
0
.059
1
.098
2
.107
3
.094
4
.088
5
.094
6
.092
7
.079
8
.071
9
056
10
.037
11
.035
12+
.090
2) LDTs - These data are from R. L. Polk Data for 1973; it was
supplied by EPA, North Carolina. The data were for all heavy duty
vehicles; they were broken down by weight class, but the breakdowns do
not follow the LDT-HDT cutoff of 8,500 Ib. The following is therefore
\
data for all trucks less than 10,000 Ib. (1973 data)
•LDV Age
Fraction
0
.088
1
.136
2
.080
3
.081
4
.079
5
.059
6
.054
7
.055
8
.049
9
.046
10
.039
11
.031
12+
.202
3) HDDs & HDGs - These data are from the same source as the IDT data, this
being for trucks greater than 10,000 Ib. It is probably not completely
-------
A-5
accurate to assume the same distribution for gas and diesel trucks,
but since the diesel HC & CO emission rates do not change and the NOx
rate changes only slightly the distribution of diesels is not an
important factor. The following distribution should fairly represent
the gasoline heavy duty distribution.
HDV Age
Fraction
0
.071
1
.102
2
.075
V
3
.078
-L7/ J r
4
.079
UJ.IN. Udl
5
.052
-o-J
6
.057
7
.057
8
.053
9
.055
10
.046
11
.036
12+
.237
III. Mileage Accumulation Rate By Age
A. Motorcycles - Gallup Data indicated motorcycles in California (warm
climate) accumulated more mileage than the national average. The Gallup
Data were not broken down into engine classes, so accumulated mileage
of all types of motorcycles in Los Angeles was compared with nation-
wide data for all types of motorcycles (Fig. ^). In the early years"
the warm climate motorcycles accumulated 1.3 times more mileage on the
average. This factor was assumed to be constant for all motorcycles in
all classes and all years. Therefore the table below was obtained by
multiplying national average values times 1.3.
Mileage Accumulation Rate By Age (Warm Climate)
Engine /Age
<170 cc
7170 cc
0
2808
5644
1
2190
4399
2
1518
3107
3
1409
3012
4
1300
2919
5
1192
2825
L 6
1082
2731
7
975
2639
8
865
2545
9
757
2451
10
649
2357
11
540
2263
12+
540
2263
B. Other Vehicles - National average values in AP-42 were used.
IV. Vehicles Miles Traveled
A. Motorcycles - Using the warm climate accumulated mileage data, the
following weighted averages of yearly VMT were calculated
Average Miles Per Year
Engine
Miles
2S«£. 170cc
1442.
2S>170cc
3375.
'Warm Climate)
4S < 170cc
1405.
4S > 170cc
3338.
These average yearly mileage figures were multiplied by the number of
motorcycles in each class to obtain total VMT values for each engine
class. The total number of motorcycles registered in Arizona is
available from Department of Transportation statistics. A breakdown
of registrations by counties was available for 1972 (from Arizona High-
way Department). In 1972 81% of Arizona's motorcycles were registered
in the Phoenix-Tuscon AQCR. This was assumed to remain constant.
-------
A-6
The breakdown between engine classes was assumed to be the same as
the national average.
Future VMTs were calculated assuming the following growth rates:
8% until 1978. At that time there will be approximately
4 motorcycles per 100 people in the population.
4% until 1989. 5 motorcycles per 100 people.
2% thereafter.
Since 1969 motorcycle registrations have increased between 14-26%
per year.
B. Other Vehicles - EPA North Carolina provided data from the Arizona
Highway Department on total VMTs for each county in Arizona in 1972.
Based on data in "A Transportation Control Strategy for the Phoenix-
Tuscon AQ Area", APTD 1369, Feb. 1973. The fraction of VMTs by each
type vehicle, was assumed to be:
Vehicle
LDVs
LDTs
HDDs
HDG
% of VMTs 82.7% 12% .8% 4.;
From the same source came the basis of growth estimates for future
VMTs:
5% Until 1980
3% Thereafter
DATA SUMMARY FOR SALT LAKE COUNTY. UT
I. Emission Rates
A. Motorcycles - Salt Lake City is at relatively high altitude, and
while altitude effects on motorcycle emissions are unknown it was
assumed the uncontrolled motorcycle emission rates at high and low
altitude would be in the same ratio as LDV emission rates at high
and low altitude. These ratios for uncontrolled LDVs are:
High Alt/ : HC = 4 co = NQx = <62
Low Alt
Applying these to motorcycles gives the following
High Altitude Mo
gi^km
HC
CO
NOx
2S < 170cc
12.0
21.8
.015
B. Other Vehicles - The hi]
2S>170cc
17.4
27.2
.015
;h altitude emis
4S<170cc
1.3
17.6
.09
4S>170cc
2.5
35.1
.09
sion rates in AP-42 were used.
-------
A-7
II. Vehicle Mix By Age
A. Motorcycles - National average values were used.
B. Other Vehicles-
1; LDVs - Data from "Transportation Cuntj.olo to Reduce llotcr
Vehicle Emissions in Salt Lake City, Utah," APTD 1445, Dec. 1972;
was used.
LDV Age
Fraction
0
.073
1
.085
2
.096
3
.092
4
.086
5
.091
6
.093
7
.081
8
.073
9
.062
10
.042
11
.035
12+
.090
2) LDTs - Polk Data supplied by EPA, N.C. were used. The
following is actually the distribution of trucks less than
LDT Age
Fraction
0
.100
10,000
1
.126
Ib. ir
2
.086
i Salt
3
.076
Lake C
4
.082
ounty .
5
.065
(1973 c
6
.055
ata)
7
.055
8
.051
9
.048
10
.040
11
.034
12+
.183
3) HDDs & HDGs - Polk Data for all trucks greater than
10,000 Ib. for Salt Lake County (1973 Data)
HDV Age
Fraction
I. Mileage
0
.099
1
.120
2
.086
3
.083
4
.085
Accumulation Rate By Age
5
.061
6
.059
7
.054
8
.049
9
.048
10
.040
11
.034
12+
.183
A. Motorcycles - National average mileage was used.
B. Other Vehicles - National average mileage was used.
IV. Vehicle Miles Traveled
A. Motorcycles - VMTs were calculated using national average miles
per year values. Total motorcycles registered in Salt Lake County
were known for 1973 (Utah Highway Dept. Statistics). This was 48%
of Utah's registered motorcycles. This ratio was assumed to remain
constant. National average engine class breakdown was assumed. Future
growth was assumed to be only 2% per year because of the large
motorcycle population.
B. Other Vehicles - EPA, N.C. provided data on total VMTs in each
Utah County in 1972. These data were from an EPA contractor's
measurements.
The VMT breakdown between vehicle types was assumed to be
LDV-85%,LDT - 11.75%, HDD -.81%, HDG - 2.4%.
-------
A-8
This is based on data contained in "Transportation Control to Reduce
Motor Vehicle Emission in Salt Lake City, Utah" APTD 1443, Dec. 1972.
Future VMTs were calculated assuming growth of:
5% per year until 1980 and
2% thereafter
The 5% figure is based on data in the same reference.
DATA SUMMARY FOR DENVER AQCR
I. Emission Rates
A. Motorcycles - High altitude emission rates were used.
B. Other Vehicles - High altitude emission rates as in AP-42 were used.
II. Vehicle Mix By Age
A. Motorcycles - National average values were used.
B. Other Vehicles
1) LDVs - National averages were used from AP-42.
2) LDTs - Polk Data for trucks less than 10,000 Ib for the four
LOT Age
Fraction
0
.062
1
.139
2
.093
3
.083
4
.083
5
.060
3) HDDs & HDGs - Polk Data
for the four most populous
HDV Age
Fraction
0
.081
1
.127
2
.080
3
.052
4
.067
5
.060
6
.055
7
.053
>I\ WCJ.U
8
.047
useu .
9
045
(19^
10
.037
'3 Data)
11 | 12+
.034 |.209
for vehicles greater than 10,000 Ib
counties in the Denver AQCR were used.
6
.049
7
.057
8
.052
9
052
10
.043
11
.039 .
12+
.240
III. Mileage Accumulation ;Rate By Age
A. Motorcycles - National averages were used.
B. Other. Vehicles - National averages were used from AP-42.
IV. Vehicle Miles Traveled
A. Motorcycles - VMTs were calculated using the following data:
National average miles per year values ; total motorcycle registra-
tions in Denver AQCR (From Colorado Highway Dept. for 1972, and
assuming the same ratio of 54% of Colorado's motorcycles in Denver
AQCR for other years)
Growth Rates of:
4% until 1985 (5 motorcycles per 100 people)
2% thereafter
-------
A-9
(Motorcycle Registrations in Colorado have increased between
29% and 16% per year since 1968)
National average breakdown of engine classes
B. Other Vehicles - EPA, N.C. provided data on total VMTs by county.
The base value used was estimated VMTs for the year 1973 from the
EPA contractor.
The national average urban VMT breakdown was used.
IDV - 84%, LDT 10%, HDD - 1.5%, HDG 4.5% (From M. Williams)
Estimated growth rates were
3% until 1980
2% thereafter
(Guesses)
DATA SUMMARY FOR HOUSTON - GALVESTON AQCR
I. Emission Rates
A. Motorcycles - Low altitude emission rates were used.
B. Other Vehicles - Low altitude emission rates in AP^-42 were used.
II. Vehicle Mix By Age
A. Motorcycles - The warm climate vehicle mix was used
B. Other Vehicles
1) LDVs - National average values in AP-42 were used.
2) IDTs - Polk Data for all trucks under 10,000 Ib in the four
most populous counties in the Houston-Galveston AQCR were
used: (1973 Data)
LDT Age
Fraction
0
.121
1
.136
2
.103
o
.095
4
.098
5
.081
6
.069
7
.064
8
.055
9
.041
10
.029
11
.023
12+
.085
3) HDDs & HDGs - Polk Data for all vehicles greater than 10,000 Ib.
in the four most populous counties in the Houston-Galveston
(1973 Data)
H&V Age
Fraction
0
.114
1
.131
2
.108
3
.107
4
.111
5
.080
6
.069 i
7
.064
8
.052
9
.038
10
.027
11
.021
12+
.078
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A-10
III. Mileage Accumulation Rate By Age
A. Motorcycles - Warm climate values were used.
B. Other Vehicles - National average values in AP-42 were used.
IV. Vehicle Miles Traveled
A. Motorcycles - VMTs were calculated using the following data:
Warm climate average miles travelled per year;
Total motorcycle registrations in Houston-Galveston AQCR (The
ratio of registrations in Houston-Galveston AQCR to registrations
in Texas was assumed to stay the same for all years: in 1972 21%
of Texas motorcycles were in the Houston-Galveston AQCR);
National average breakdown of engine classes;
Future Growth Rates of
8% until 1985 (4 motorcycles per 100 people)
4% until 1992 (5 motorcycles per 100 people)
2% thereafter (Growth has been 11-31% per yr since 1968)
B. Other Vehicles - EPA, N.C. provided data from the Texas Highway
Department giving total VMTs for each Texas county for 1972.
The National average urban VMT breakdown between types of vehicles
was used.
Growth was assumed to be
5% until 1980
2% thereafter
DATA SUMMARY FOR N*J-. PORTION OF N.Y. .- N.J. - CONN. AQCR
I. Emission Rates
A. Motorcycles - Low altitude emission rates were used>
B. Other Vehicles - Low altitude emission rates in AP-42 were used
II. Vehicle Mix By Age :
A. Motorcycles - National average values were used»
B. Other Vehicles
1) LDVs - National average values in AP-42 were used.
2) LDTs - Polk d!ata for trucks less than 10,000 Ibs in all
N.J. Counties in the NY-N.J.-Conn. AQCR were used (1973 Data)
-------
A-ll
Aae
Fraction
0
.105
1
.133
2
.099
3
.089
4
.093
L_ 5
.064
6
.060
7
.066
8
.060
9
.946
10
.038
11
.031
1
12+
.115
3) HDDs & HDGs - Polk Data for trucks more than 10,000 Ib. in
Age
Fraction
0
.078
1
.108
2
.080
3
.098
4
.102
5
.078
6
.067
7
.080
8
.062
9
.050
10
.041
11
.033
12+
.123
III Mileage Accumulation Rate By Age
A. Motorcycles. National average values were used.
B. Other Vehicles - National average values in AP-42 were used.
IV. Vehicle Miles Traveled
A. Motorcycles - The following data was used to calculate VMTs:
National average vehicle miles per year values (p 0-3)
Total N.J. motorcycle registrations (D.O.T. Statistics)
Portion of N.J. Population in the N.Y. - N.J. - Conn. AQCR (it was
assumed the motorcycle registration would be distributed as the pop-
ulation was distributed: The ratio in 1971 was .71 of N.J.
population in N.Y. - N.J. - Conn. AQCR)
National average engine class breakdown future growth rates of:
8% until 1990 (3 motorcycles per 100 people)
4% thereafter
(Since 1970 registrations have increased 8-31% per year)
B. Other Vehicles - VMTs were calculated using the following:
Total auto registrations in J.J. (D.O.T. stas)
% of population in N.Y. - N.J. - Conn AQCR (census)
National average VMT per year per car (AP-42)
National average urban breakdown of VMTs
Among type of vehicles
Growth rate of
2% per year (Guess)
-------
A-12
DATA SOURCES FOR LA AQCR ANALYSIS
I. Emission Rates
A. Motorcycles - The basic low altitude values were used.
B. Other Vehicles - The values in AP-42 for California were used.
II. Vehicle Mix. By Age
A. Motorcycles - The "Warm Climate" mix was used
B. Other Vehicles - National average values were used (AP-42)
III. Mileage Accumulation Rate By Age
A. Motorcycles - The "Warm Climate" values were used
B. Other Vehicles - National average values were used (AP-42)
IV. Vehicles Miles Traveled
A. Motorcycles - The following data were used to calculate VMTs: Total
registrations in LA AQCR (From EPA paper by T. Comfort). National
average engine class mix, warm climate average mileage accumulation
rates, and an assumed growth rate of 2%.
B. Other Vehicles - The following data were used to calculate VMT's:
Total VMTs in LA AQCR (From "Transportation Control Strategy Development
for the Metropolitan Los Angeles Region", APTD - 1372, Dec. 1972, p 98)
fraction of VMT's by M. Williams; growth rates as indicated in the above
EPA report.
-------
10 Miles
30 I
20 .
10 -
30
20 -
10 -
Figure 1
Accumulated Mileage vs. Age
>170cc
1 2 3 45 6 78 9 10 11 12 Age (years)
Figure "2~
Accumulated Mileage vs. Age
Note: This was for All
Motorcycles
Polynomial Regression of Gallop
Nation Miles=2407+(1338xAge)-(4.76xAge2)
r = .973
Calif. Miles=2331+(2593xAge)-(159xAge )
r = .764)
1 2
67 8 9 10 11 12
-------
20 -
10 -
Figure 3
of Motorcycle Population vs. Age
Nation (Actual Data)
Calif. (Third Order Curve Fit)
% = .095 Age3 - 1.69 Age2 +
6.51 Age + 8.37
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Appendix 2
Motorcycle Emission Inventory
Graphical Representation
-------
Figure 2-1
Projected Nationwide Hydrocarbon Exhaust
Emissions for Motorcycles
25 ,
20 -
15 -
o
CO
c
o
•H
CO
CO
•H
10 -
Interim
control only
Proposed
Final Standards
74
76
78
80 82
Calendar Year
84
86
88
90
-------
Figure 2-2
Projected Nationwide Carbon Monoxide
Emissions for Motorcycles
o
4-1
CO
c
o
•H
05
CD
•H
w
90 -
80 -
70 -
60
50 -
40 -
30 -
20
10 -
Interim
Control Only
Proposed
Final Standards
74 76
78 80
82 84
Calendar Year
86
88
-------
r.H
M
td
0)
o
4J
co
c
o
•H
CO
CO
•r-l
a
w
Figure 2-3
Projected Nationwide Oxides Of Nitrogen
Emissions for Motorcycles
l.oH
.9 J
.8 H
.7 -I
.6 -I
,5 J
.4 "I
.3 4
Proposed
Final Standards,
Interim
Control Only
No Control
—I l I
88 90
74
76
78
80
82
84
86
Calendar Year
-------
Figure 2-4
Projected Los Angeles AQCR
Hydrocarbon Exhaust Emissions for Motorcycles
18 -
16 -
14 -
td
Q)
e
o
0)
C
O
•H
W
CO
•H
I
12 -
10 -
6 -
4 _
2 H
Interim
Control Only
Proposed
Final Standards
74
i
76
r
78
i
80
i
82
84
i
86
88
90
Calendar Year
-------
Figure 2-5
Projected Los Angeles AQCR
Carbon Monoxide Emissions for Motorcycles
40 -
30 -
rt
-------
Figure 2-6
Projected Los Angeles AQCR
Oxides of Nitrogen Emissions for Motorcycles
.5 -
Proposed
Final Standards
.4 -
1-1
cfl
0)
c
o
CO
o
•H
CO
CO
•H
e
W
.3 -
.2 -
Interim
Control Only
No Control
,1 -
74
i
76
78
80
82
84
86
88
90
Calendar Year
-------
Appendix 3
Motorcycle Emissions as a Percent of Standard
-------
Appendix 3
Motorcycle Emissions as a Percent of Standard
In order to calculate motorcycle emissions in 1990 as a percent of
the emissions allowable if the standard is to be met, it is necessary to
determine the allowable emissions at the standard. The following propor-
tion is used:
1970 ambient concentration _ 1970 emission factor
ambient standard x
where x is the total allowable emissions, mobile and stationary, if the
standard is to be met. Solving for x,
„..-,_ . . ,. ,1970 ambient concentration .
x = 1970 emission factor ( — — ).
ambient standard
The 1970 emission factor, in tons, should be the sum of the mobile and
stationary 1970 emissions in tons (or equivalent units). Since stationary
emission factors were not readily available, the following identity was
used:
in™ 4 j c *. 1970 mobile emission factor
1970 emission factor = —. r-r: rr—-.—
% mobile source contribution
The % of the total 1970 emissions attributed to mobile sources has!'been
supplied by Office of Air Quality Planning and Standards.
Data needed to comput the value of x is given below for selected
regions:
HC i. CO
Percent Concentration Percent Concentration
Mobile (ppm) Mobile (ppm)
Pheonix 49 .19 99 42
Penver 81 .28 99 33
New York/New Jersey 73 .26 99 51
Houston 41 .32
Los Angeles 69 .62 99 41
Salt Lake City — — 98 41
Ambient Standard .08 9
-------
A-2
The uncontrolled motorcycle contribution as a percent of the allowable
emissions in 1990 is:
1990 motorcycle emissions
x
The following table presents the motorcycle percentage contribution
to the allowable emissions at standard for selected regions.
Percent Allowable Emissions
Contributed by Uncontrolled Motorcycles in 1990
Region HC * CO
Pheonix 3% 5%
Salt Lake City - 7%
Denver 8% 4%
Houston 4%
New Jersey 3% 3%
Los Angeles 12% 4%
*This analysis considers total hydrocarbons, reactive and non-reactive. The
analysis has not considered reactive hydrocarbons only since the definition of
what is reactive is highly variable. Only methane is generally agreed upon
as being totally non-reactive. Other light hydrocarbons such as ethane, butane,
and acetylene may be reactive with enough time. If stationary sources and/or
light duty vehicles and trucks have significant portions of methane in their
emissions, motorcycles could contribute an even greater percentage of total
allowable emissions if the standard is to be met. Motorcycle HC emissions are
essentially one hundred percent reactive.
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