United states          Office of Transportation                              EPA420-F-05-046
    Env.ronmcrtalProtoci.cn   and Ajr Qua|jty                                    October 2005


                     77)e I/. S. Environmental Protection Agency (EPA) has developed
                     guidance for      and agencies that are involved in developing
                     implementation plans (SIPs) or transportation conformity determinations.
                     This guidance explains how these agencies can incorporate emissions
                     reductions resulting from changes in commuter trip behavior to their SIPs
                     and transportation conformity determinations.

                     The guidance explains how providing a high level of commuter benefits,
                     as defined by achievement of the Best Workplaces for CommutersSM
                     (BWC) designation, can result in decreased commuter trips, leading to
                     decreased emissions.  It also provides information on using one of the
                     tools available to quantify these reductions—a newly-revised,
                     spreadsheet-based calculator called the COMMUTER model.
                          Workplaces for CommutersSM
                    BWC is one of the voluntary programs offered by EPA's Office of Trans-
                    portation and Air Quality aimed at achieving measurable environmental

benefits in a cost-effective way, without the need for regulation. Employ-
ers qualifying to be designated as BWC must offer excellent commuter
benefits that meet the program's "National Standard of Excellence."
Voluntary programs like BWC can reduce pollution and improve air
quality through strategic partnerships with small and large businesses,
citizen groups, industry, manufacturers, trade associations, and state and
local governments.
SIP and Transportation Conformity Determinations
Commuter benefit programs like BWC can offer quantifiable emission
reductions. The guidance document describes the requirements for
seeking emissions credit for BWC-related measures in SIPs and transpor-
tation conformity determinations. While various modeling methodolo-
gies for estimating the benefits of BWC-related measures are available,
state and local agencies seeking reductions for SIPs or conformity should
engage in a consultation process with EPA regarding appropriate meth-
EPA has updated the COMMUTER model, first released in 2001, to
assist worksite transportation coordinators and local planners in estimat-
ing the impacts of commuter programs like BWC. The 2005 revision
interfaces with EPAs current MOBILE6.2 emission factor model and
adds the capacity to estimate how a commuter benefit can impact par-
ticulate matter, air toxics emissions, and fuel use and costs. Running the
model requires the user to provide information on the number of employ-
ees covered and the types of benefits offered to them. The COMMUTER
model allows users to input local-specific travel data, and emissions
factors based on a MOBILE6.2 run representing the area. The MO-
BILE6.2 look-up tables for emission factors in the COMMUTER model
can be used to provide a preliminary estimate on what reductions are
produced. If you choose to use the COMMUTER model to quantify
emission reductions for SIP or transportation conformity purposes, you
should use your own locally-generated MOBELE6.2 emission factors and
local travel activity data to calculate emission reductions.
The guidance "Incorporating Bundled Measures in a State Implementa-
tion Plan (SIP)" released in August 2005 describes an option for how

BWC-related activities could be "bundled" with other voluntary mea-
sures for SIP purposes. In cases where many small employers in an area
are implementing BWC-related activities, it may be appropriate to
consult this guidance along with the Bundled Measures guidance to
quantify and account for the expected emission reductions.
For More information
You can access the guidance, the COMMUTER model, and related
documents on the Office of Transportation and Air Quality (OTAQ) Web
site at: www.epa.gov/otaq/transp/conform/policy.htm

For questions regarding this guidance:
    Mary Walsh

For questions regarding BWC measures in transportation conformity
    Meg Patulski

For questions regarding the COMMUTER model:
    Erik Herzog

For more information about Best Workplaces for CommutersSM, visit the
Web site at www.bwc.gov, send an e-mail message to bwc@epa.gov, or
call the Best Workplaces for CommutersSM information line at 1-888-