Office of Transportation EPA420-B-05-016 

and Air Quality October 2005 

Guidance for Quantifying and 

Using Emission Reductions 

from Best Workplaces for 

Commuter Programs in State 

Implementation Plans and 

Transportation Conformity 

Determinations 
EPA420-B-05-016 

October 2005 

Guidance for Quantifying and Using Emission

Reductions from Best Workplaces for Commuter

Programs in State Implementation Plans and

Transportation Conformity Determinations

Transportation and Regional Programs Division

Office of Transportation and Air Quality

U.S. Environmental Protection Agency
 TABLE OF CONTENTS 

Page 

Section A: Background Information 

1. What is the purpose of this policy?...........................................................................1 

2. What is Best Workplaces for Commuters, and how is it addressed by this

policy?.......................................................................................................................2

3. How BWC and other Commuter Choice Programs Work........................................3 

4. What does it mean that this is a policy and not a regulation?...................................4 

Section B: Basic Criteria Requirements for Using Emissions Reductions from BWCRelated Control Measures 

5. What are the basic requirements for using emission reductions in SIPs or 

transportation conformity?........................................................................................4

6. What must a state submit to EPA to meet the requirements for incorporating a 

source specific control measure in a SIP?.................................................................6 

7. How can the estimated emission reductions be used for SIP purposes?...................6 

8. How can the emission reductions be used for transportation conformity 

purposes?...................................................................................................................7 

9. What quantification methodologies are available to estimate emission reductions of 

BWC-related control measures for SIPs and transportation conformity 

determinations?.........................................................................................................9 

Section C: Penalties 

10. What types of penalties can be assessed for not complying with CAA 

requirements?..........................................................................................................12 

Section D: Contact Information 

11. Who should you contact if you have any questions on this policy?.......................13 

Appendices 

Appendix A: Example Quantification: Best Workplaces for Commuters Employer.......14 

Appendix B: Example Quantification: Best Workplaces for Commuters District.......... 21

Appendix C: Guide to Importing User-Generated MOBILE Emission Factors into the 

COMMUTER Model.........................................................................31 

Appendix D: Best Workplaces for Commuters Program Evaluation Guide...................40

i
Guidance for Quantifying and Using Emission Reductions from Best 

Workplaces for Commuter Programs in State Implementation Plans 

and Transportation Conformity 

Section A: Background Information 

1. What is the purpose of this policy? 

Best Workplaces for CommutersSM (BWC) is a fast-growing partnership program 

between the U.S. Environmental Protection Agency (EPA) and the U.S. Department of 

Transportation (DOT), and private- and public-sector employers throughout the country. 

Through BWC, the numbers of vehicle trips and miles, and hence, emissions of criteria 

pollutants and greenhouse gases are reduced in many communities. This has led to an 

interest on the part of planners in some areas to incorporate these benefits into their state 

implementation plans (SIPs) or transportation conformity determinations. Therefore, EPA 

has prepared this guidance to help states or agencies1

 estimate the emission benefits of 

control measures implemented through BWC and other commuter benefit programs and, 

under appropriate circumstances, take credit for them in SIPs and conformity 

determinations. 

Like other programs offering incentives or encouragement for people to adopt 

more environmentally friendly travel choices, BWC-related measures can be incorporated 

into the SIP as mandatory measures, an Economic Incentive Program (EIP)2, or as a 

voluntary mobile source measure3. For each of these options, a different entity may 

administer and evaluate the commuter benefit program’s measures. For example, a 

voluntary measure program may be entirely administered by individual employers. EPA 

has issued comprehensive guidance documents for each of these types of SIP measures, 

and you should consult the guidance for the type of SIP submittal in which you are 

interested, as this guidance does not reiterate all the requirements for each. 

To aid in quantifying the benefits of BWC-related measures, EPA is releasing an 

updated version of the COMMUTER model, the first version of which was released in 

2000. The new version has the same look and feel and structure as the first; however, it 

1 This document uses “state or agency” to refer to anyone who has authority to submit a SIP or 

conformity determination, such as a local or state government, regional transit authority, local or regional transportation 

planning agency or state or regional air quality agency, that takes action to reduce on-road mobile source emissions 

through a BWC program. 

2

The guidance document for the EIP can be found at: http://www.epa.gov/ttn/ecas/incentiv.html. 

3 For a description of the Mobile Source Voluntary Measures Policy consult the following web site: 

http://www.epa.gov/otaq/transp/traqvolm.htm. 

1
has been updated to incorporate newer travel activity data and MOBILE6.2 emission 

factors, including emission factors for air toxics and particulate matter.4 Other existing 

methodologies may also be appropriate for quantifying the emissions benefits from 

BWC-related measures. See Section B. for more information regarding the basic 

submission and quantification requirements for BWC-related measures in SIPs and 

conformity. 

This guidance supersedes the 1998 document, “State Implementation Plan 

Development Guidance: Using Emission Reductions from Commuter Choice Programs 

to Meet Clean Air Act Requirements” (EPA420-R-98-007). However, the protocols and 

methods described herein can also be used to quantify the benefits of non-BWC Commuter

Choice or other commuter programs. 

2. What is Best Workplaces for CommutersSM, and how is it addressed by this 

policy? 

BWC is a business/government voluntary initiative offering innovative solutions 

to commuting challenges faced by employers and employees. Established by EPA and 

DOT, this program provides the tools, guidance, and promotion necessary to help U.S. 

employers of any size incorporate commuter benefits as part of their standard employee 

benefits plan. Participating companies earn the designation "Best Workplaces for 

CommutersSM," which is a mark of excellence for environmentally and employee-friendly 

organizations. Across the country, more and more communities are earning this 

designation. From urban centers to suburban and even rural settings, each of these areas 

is taking commuter benefits to a new level, providing a valuable advantage to local 

businesses and the people who work there. 

To participate in the BWC program, employers offer their employees a suite of 

commuter benefits that meet EPA’s “National Standard of Excellence.” Employers must 

complete EPA’s online application and agree to several items, including ensuring a 

minimum level of employee participation, designating a central point of contact for 

employee questions, providing an Emergency Ride Home for participating employees, 

and offering a choice of commuter benefits. Best Workplaces for CommutersSM are 

required to offer at least one of the following primary commuter benefit options at each 

qualifying work site: 

• Employer-paid tax-free transit passes 

• Employer-paid tax-free vanpool benefits 

• Telework 

• Parking cash out 

4

 EPA notes that the MOBILE6.2 emissions factors are not applicable to agencies in California, where the 

latest EMFAC emissions model is used. However, the travel activity component on the COMMUTER 

model could be considered by California agencies in consultation with EPA and DOT offices as 

appropriate. 

2
 Sometimes outstanding commuter benefits are provided not by the employers 

themselves, but by another organization such as a business park, downtown district, 

developer, or property manager. To recognize these areas for their leadership, EPA 

designates them a “Best Workplaces for CommutersSM District.” 

As with other voluntary partnership programs, BWC programs and associated 

control measures may be initiated without involving a SIP submittal or conformity 

determination. An employer will implement commuter benefits meeting the BWC 

standard of excellence to meet the needs of its own employees. With this guidance, EPA 

intends to further recognize the air quality benefits of BWC-related control measures in 

conjunction with necessary requirements, but a company can participate as a BWC 

partner regardless of whether its local area will be preparing a SIP submittal or 

transportation conformity determination. 

Individual BWC employer programs are likely to be considered small scale or 

local emissions benefits, and will not normally qualify as regionally significant. See 

Question 9 of this section for further information on quantifying the impacts of BWCrelated measures. 

3. How BWC and other Commuter Choice Programs Work 

Reducing the frequency that commuters drive alone generates air quality benefits. 

The following is a partial list of employee benefits (and potential control measures) 

offered through BWC and other Commuter 

Choice programs: Commuter Choice program means an 

! Free or reduced cost passes for public organized program to encourage employers to 

transportation (such as subway cards, offer flexible commuter benefit options to 

employees. bus tokens, or train tickets), 

! Transit and vanpool vouchers and Best Workplaces for CommutersSM is a 

designation given to employers whose commuter subsidies, choice programs meet EPA’s National Standard 

! Services to facilitate vanpools and of Excellence. (“SM” is the “service mark” that 

carpools (such as providing vans, ride- protects EPA’s rights regarding the designation.) 

matching, and guaranteed ride home Commuter benefit options are any of a number 

services), of flexible commute benefits offered by 

! Park and Ride subsidies, employers. Basic Commuter Choice alternatives 

include transit benefits, vanpool benefits, cash, 

! Telecommuting options (so employees or parking. 

can work at home more often), 

! Proximate Commuting: a program that 

matches employees of multi-site employers (such as banks or chain stores) to the 

branch office nearest their home, 

! Incentives to bike and walk, and 

! Parking Cash Out: employees can trade employer-paid parking space for cash or 

3
other benefits. 

With more options, commuters can be expected to use single-occupant vehicles 

less often. Air quality improves due to the mode shifts that should reduce vehicle miles 

traveled, and thus reduce emissions. 

4. What does it mean that this is a policy and not a regulation? 

The Clean Air Act (CAA) and implementing regulations (including those 

conformity provisions at 40 CFR Parts 51 and 93) contain legally binding requirements. 

This policy document does not substitute for those provisions or regulations, nor is it a 

regulation itself. Thus, it does not impose binding, enforceable requirements on any 

party, and may not be applicable in all situations. The EPA and state decision makers 

retain the discretion to adopt approaches for approval of SIP measures that differ from 

this guidance where appropriate and consistent with applicable law. Any final decisions 

by EPA regarding a particular SIP measure will only be made based on the statute and 

regulations in the context of EPA notice and comment rulemaking on a submitted SIP 

revision. 

Therefore, interested parties may raise questions and objections about the 

substance of this guidance and appropriateness of its application to a particular situation; 

EPA will, and states should, consider whether or not the recommendations in the 

guidance are appropriate in a particular situation. This guidance is a living document and 

may be revised periodically without public notice. However, EPA welcomes public 

comments on this document at any time and will consider those comments in any future 

revision of this guidance document. Finally, this document does not prejudice any future 

final EPA decision regarding approval of any SIP measure. 

Section B: Basic Criteria Requirements for Using Emissions Reductions from BWC 

-related Control Measures 

5. What are the basic requirements for using emission reductions in SIPs? 

In order to be approved as a measure that provides additional emission reductions 

in a SIP, a control measure cannot interfere with other requirements of the CAA, and 

would need to be consistent with SIP reasonable further progress, attainment, or 

maintenance requirements. In addition, the control measure must provide emission 

reductions that meet the requirements described below. 

(A) Quantifiable - The emission reductions from a control measure are 

quantifiable if they can be reliably and replicably measured. Emission reductions 

must be calculated for the time period for which the reductions will be used. See 

4
Question 9 of this section for more information on quantifying emission 

reductions from BWC-related measures. 

(B) Surplus - Emission reductions are generally surplus and can be used as long 

as they are not otherwise relied on to meet other applicable air quality attainment 

and maintenance requirements (i.e., no double-counting of emission reductions). 

In the event that the measure is used to meet such air quality related program 

requirements, they are no longer surplus and may not be used for additional 

credit. 

(C) Federally Enforceable - Depending on how the emission reductions are to be 

used, control measures must be enforceable through a SIP or SIP revision. Where 

the emission reductions are part of a rule or regulation for SIP purposes, they are 

considered federally enforceable if they meet all of the following requirements: 

• They are independently verifiable. 

• Violations are defined, as appropriate. 

• The state or agency and EPA have the ability to enforce the measure if 

violations occur. 

• Those liable for violations can be identified. 

• Citizens have access to all the emissions-related information obtained 

from the responsible party. 

• Citizens can file suits against the responsible party for violations. 

• Violations are practicably enforceable in accordance with EPA guidance 

on practicable enforceability. 

• A complete schedule to implement and enforce the measure has been 

adopted by the implementing agency or agencies. 

If a SIP revision is approved under EPA’s Voluntary Measures Policy, the 

state is responsible for assuring that the reductions credited in the SIP occur. The 

state would need to make an enforceable SIP commitment to monitor, assess and 

report on the emission reductions resulting from the voluntary measure and to 

remedy any shortfalls from forecasted emission reductions in a timely manner. 

Further, the total of all voluntary measures (including BWC-related measures) 

may not exceed 3 percent of the total reductions needed to meet any requirements 

for reasonable further progress, attainment or maintenance. In the circumstance 

where the actual emission reductions achieved are more than the amount 

estimated in the SIP, you may take credit for the additional emission reductions 

provided it does not exceed the 3 percent cap on voluntary measures and meets 

the other requirements of the Voluntary Measures Policy. If you wish to have a 

SIP revision approved under the Voluntary Measures Policy, consult that policy 

for further information. 

5
(D) Permanent - The emission reduction must be permanent throughout the term 

that the credit is granted. 

(E) Adequately Supported – The state must demonstrate that it has adequate 

funding, personnel, and other resources to implement the control measure on 

schedule. 

6. What must a state submit to EPA to meet the requirements for incorporating a 

BWC-related control measure in a SIP? 

The state must submit to EPA a written document that: 

(A) identifies and describes the BWC-related control measure and its 

implementation schedule to reduce emissions within a specific time period; 

(B) contains estimates of emission reductions attributable to the measure, 

including all relevant technical support documentation for your estimates (you 

must rely on the most recent information available at the time the SIP is 

developed, as described in Question 7); 

(C) contains federally enforceable requirements to implement, track, and monitor 

the measure, as applicable; 

(D) enforceably commits to monitor, evaluate, and report the resulting emission 

reductions of the measure, as applicable; 

(E) enforceably commits to remedy any SIP emission shortfall in a timely 

manner if the measure does not achieve estimated emission reductions, as 

applicable; and 

(F) meets all other requirements for SIP revisions under sections 110 and 172 of 

the CAA. 

7. How can the estimated emission reductions be used for SIP purposes? 

For your reasonable further progress, attainment or maintenance SIP, you can use 

the emission reductions that are produced from the BWC-related measure by applying the 

following criteria: 

6
(A) Where required, emission reductions must account for seasonality. For 

example, if your SIP only credits those reductions that take place during the 

summer ozone season, then only reductions that take place during that season may 

be credited. 

(B) An appropriate baseline must be chosen, so that the reductions are only 

assumed for measures that are not already accounted for in the baseline estimates. 

For example, if some employers were offering Commuter Choice measures prior 

to the start of the BWC program, and such measures were already accounted for 

in the baseline estimates of the SIP, the emission reductions associated with 

implementation of those measures (i.e., commuters taking advantage of their 

employee benefits) cannot be included as surplus emission reductions for the SIP. 

(Appendix C provides some guidelines for creating and conducting surveys to 

establish baselines and to assess changes in travel behavior.) 

(C) As required by Clean Air Act section 172(c)(3) and EPA’s regulation at 40 

CFR 51.112(a), states must use the latest planning assumptions available at the 

time that the SIP is developed. In addition, the emissions model approved by 

EPA should be used in quantifying reductions from SIP control measures that are 

under development. Currently, MOBILE6.2 is the latest approved model for use 

in quantifying motor vehicle emissions in most states; EMFAC2002 is the most 

recently approved emissions model for use in California. 

As always, be sure that any reductions taken for BWC-related measures are not 

already considered in the SIP to avoid double-counting of emission reductions. 

8. How can the emission reductions be used for transportation conformity purposes? 

The transportation conformity regulation (40 CFR parts 51 and 93) describes the 

requirements for including emission reductions from on-road mobile control measures in 

a conformity determination for a transportation plan, transportation improvement 

program (TIP), or transportation project. The conformity rule requires a regional 

emissions analysis be conducted for the transportation plan and TIP. In the regional 

emissions analysis, the emissions from the planned transportation system are estimated or 

modeled, just as they are when creating or revising a SIP’s motor vehicle emissions 

inventory (or “motor vehicle emissions budget”). If credit is obtained for a BWC-related 

measure in the SIP’s motor vehicle emissions budget, transportation agencies should 

seriously consider including the credit in the transportation conformity determination. 

To include emission reductions from a BWC-related on-road control measure in a 

regional emissions analysis, the appropriate jurisdictions must be committed to the 

7
measure. The appropriate level of commitment varies according to the requirements 

outlined in 40 CFR 93.122(a), which are described as follows: 

(A) If the measure does not require a regulatory action to be implemented, it can 

be included in an emissions analysis if it is included in the transportation plan and 

TIP with sufficient funding and other resources for its full implementation. 

(B) If the measure requires a regulatory action to be implemented, it can be 

included in an emissions analysis if one of the following has occurred: 

(1) The regulatory action for the measure is already adopted by the 

enforcing jurisdiction (e.g., a state has adopted a rule to require a control 

measure); 

(2) The measure has been included in an approved SIP; or 

(3) There is a written commitment to implement the measure in a 

submitted SIP with a motor vehicle emissions budget that we have found 

adequate. 

(C) If an on-road mobile measure is not included in the transportation plan and 

TIP or the SIP, and it does not require a regulatory action to be implemented, then 

it can be included in the regional emissions analysis if the conformity 

determination contains a written commitment from the appropriate entities to 

implement the measures. Section 93.101 of the conformity rule defines what is 

intended by a “written commitment.” 

Whatever the case, the emission reductions can only be applied in a conformity 

determination for the time period or years in which the BWC-related control measure will 

be implemented. Written commitments must come from the agency with the authority to 

implement the measure. The latest emissions model and planning assumptions that are 

available must be used when calculating emission reductions from the measure, 

according to 40 CFR 93.110 and 93.111. 

Areas should utilize the conformity interagency consultation process to discuss 

the methods and assumptions used to quantify the reductions from the measure. The 

conformity determination should include documentation of the methodology, 

assumptions, and models that were used to calculate emission reductions from BWCrelated measures, as well any commitments that are necessary for implementation, as 

described above. 

9. What quantification methodologies are available to estimate emission reductions 

of BWC-related control measures for SIPs and transportation conformity 

determinations? 

8
If a BWC-related control measure is considered to be regionally significant, then 

the travel impacts of such a measure should be considered in the context of a 

nonattainment or maintenance area’s regional travel demand forecasting.5 (See 40 CFR 

93.122 for applicable procedures for determining regional transportation-related 

emissions.) The interagency consultation (see 40 CFR 93.105 (c)(1)(ii)) should be used 

to determine which projects are considered regionally significant. An example of a 

regionally significant project may be a BWC campaign that is being implemented 

throughout a metropolitan area. The COMMUTER model would not be appropriate to 

use for regionally significant BWC projects developed for SIPs and conformity 

determinations. State, local, and federal air quality and transportation agencies should 

consult on what methods and data are appropriate for quantifying the impacts of such 

BWC-related measures for SIPs and conformity determinations. EPA expects the 

majority of BWC-related control measures to be considered smaller in scale, with the 

emission reductions being quantified using modeling techniques other than regional 

travel models (i.e., “off-model techniques”). 

The following paragraphs describe currently available tools for quantifying the 

travel impacts of non-regionally significant BWC-related measures. To estimate the 

emission reductions due to such BWC-related measures, the recommended approach is to 

estimate the number of commuters who would change their mode of travel (i.e., singleoccupant vehicle (SOV), carpool, vanpool, transit, bicycle, etc.) or trip-making behavior 

(e.g., telecommuters will no longer be making regular worktrips) in response to 

incentives, assistance, or encouragement offered through a BWC program. From this, the 

resultant change in number of trips and miles of travel are calculated, and the change in 

emissions is derived. Forecasting travel behavior impacts is typically the most 

challenging aspect of quantifying a BWC-related measure. BWC can have a wide range 

of effectiveness, based on the details of the particular measures and their implementation 

context. 

Available Tools for Non-regionally Significant Measures 

In 2000, EPA released the COMMUTER model to assist worksite transportation 

coordinators and local planners in estimating the impacts of commuter programs. EPA 

5

Section 93.101 of the transportation conformity rule defines a “regionally significant 

project” as applying to a project that is on a facility that serves regional transportation needs (such 

as access to and from the area outside of the region, major activity centers in the region, major 

planned developments such as new retail malls, sports complexes, etc. or transportation terminals 

as well as most terminals themselves) and would normally be included in the modeling of a 

metropolitan area’s transportation network, including at a minimum all principal arterial 

highways and all fixed guideway transit facilities that offer an alternative to regional highway 

travel. 

9
has updated this model in 2005 to update data within the model as well as expand its use 

for estimating emissions for particulate matter (PM10 and PM2.5) and toxics emissions. 

U.S. EPA’s COMMUTER model is a spreadsheet-based calculator that estimates 

the travel and emissions impacts from BWC and similar workplace-based programs. It 

uses a logit mode-choice model (pivot-point approach) to analyze the effects of several 

strategies simultaneously on mode share, trips, and VMT. The emissions component is 

based on MOBILE6.2 and includes look-up tables of emissions factors for several sets of 

local conditions. The COMMUTER model allows users to input local-specific travel 

data, and emission factors from a MOBILE6.2 run representing the area. Running the 

model requires the user to provide information on the number of employees covered and 

the inducements offered to them. The COMMUTER model and manuals that explain 

how to use it can be downloaded at: http://www.epa.gov/otaq/transp/conform/policy.htm. 

Local travel data needed in the model include starting mode shares and trip 

lengths, average occupancy for carpools and vanpools, the length of the peak period, and 

the percentage of work trips that occur in the peak period. Emissions calculations require 

data on characteristics of the area’s vehicle fleet, and on fuel control and I/M programs if 

in place for a given nonattainment or maintenance area. 

The updated 2005 COMMUTER model provides MOBILE6.2 look-up tables with 

emission estimates in pounds per day for HC, CO, NOx, PM2.5, CO2, and the following 

air toxics: acetaldehyde, acrolein, benzene, 1,3-butadiene, formaldehyde, and MTBE. It 

also provides estimates in tons per day for HC, CO, and NOx, and in metric tons per day 

for CO2. A user wanting emissions of PM10 rather than PM2.5 can import a MOBILE6.2 

run with emission factors for PM10. The MOBILE6.2 look-up tables in the 2005 

COMMUTER model can be employed for using the model as a screening tool. However, 

if you want to use the COMMUTER model to produce emissions reductions for SIP or 

conformity purposes, you would use your own locally-generated MOBILE6.2 emission 

factors to calculate emissions reductions in the COMMUTER model. As stated 

previously, the COMMUTER model cannot be used for regionally significant projects. 

The following list includes other examples of off-model methodologies that EPA 

may accept for SIPs and conformity purposes, in combination with the latest emissions 

factor model: 

• TDM Evaluation Model 

• TCM Analyst (also referred to as “EPA TCM Methodology”) 

• CM/AQ Evaluation Model 

• Center for Urban Transportation Research Average Ridership Model 

• TCM Tools 

• Off-Net/PAQONE 

10
• ECO/Regulation XV Software 

• California Standardized Cost-Effectiveness Methodology 

• Regional Air Quality Council (RAQC) Workbook 

• Metropolitan Washington Council of Governments Sketch-Planning Methods 

• ITS Deployment Analysis System (IDAS) 

• Simplified Methods for Analysis of Regional Travel (SMART) 

This is not an exhaustive list, and the inputs and outputs of the methodologies vary. The 

choice of model(s) will depend upon the requirements of each situation and the available 

data. 

Considerations for Data for Quantification of All BWC-related Measures 

When quantifying the impacts of BWC-related measures, a state or agency should 

carefully consider the underlying data utilized to estimate travel behavior, especially if 

using off-model and sketch planning techniques. The interagency consultation process 

should be used when deciding the appropriate inputs for quantification. The following 

items should be considered when quantifying the travel impacts of any BWC-related 

control measure. 

(A) Reasonable assumptions for employee participation. A state or agency 

should assume a reasonable level of participation from eligible employees, since not 

every eligible employee may be expected to take advantage of BWC-related measures. 

Survey methods can be used to capture the level of employee participation, both before 

and after a measure has been implemented. For example, a survey of employees at an 

employment site may be performed to determine how many people expect to use or have 

actually used employer-subsidized transit passes. Pre- and post-implementation surveys 

of actual travel behavior are often both feasible and necessary if the effectiveness of 

BWC is to be evaluated retrospectively. 

(B) Experience from other areas. In some cases, a state or agency may be 

able to use input information from other nonattainment or maintenance areas that is 

applicable, when an area does not have such local information. For example, a study may 

have found in another area that five percent of office workers will telecommute one day a 

week if provided the opportunity. It is important to consider whether inputs or other 

information from another area is applicable for your area. 

(C) Elasticities. Finally, a state or agency should use the most appropriate 

elasticity assumptions for travel decisions when quantifying BWC-related measures. An 

elasticity says that an X percent change of an input variable (e.g., the cost of parking) 

11
produces a Y percent change of an output variable (e.g., drive-alone mode share). 

Elasticities may be developed from direct observation or from coefficients of a model 

such as a mode choice model. While they can account for different levels of the input 

variable, they are not necessarily valid outside the range for which they were developed. 

For example, an increase in the cost of parking from $0.00 to $1.00 is an infinite 

percentage change, producing meaningless results. Also, elasticities developed in one 

setting cannot necessarily be assumed accurate in another setting. 

Another important consideration is interaction among strategies. Some strategies 

may complement each other (e.g., parking management and ridesharing incentives), 

leading to cumulative effects greater than the sum of the effects of the strategies if 

applied individually. Conversely, in some cases the effects of multiple programs may be 

smaller than the sum of their individual effects. For example, some BWC measures may 

compete for the same market of travelers, thus leading to diminishing returns as more 

measures are implemented. 

Section C: Penalties 

10. What types of penalties can be assessed for not complying with CAA 

requirements? 

Use of this guidance does not relieve you of any obligation to comply with all 

otherwise applicable CAA requirements, including those pertaining to the crediting of 

emission reductions for your SIP, such as for your attainment demonstration or 

maintenance plan. Violations of CAA requirements are subject to administrative, civil, 

and/or criminal enforcement under Section 113 of the CAA, as well as to citizen suits 

under Section 304 of the CAA. The full range of penalty and injunctive relief options 

would be available to the federal or state government (or citizens) bringing the 

enforcement action. 

Any person who submits false information to you or fails to implement or comply 

with provisions pursuant to this guidance necessary to demonstrate compliance with 

CAA requirements, should be subject to one or more of the following actions, as 

appropriate: 

(A) Disapprove the application for emission reductions. 

(B) Void all previously issued emission reductions. 

(C) Designate the responsible party to be ineligible to generate emission 

reductions. 

(D) Assess a penalty (see paragraph above). 

Section D: Contact Information 

12
11. Whom should you contact if you have any questions on this policy? 

If you are interested in developing programs that may qualify for inclusion in SIP 

and transportation conformity determinations, contact the EPA Regional Office with 

responsibility for air quality planning in the area in which the BWC or BWC district is 

located. A contact list of your EPA Regional Office is available at the following web 

address: 

http://www.epa.gov/otaq/transp/conform/contacts.htm. 

For general questions regarding this Best Workplaces for Commuters and the 

policy, contact Mary Walsh at 734-214-4205 (walsh.mary@epa.gov) or Erik Herzog at 

734-214-4487 (herzog.erik@epa.gov). 

For questions regarding the COMMUTER model, contact Erik Herzog at (734) 

214-4487 (herzog.erik@epa.gov). 

For questions regarding using BWC-related control measures in transportation 

conformity determinations, contact Meg Patulski at 734-214-4842 

(patulski.meg@epa.gov). 

For more information on Best Workplaces for Commuters, visit 

http://www.bwc.gov, or email bwc@epa.gov. 

13
Appendix A: 

Example Quantification: Best Workplaces for Commuters Employer 

The simplest way to model commuter benefits programs with the COMMUTER model is 

at the single worksite level. In this example we model the commuter benefits package 

offered by the University of Michigan in Ann Arbor. In this example, the default 

MOBILE6 emission factor look-up tables are used; area-specific MOBILE emission 

factors have not been imported into the model. Hence, this exercise simulates the 

preliminary sketch planning a local planner would do to determine whether or not to 

include the emission reductions from this worksite’s program into the area’s SIP or TIP. 

Instructions on how to import area-specific MOBILE6.2 emission factors into 

COMMUTER can be found in Appendix E. The University began offering free transit 

passes to employees who agreed to forego the purchase of an annual parking permit in 

1997. Approximately 3,000 employees took this benefit annually. The University began 

a vanpool program in 2001, and then outsourced it in 2003 to a firm that was able to 

upgrade the program in a number of ways. The University implemented a variety of 

other support programs during this time-span and was recognized as a BWC in 2003. 

The University offers a vanpool subsidy of up to $55 per month, guaranteed ride home, 

shuttle to transit stations, bicycle facilities, and preferential parking for carpools and 

vanpools. It also negotiated free transit passes for all students, faculty, and staff. In this 

scenario we model only the benefits put in place in 2003, when the University was 

designated as a BWC. For this reason the transit pass in lieu of parking and the 

preferential parking elements are not modeled. 

Step 1: Scenario Information 

- Metropolitan Area Size: 3 (Small) 

- Analysis Scope: 2 (Site Specific) 

- Analysis Area Type: 1 (CBD – Central Business District) 

- Employment in the Analysis Area: 27,500 (all assigned to office) 

- Programs: 1 (Site Walk Access Improvements) 3 (Financial Incentives) and 4 

(Employer Support Programs) 

Step 2: Local Data 

Mode choice data from the 2000 Census are available from the Southeast Michigan 

Council of Governments (SEMCOG) for both the City of Ann Arbor, and Washtenaw 

County, in which Ann Arbor is located. 

14
Mode City of Ann Arbor Washtenaw County 

Auto - Drive Alone 63.0% 76.0% 

Auto - Carpool 7.5% 8.5% 

Vanpool 0.5% 0.5% 

Transit 7.0% 3.0% 

Bicycle 0.0% 0.0% 

Walk 16.0% 7.0% 

Other 6.0% 5.0% 

Because much of Washtenaw County outside of Ann Arbor is rural, the drive-alone share 

is considerably higher, and the transit share considerably lower than for the City. It 

would be best in this instance to use starting mode shares that are specific to the U of M 

work force. Lacking that we will use the County mode shares because the model 

produces more conservative results; i.e., smaller mode shifts, when these mode shares are 

used. The reason for this is that when the time or cost of using a mode is reduced, the 

shift toward that mode predicted by COMMUTER is proportional to the size of that 

mode’s starting share. In other words, a transit subsidy of a given size -- $1.88 per day in 

this example – will produce a larger shift toward transit if the transit mode share is 7 

percent initially than if it is 3 percent. 

Step 3: Edit Coefficients 

Mode choice coefficients for the Detroit area are selected as these are also applicable to 

the Ann Arbor area. 

15
Step 4: TCM Specific Data Screens – Site Access and Transit Service Improvements 

The shuttles to transit stations are estimated to reduce transit riders’ walk time by five 

minutes. 

16
Step 5: TCM Specific Data – Financial Incentives and Parking Costs 

A vanpool subsidy of $55 per month works out to $2.75 per day. The employer 

participation rate is moot, since we are only modeling a single worksite. A monthly 

transit pass on the Ann Arbor Transit Authority system (AATA) costs $37.50, which 

works out to $1.88 per day. Three thousand staff persons (11 percent) received transit 

passes under the previous system where they received a transit pass in lieu of a parking 

space, so the effective subsidy is reduced by 11 percent in order to estimate the effect of 

the increment in the benefit. This makes the effective daily subsidy $1.67. 

17
Step 5: TCM Specific Data – 

The various support programs that the University offers for carpooling, vanpooling, 

transit, and bicycling, in conjunction with the guaranteed ride home element, are modeled 

as Level 4 support. However, these programs were in place before the University was 

designated as a BWC, so both the existing and the new levels of support for these 

programs are entered as 4. 

18
Step 6: Emissions-Related Input Screens 

Six inputs are required for this module: 

- Calendar Year of Analysis 

- Season 

- Climate Type 

- I/M Program Type 

- Fuel Type 

- PADD 

19
Step 7: Other Emissions-Related Data 

All defaults are used for this module. 

Results: 

Below is the output from this COMMUTER run, using all the variable values described 

in these steps: 

20
21
Appendix B: 

Example Quantification: Best Workplaces for Commuters District 

A Best Workplaces for Commuters (BWC) District is a geographically defined area in 

which all employees are offered commuter benefits that meet the BWC National Standard 

of Excellence. As of May 2005, there are 16 BWC Districts in seven states. Among these 

16 are downtown Business Improvement Districts (BIDs), suburban office parks, 

shopping centers, and a collection of rural neighborhoods on the Vermont/New 

Hampshire border. 

BWC Districts meet the National Standard of Excellence for commuter benefits through a 

variety of means. Some offer free bus passes to all employees within the district (e.g., 

Cities of Boulder and Aspen, Colorado). Others subsidize vanpool riders (e.g., 

Cumberland and Buckhead in Atlanta), or set up free shuttle services to connect local 

transit stations with worksites (e.g., Emeryville, California, and the South Florida 

Education Center in Davie, Florida). In addition to these primary benefits, all these 

districts provide supporting commuter benefits, such as centralized carpool matching, 

bicycle racks and shower facilities, and employee commuting awards programs. 

Following is an example of how a user would incorporate data obtained from a District 

area into the COMMUTER model (described in Section C) in order to learn what mode 

share and travel impacts, and emission reductions, would result from BWC-related 

control measures. In this example, the default MOBILE6 emission factor look-up tables 

are used; area-specific MOBILE emission factors have not been imported into the model. 

Hence, this exercise simulates the preliminary sketch planning a local planner would do 

to determine whether or not to include the emission reductions from this worksite’s 

program into the area’s SIP or TIP. Instructions on how to import area-specific 

MOBILE6.2 emission factors into COMMUTER can be found in Appendix E. 

Step 1: Scenario Information 

The following basic scenario information is needed to operate COMMUTER: 

- Metropolitan Area Size 

- Analysis Scope 

- Analysis Area Type 

- Employment in the Analysis Area 

- Programs 

For this example, a hypothetical Best Workplaces for Commuters District called “Nosolo 

Drive Business Park” in suburban San Francisco, California, the following inputs are 

used: 

- Metropolitan Area Size: 1 (Large) 

- Analysis Scope: 1 (Area Wide) 

- Analysis Area Type: 2 (Other High –Density Commercial) 

- Employment in the Analysis Area: 30,000 (25,000 office and 5,000 other) 

22
- Programs: 3 (Financial Incentives) and 4 (Employer Support Programs) 

Step 2: Local Data 

This portion of COMMUTER requires the following inputs: 

- Work Trip Mode Shares 

- Work Trip Length 

- Vehicle Occupancy 

- Length of Peak Period (hours) 

- Percent of Work Trips in Peak Periods 

For all of these, the model default values are used since this is a hypothetical district 

Step 3: Edit Coefficients 

The Edit Coefficients for the San Francisco City Specific defaults are used 

Step 4: TCM Specific Data – Financial Incentives 

23
For this example, the Nosolo Drive transit subsidy program is modeled. This program 

subsidizes the cost of a monthly transit pass by $60, or $3.00 per day (based on 20 work 

days per month) to all participating employees. Therefore, in the ‘Change in Daily Cost’ 

box in the financial incentives input screen, the input value is –3.00 (negative since the 

cost to the rider is decreased). The employer participation rate is set at 30%, a value that 

represents the assumed percent of employees within the District that have received 

information about commuting alternatives from their employers. This measure represents 

a better reflection of the percent of employees that may consider taking advantage of the 

transit subsidy (and other commuter benefits described in Step 5 below.) 

This information is shown in the following screenshot: 

Step 5: TCM Specific Data Screens – Site-Specific Employer Support Programs 

In the baseline case in the Nosolo Drive Business Park, additional TCM services are 

provided to a degree equivalent to the ‘1’ level for all four program components (carpool, 

vanpool, transit, and bicycle). 

24
The transit subsidy program that forms the basis for this TCM measure is accompanied 

by an improvement in the Site-Specific (or, in this case, District-Specific) increase in the 

level of support for all four of these program components, bringing them up to a ‘4’ level. 

On the Area-Wide Employer Support Programs Input Screen, the baseline (existing) 

program levels are set at 30% for all four components at the ‘1’ level. Under the new, 

TCM program, the program levels are set at 30% for all components at the ‘4’ level. 

The reason for using 30%, rather than 100%, is that, as described in Step 4, it is assumed 

that employees in the District have a 30% level of awareness of the alternate commuter 

programs available in the district. 

Step 6: Emissions-Related Input Screens 

Six inputs are required for this module: 

- Calendar Year of Analysis 

- Season 

- Climate Type 

- I/M Program Type 

- Fuel Type 

25
- PADD 

For the first three inputs, 2007 (the earliest available), summer, and moderate are entered. 

(Moderate because the average temperatures in the summer in San Francisco are between 

65 and 85 Fahrenheit). 

For I/M (Inspection/Maintenance) type, the city of San Francisco requires an inspection 

equivalent to the ‘Enhanced I/M’ level. 

Fuel type in San Francisco is ‘C’, Conventional. 

PADD (Petroleum Administration for Defense District) is ‘5’ for the entire West coast. 

26
Step 7: Other Emissions-Related Data 

All defaults are used for this module. 

Results:

Below is the output from this COMMUTER run, using all the variable values described 

in these steps. 

27
28
Step 8: Projected effects of an awareness campaign 

As a final step, a new hypothetical scenario was developed. In this scenario, all model 

inputs were maintained as constant except for the employer participation rates (used in 

steps 4 and 5, and set at 30%.) In this case the managers of the District’s commuter 

benefits program launch a marketing campaign that results in the increase employer 

participation from 30% to 50%. When these percentages are changed in the appropriate 

places, the following results are generated: 

29
30
Appendix C: 

Guide to Importing User-Generated MOBILE Emission Factors 

into the COMMUTER Model 

COMMUTER has been supplied with 192 sets of MOBILE6.2 emission factors that 

encompass a range of input conditions throughout the country. Each of these supplied 

data sets contains emission factors for six calendar years: 2007, 2009, 2010, 2013, 2019, 

and 2021. Under general circumstances when COMMUTER is used as a screening 

model, selecting the set of pre-loaded emission factors that best matches your local 

conditions is adequate. However, if you want to use COMMUTER to produce emission 

reductions reflecting local conditions, such as for SIP or conformity purposes, you must 

use your own locally generated MOBILE6.2 emission factors to calculate emission 

reductions in COMMUTER. The steps for using your own emission factors are 

explained below. 

Step 1 - Create Properly Formatted Emission Factor Output File - Although you 

can specify your exact local input conditions, your MOBILE6.2 output emission 

factors must be generated in a specific format expected by COMMUTER. The 

sample MOBILE6.2 template input file M6SAMPLE.IN, which is provided with 

the model, identifies how specific commands in the MOBILE6.2 input file must 

be set to produce output emission factors in the COMMUTER-required format. 

In addition, it contains a series of 13 "Scenario" records that produce emission 

factors over a range of speeds expected by COMMUTER. These scenario 

records can be edited to reflect the altitude, calendar year, local ambient 

temperature, season of interest, and local fuels data. In addition, the user may 

specify other locality-specific data in the "Run Data" or "Scenario" sections, such 

as I/M programs, vehicle registration distributions, or alternative Tier 2 phase-in 

schedules. Speed data files for each scenario are provided with the model and 

should not be edited. 

In addition, the user must specify the "database output" option with the formats 

shown in the sample file. In addition, the user must specify calculation of 

particulate matter as well as air toxics, as shown in the sample file, and provide 

the fuel parameters and particulate matter emission factor inputs in each scenario 

record, as required by MOBILE6.2 to calculate particulate matter and air toxics 

emissions. If these conventions are not followed, the resulting MOBILE6.2 

model output will not work properly with COMMUTER. 

31
IMPORTANT: Once you’ve edited the 13 scenario records to 

reflect your own altitude, temperature, and season inputs, you can 

copy and paste this block of records to create emission factors for 

multiple calendar years. 

Once you have set up your MOBILE6.2 input file as described above and in 

accordance with the required database output options, run MOBILE6.2. You can 

name the MOBILE6.2 input and output files as you choose. 

Step 2 - Process MOBILE6.2 Output - Once you have run MOBILE6.2, an 

intermediate step is required to process MOBILE6.2 database-format output into 

the format expected by COMMUTER. You can run this step from inside the 

COMMUTER model using the "Process MOBILE6.2 Output" command from the 

"File" menu. This command will allow you to browse for and select a standard 

MOBILE6.2 database output file (.TB1) extension. It will then convert the data in 

this file into a text file suitable for import into COMMUTER, with a .TBZ 

extension. Note that corresponding toxics and PM MOBILE6.2 output files are 

also read (.TOX and .PM extensions, respectively), and a corresponding VMT file 

(.VMT) is also generated that contains VMT fractions by vehicle type and facility 

type. The model user must retain these files in the same directory as the .TB1 and 

.TBZ files and should not delete them. The routine to process MOBILE output 

may take a few minutes to run; this is normal. 

Step 3 - Activate User-Supplied Emission Factors Option - On the "Fleet 

Emissions Information" input screen in COMMUTER, you have the option of 

selecting "User-Supplied Emission Factors." Once you have selected this option 

and specified a calendar year, you will be reminded to Import User Emission 

Factors, as described below. It is important that the calendar year you have 

specified match one of the calendar years included in the .TBZ file you select. 

Step 4 - Import User Emission Factors - Once you have generated a .TBZ file, 

you can import this file into the COMMUTER model using the "Import User 

Emission Factors" command from the "File" menu. This command will allow 

you to browse for and select a .TBZ file. You may select any .TBZ file that you 

already have generated from MOBILE6.2 output, without re-running the "process 

MOBILE6.2 output" routine described above. Importing the .TBZ file will take a 

few seconds; you will be notified when the import routine has been successfully 

completed. These emission factors will be saved within the COMMUTER model 

until you import a different set of either user-specified or default scenario 

emission factors. 

Sample MOBILE6.2 Input File 

32
MOBILE6 INPUT FILE : M6sample.in 

*This is a sample MOBILE6.2 input file, provided for use with EPA's COMMUTER Model v2.0. 

*Requirements: 

**** The DATABASE OUTPUT option must be used with the format options as shown. 

  The PARTICULATES and AIR TOXICS commands must be used as shown.

** ** 13 scenarios must be run, one for each speed range, using the external speed files provided. 

  The user must provide locality-specific fuel parameters in each SCENARIO record, 

** ** suitable for use with the PARTICULATES and AIR TOXICS commands. 

*User options: 

**** The user may alter the calendar year, season, altitude, and temperature in the scenario 

  records, and may provide additional local data in the scenario record (e.g., humidity). 

** ** The user may specify other locality-specific data either internally or in external files 

**** (e.g., I/M program, alternative Tier 2 phase-in, vehicle registration distribution). 

DATABASE OUTPUT : 

POLLUTANTS : HC CO NOX CO2 

WITH FIELDNAMES : 

DATABASE VEHICLES : 22222 11111111 2 222 11111111 221 

DAILY OUTPUT : 

PARTICULATES : SO4 GASPM LEAD SO2 NH3 BRAKE TIRE 

AIR TOXICS : 

* ------------------------------ 

RUN DATA : 

EXPRESS HC AS VOC : 

FUEL PROGRAM : 4 

30 30 30 30 30 30 30 30 

30 30 30 30 30 30 30 30 

80 80 80 80 80 80 80 80 

80 80 80 80 80 80 80 80 

I/M DESC FILE : basic.im 

SCENARIO RECORD : Weekday 2007 Speed01.svt 

> NOTE Scenario speed: Speed01.svt 

CALENDAR YEAR : 2007 

SEASON : 1 

FUEL RVP : 8.38 

MIN/MAX TEMPERATURE: 55.0 75.0 

ALTITUDE : 1 

PARTICULATE EF : PMGZML.CSV PMGDR1.CSV PMGDR2.CSV PMDZML.CSV 

PMDDR1.CSV PMDDR2.CSV 

PARTICLE SIZE : 2.5 

DIESEL SULFUR : 87.75 

SPEED VMT : Speed01.svt 

GAS AROMATIC% : 26.87 

GAS OLEFIN% : 13.23

GAS BENZENE% : 01.00 

E200 : 47.72 

E300 : 82.84 

OXYGENATE : MTBE 02.6200 1.00 

33
 : ETBE 00.0000 0.00 

 : ETOH 00.0000 0.00 

 : TAME 00.0000 0.00 

* ------------------------------ 

SCENARIO RECORD : Weekday 2007 Speed02.svt 

> NOTE Scenario speed: Speed02.svt 

CALENDAR YEAR : 2007 

SEASON : 1 

FUEL RVP : 8.38 

MIN/MAX TEMPERATURE: 55.0 75.0 

ALTITUDE : 1 

PARTICULATE EF : PMGZML.CSV PMGDR1.CSV PMGDR2.CSV PMDZML.CSV 

PMDDR1.CSV PMDDR2.CSV 

PARTICLE SIZE : 2.5 

DIESEL SULFUR : 87.75 

SPEED VMT : Speed02.svt 

GAS AROMATIC% : 26.87 

GAS OLEFIN% : 13.23 

GAS BENZENE% : 01.00 

E200 : 47.72 

E300 : 82.84 

OXYGENATE : MTBE 02.6200 1.00 

 : ETBE 00.0000 0.00 

 : ETOH 00.0000 0.00 

 : TAME 00.0000 0.00 

* ------------------------------ 

SCENARIO RECORD : Weekday 2007 Speed03.svt 

> NOTE Scenario speed: Speed03.svt 

CALENDAR YEAR : 2007 

SEASON : 1 

FUEL RVP : 8.38 

MIN/MAX TEMPERATURE: 55.0 75.0 

ALTITUDE : 1 

PARTICULATE EF : PMGZML.CSV PMGDR1.CSV PMGDR2.CSV PMDZML.CSV 

PMDDR1.CSV PMDDR2.CSV 

PARTICLE SIZE : 2.5 

DIESEL SULFUR : 87.75 

SPEED VMT : Speed03.svt 

GAS AROMATIC% : 26.87 

GAS OLEFIN% : 13.23 

GAS BENZENE% : 01.00 

E200 : 47.72 

E300 : 82.84 

OXYGENATE : MTBE 02.6200 1.00 

 : ETBE 00.0000 0.00 

 : ETOH 00.0000 0.00 

 : TAME 00.0000 0.00 

* ------------------------------ 

SCENARIO RECORD : Weekday 2007 Speed04.svt 

34
> NOTE Scenario speed: Speed04.svt 

CALENDAR YEAR : 2007 

SEASON : 1 

FUEL RVP : 8.38 

MIN/MAX TEMPERATURE: 55.0 75.0 

ALTITUDE : 1 

PARTICULATE EF : PMGZML.CSV PMGDR1.CSV PMGDR2.CSV PMDZML.CSV 

PMDDR1.CSV PMDDR2.CSV 

PARTICLE SIZE : 2.5 

DIESEL SULFUR : 87.75 

SPEED VMT : Speed04.svt 

GAS AROMATIC% : 26.87 

GAS OLEFIN% : 13.23 

GAS BENZENE% : 01.00 

E200 : 47.72 

E300 : 82.84 

OXYGENATE : MTBE 02.6200 1.00 

 : ETBE 00.0000 0.00 

 : ETOH 00.0000 0.00 

 : TAME 00.0000 0.00 

* ------------------------------ 

SCENARIO RECORD : Weekday 2007 Speed05.svt 

> NOTE Scenario speed: Speed05.svt 

CALENDAR YEAR : 2007 

SEASON : 1 

FUEL RVP : 8.38 

MIN/MAX TEMPERATURE: 55.0 75.0 

ALTITUDE : 1 

PARTICULATE EF : PMGZML.CSV PMGDR1.CSV PMGDR2.CSV PMDZML.CSV 

PMDDR1.CSV PMDDR2.CSV 

PARTICLE SIZE : 2.5 

DIESEL SULFUR : 87.75 

SPEED VMT : Speed05.svt 

GAS AROMATIC% : 26.87 

GAS OLEFIN% : 13.23 

GAS BENZENE% : 01.00 

E200 : 47.72 

E300 : 82.84 

OXYGENATE : MTBE 02.6200 1.00 

 : ETBE 00.0000 0.00 

 : ETOH 00.0000 0.00 

 : TAME 00.0000 0.00 

* ------------------------------ 

SCENARIO RECORD : Weekday 2007 Speed06.svt 

> NOTE Scenario speed: Speed06.svt 

CALENDAR YEAR : 2007 

SEASON : 1 

FUEL RVP : 8.38 

MIN/MAX TEMPERATURE: 55.0 75.0 

35
ALTITUDE : 1 

PARTICULATE EF : PMGZML.CSV PMGDR1.CSV PMGDR2.CSV PMDZML.CSV 

PMDDR1.CSV PMDDR2.CSV 

PARTICLE SIZE : 2.5 

DIESEL SULFUR : 87.75 

SPEED VMT : Speed06.svt 

GAS AROMATIC% : 26.87 

GAS OLEFIN% : 13.23 

GAS BENZENE% : 01.00 

E200 : 47.72 

E300 : 82.84 

OXYGENATE : MTBE 02.6200 1.00 

 : ETBE 00.0000 0.00 

 : ETOH 00.0000 0.00 

 : TAME 00.0000 0.00 

* ------------------------------ 

SCENARIO RECORD : Weekday 2007 Speed07.svt 

> NOTE Scenario speed: Speed07.svt 

CALENDAR YEAR : 2007 

SEASON : 1 

FUEL RVP : 8.38 

MIN/MAX TEMPERATURE: 55.0 75.0 

ALTITUDE : 1 

PARTICULATE EF : PMGZML.CSV PMGDR1.CSV PMGDR2.CSV PMDZML.CSV 

PMDDR1.CSV PMDDR2.CSV 

PARTICLE SIZE : 2.5 

DIESEL SULFUR : 87.75 

SPEED VMT : Speed07.svt 

GAS AROMATIC% : 26.87 

GAS OLEFIN% : 13.23 

GAS BENZENE% : 01.00 

E200 : 47.72 

E300 : 82.84 

OXYGENATE : MTBE 02.6200 1.00 

 : ETBE 00.0000 0.00 

 : ETOH 00.0000 0.00 

 : TAME 00.0000 0.00 

* ------------------------------ 

SCENARIO RECORD : Weekday 2007 Speed08.svt 

> NOTE Scenario speed: Speed08.svt 

CALENDAR YEAR : 2007 

SEASON : 1 

FUEL RVP : 8.38 

MIN/MAX TEMPERATURE: 55.0 75.0 

ALTITUDE : 1 

PARTICULATE EF : PMGZML.CSV PMGDR1.CSV PMGDR2.CSV PMDZML.CSV 

PMDDR1.CSV PMDDR2.CSV 

PARTICLE SIZE : 2.5 

DIESEL SULFUR : 87.75 

SPEED VMT : Speed08.svt 

36
GAS AROMATIC% : 26.87 

GAS OLEFIN% : 13.23 

GAS BENZENE% : 01.00 

E200 : 47.72 

E300 : 82.84 

OXYGENATE : MTBE 02.6200 1.00 

 : ETBE 00.0000 0.00 

 : ETOH 00.0000 0.00 

 : TAME 00.0000 0.00 

* ------------------------------ 

SCENARIO RECORD : Weekday 2007 Speed09.svt 

> NOTE Scenario speed: Speed09.svt 

CALENDAR YEAR : 2007 

SEASON : 1 

FUEL RVP : 8.38 

MIN/MAX TEMPERATURE: 55.0 75.0 

ALTITUDE : 1 

PARTICULATE EF : PMGZML.CSV PMGDR1.CSV PMGDR2.CSV PMDZML.CSV 

PMDDR1.CSV PMDDR2.CSV 

PARTICLE SIZE : 2.5 

DIESEL SULFUR : 87.75 

SPEED VMT : Speed09.svt 

GAS AROMATIC% : 26.87 

GAS OLEFIN% : 13.23 

GAS BENZENE% : 01.00 

E200 : 47.72 

E300 : 82.84 

OXYGENATE : MTBE 02.6200 1.00 

 : ETBE 00.0000 0.00 

 : ETOH 00.0000 0.00 

 : TAME 00.0000 0.00 

* ------------------------------ 

SCENARIO RECORD : Weekday 2007 Speed10.svt 

> NOTE Scenario speed: Speed10.svt 

CALENDAR YEAR : 2007 

SEASON : 1 

FUEL RVP : 8.38 

MIN/MAX TEMPERATURE: 55.0 75.0 

ALTITUDE : 1 

PARTICULATE EF : PMGZML.CSV PMGDR1.CSV PMGDR2.CSV PMDZML.CSV 

PMDDR1.CSV PMDDR2.CSV 

PARTICLE SIZE : 2.5 

DIESEL SULFUR : 87.75 

SPEED VMT : Speed10.svt 

GAS AROMATIC% : 26.87 

GAS OLEFIN% : 13.23 

GAS BENZENE% : 01.00 

E200 : 47.72 

E300 : 82.84 

37
OXYGENATE : MTBE 02.6200 1.00 

 : ETBE 00.0000 0.00 

 : ETOH 00.0000 0.00 

 : TAME 00.0000 0.00 

* ------------------------------ 

SCENARIO RECORD : Weekday 2007 Speed11.svt 

> NOTE Scenario speed: Speed11.svt 

CALENDAR YEAR : 2007 

SEASON : 1 

FUEL RVP : 8.38 

MIN/MAX TEMPERATURE: 55.0 75.0 

ALTITUDE : 1 

PARTICULATE EF : PMGZML.CSV PMGDR1.CSV PMGDR2.CSV PMDZML.CSV 

PMDDR1.CSV PMDDR2.CSV 

PARTICLE SIZE : 2.5 

DIESEL SULFUR : 87.75 

SPEED VMT : Speed11.svt 

GAS AROMATIC% : 26.87 

GAS OLEFIN% : 13.23 

GAS BENZENE% : 01.00 

E200 : 47.72 

E300 : 82.84 

OXYGENATE : MTBE 02.6200 1.00 

 : ETBE 00.0000 0.00 

 : ETOH 00.0000 0.00 

 : TAME 00.0000 0.00 

* ------------------------------ 

SCENARIO RECORD : Weekday 2007 Speed12.svt 

> NOTE Scenario speed: Speed12.svt 

CALENDAR YEAR : 2007 

SEASON : 1 

FUEL RVP : 8.38 

MIN/MAX TEMPERATURE: 55.0 75.0 

ALTITUDE : 1 

PARTICULATE EF : PMGZML.CSV PMGDR1.CSV PMGDR2.CSV PMDZML.CSV 

PMDDR1.CSV PMDDR2.CSV 

PARTICLE SIZE : 2.5 

DIESEL SULFUR : 87.75 

SPEED VMT : Speed12.svt 

GAS AROMATIC% : 26.87 

GAS OLEFIN% : 13.23 

GAS BENZENE% : 01.00 

E200 : 47.72 

E300 : 82.84 

OXYGENATE : MTBE 02.6200 1.00 

 : ETBE 00.0000 0.00 

 : ETOH 00.0000 0.00 

 : TAME 00.0000 0.00 

* ------------------------------ 

38
SCENARIO RECORD : Weekday 2007 Speed13.svt 

> NOTE Scenario speed: Speed13.svt 

CALENDAR YEAR : 2007 

SEASON : 1 

FUEL RVP : 8.38 

MIN/MAX TEMPERATURE: 55.0 75.0 

ALTITUDE : 1 

PARTICULATE EF : PMGZML.CSV PMGDR1.CSV PMGDR2.CSV PMDZML.CSV 

PMDDR1.CSV PMDDR2.CSV 

PARTICLE SIZE : 2.5 

DIESEL SULFUR : 87.75 

SPEED VMT : Speed13.svt 

GAS AROMATIC% : 26.87 

GAS OLEFIN% : 13.23 

GAS BENZENE% : 01.00 

E200 : 47.72 

E300 : 82.84 

OXYGENATE : MTBE 02.6200 1.00 

 : ETBE 00.0000 0.00 

 : ETOH 00.0000 0.00 

 : TAME 00.0000 0.00 

* ------------------------------ 

SCENARIO RECORD : Weekday 2007 Speed14.svt 

> NOTE Scenario speed: Speed14.svt 

CALENDAR YEAR : 2007 

SEASON : 1 

FUEL RVP : 8.38 

MIN/MAX TEMPERATURE: 55.0 75.0 

ALTITUDE : 1 

PARTICULATE EF : PMGZML.CSV PMGDR1.CSV PMGDR2.CSV PMDZML.CSV 

PMDDR1.CSV PMDDR2.CSV 

PARTICLE SIZE : 2.5 

DIESEL SULFUR : 87.75 

SPEED VMT : Speed14.svt 

GAS AROMATIC% : 26.87 

GAS OLEFIN% : 13.23 

GAS BENZENE% : 01.00 

E200 : 47.72 

E300 : 82.84 

OXYGENATE : MTBE 02.6200 1.00 

 : ETBE 00.0000 0.00 

 : ETOH 00.0000 0.00 

 : TAME 00.0000 0.00 

END OF RUN : 

39
Appendix D: 

Best Workplaces for Commuters Program Evaluation Guide 

Surveying Employees 

Q: What questions should I ask employees in the survey? 

A: To make program evaluation simpler for you, we have provided a sample Employee 

Survey to illustrate the minimum information you should capture when surveying 

employees to evaluate a SIP program. You must conduct a separate survey for each 

of your registered worksites. 

If you are already administering a survey as part of a mandatory trip reduction 

ordinance or for other purposes, you might be able to use the information collected 

through that survey for this purpose. Contact your EPA Regional office. 

In some communities, a transportation agency (such as a regional planning agency 

or transportation management association) may be able to administer a survey that 

not only reports on mode share but also helps better understand the commuting 

needs of your employees. Employers may wish to add questions to the survey about 

other commuting services or options that employees desire, or benefits that would be 

useful in encouraging employees to try transit, ridesharing, walking or bicycling, or 

flexible work arrangements. 

Q: What are the steps for surveying employees? 

A: There are seven basic steps to conducting an employee survey: 

1. Determine when to conduct the employee survey 

2. Establish how the survey will be distributed 

3. Decide which employees to survey 

4. Determine how many employees to survey 

5. Inform employees of the survey and distribute survey to all eligible or sampled 

employees 

6. Collect the employee surveys and contact non-responders 

7. Compile the results of the employee survey 

Please see below for detailed information about each of these steps. 

Q: When should I conduct the survey? 

A: Employees should be surveyed about their commuting trips following a typical 

workweek. Surveys should not be distributed to employees the week following a 

holiday, after a group of employees have not been present at the worksite (e.g., 

during a corporate retreat), or after other circumstances that could affect employee 

commuter patterns. 

In addition to deciding when to conduct the survey, a deadline should be set for 

collecting surveys from employees. This deadline should be set to allow sufficient 

time to contact non-responders and determine the survey results. In general you 

40
should start surveying employees several months in advance of the date you have 

selected for reporting to EPA. 

Q: How should the survey be distributed? 

A: Surveys should be distributed in the manner that best suits your organization’s 

culture. Distribution options include the following: 

♦ Electronic distribution (e-mail) – appropriate for companies that regularly 

communicate in this manner 

♦ Mass distribution – sent to employees along with their paychecks, through a 

company newsletter, or via a special mailing 

♦	 Internet – an increasingly popular option, the questionnaire is accessed and 

filled out via the web. Responses can be automatically transferred to a 

database for analysis. If you can’t perform such a survey over your own 

network, EPA can host the questionnaire and capture and analyze the data for 

you. 

♦ Group administration – distribution at an employee meeting where the 

employees fill out the survey during the meeting 

♦ Individual administration – dissemination by an individual assigned to administer 

the survey to employees (most appropriate for smaller organizations) 

Electronic and mass distribution require less administration on the front-end, but 

often require more follow-up to ensure good results. Group or individual 

administration reduces the problems of non-responders and waiting for employees to 

submit their surveys, but requires additional administration time. 

Q: How do I decide which employees to survey? 

A: Employees who should be surveyed fall in any of the following categories: 

♦	 Employees who are on your organization’s payroll and assigned to your 

worksite, including night shift, or teleworking employees OR 

♦ Employees who have an assigned workstation at your site OR 

♦ Part-time employees who work half time or more (you are encouraged to include 

all part-time employees in order to get more accurate and useful information) OR 

♦ Contractors at your worksite who are not on your organization’s payroll but are 

allowed to take part in your organization’s benefits 

Q: How do I determine how many employees to survey? 

A: The number of employees to survey depends on the size of the work force at 

your worksite. 

If your worksite has fewer than 750 eligible employees:

All eligible employees should be surveyed. 

If your worksite has 750 or more eligible employees: 

You may survey a random sample of eligible employees. The goal of a random 

sample is to create unbiased results that can be generalized to the worksite as a 

whole without surveying each employee. Use the table below to determine the 

sample size required for a given number of eligible employees: 

41
Number of Eligible 

Employees 

Required 

Sample Size 

750 to 999 635 

1,000 to 1,249 706 

1,250 to 1,499 742 

1,500 to 1,999 813 

2,000 to 2,999 885 

3,000 to 3,999 956 

4,000 to 4,999 1,028 

5,000 to 9,999 1,063 

10,000 to 19,999 1,135 

20,000 or more 1,170 

You should pick the sample through random means of drawing names. 

Examples of survey methods that are NOT random samples include: 

•	 Distributing surveys to only employees who are in one business unit or on one 

floor of a building 

•	 Distributing surveys to 50 employees in each business unit or to 50 employees 

on each floor of a building 

•	 Handing out surveys to people who happen to be in the cafeteria on a given day 

or at a staff meeting on a given day 

The following methods may be used to create a random sample. 

If you have 750 to 1,625 eligible employees: 

Step 1: First, create a list of all survey-eligible employees. The list can be 

compiled using names organized alphabetically or by social security 

number. Do not use arrangements such that a recognizable group is 

divided into standard intervals. For example, do not use an arrangement 

where supervisors and staff members alternate. 

Step 2: Using the table above, determine how many eligible employees need to 

be surveyed. Calculate the number NOT to be surveyed by subtracting 

the number to be surveyed from the number of eligible employees. 

Step 3: Calculate the correct “interval” for removing names. This is done by 

dividing the number of eligible employees by the number of employees 

NOT to be surveyed. Round this number up to the nearest whole number, 

n. 

Step 4: Choose a starting number between 1 and n at random. For example, the 

numbers from 1 to n can be written on pieces of paper and put into a hat, 

and then one of these numbers is selected from the hat. 

Step 5: Using the number n calculated in step 3, count off each “nth” employee 

starting at the starting number calculated in step 4, with each of the “nth” 

employees taken out of the sample. The remaining employees will be 

surveyed. 

42
For example, with 800 employees, a survey of 635 employees is needed, and so 800 

– 635 = 165 employees who do not need to be surveyed. Dividing 165 employees 

by 800 employees produces the number 4.8, which rounds up to 5. The starting 

number selected in step 4 might be 2, so starting from the second employee, remove 

every 5th employee from the list. Survey the remaining employees. 

If you have 1,626 or more eligible employees: 

Step 1: First, create a list of all survey-eligible employees. The list can be 

compiled using names organized alphabetically or by social security 

number. Do not use arrangements such that a recognizable group is 

divided into standard intervals. For example, do not use an arrangement 

where supervisors and staff members alternate. 

Step 2: Using the table above, determine how many eligible employees need to 

be surveyed. 

Step 3: Calculate the correct sampling “interval.” This is done by dividing the 

number of eligible employees by the number of employees who must be 

surveyed (as indicated in the above table). Round this number down to 

the nearest whole number, n. 

Step 4: Choose a starting number between 1 and n at random. For example, the 

numbers from 1 to n can be written on pieces of paper and put into a hat, 

and then one of these numbers is selected from the hat. 

Step 5: Using the number n calculated in step 3, count off each “nth” employee 

starting at the starting number calculated in step 4, with each of the “nth” 

employees selected to be surveyed. 

For example, if the employer has 2,000 eligible employees, the table says that 885 

employees should be surveyed. The result of step 3 produces the number 2.26, 

which rounds down to 2. The starting number selected in step 4 might be 2. This 

means that every second employee in the employee list, starting with the second 

employee, should be selected for surveying. 

Because of the rounding down of the sampling interval, this method can produce 

random samples of more employees than the minimum required. If the employee list 

is organized by a factor expected to be unrelated to potential commuting patterns, 

such as an arrangement by social security number, then you can stop selecting 

employees from the list once you have the desired minimum sample size. On the 

other hand, if the list is organized by a factor that might be related to potential 

commuting patterns (such as by job type), you should continue selecting employees 

until you reach the end of the list in order to avoid having a biased sample. 

Q. What should I consider in informing employees of the survey and distributing 

it? 

A. Including a cover memo or letter that describes the survey and its purpose is 

essential. The memo or letter should emphasize why it is important that the survey 

be completed. For example, you might explain to employees that the information 

43
collected will help you better tailor your commuter benefits to employee needs and/or 

manage your program better. 

Special arrangements may have to be made to distribute and collect surveys from 

employees who work during off-hours, telecommute, or work part time. Also note that 

while you may consolidate the design and distribution of the survey, you must report 

your results separately for each registered worksite. 

Q: How many surveys do I need to receive back? 

A: You must try to receive a targeted percent of surveys for your results to be valid. 

The target percent applies to the number of surveys that are distributed, whether or 

not all employees are surveyed or a sample is used. 

For employers with 300 or more eligible employees:

A 70 percent or greater response rate from the survey should be achieved. 

Employers in states and localities with trip reduction ordinances have found a 70 

percent response rate attainable, and this level is needed to ensure confidence in the 

results. 

For employers with fewer than 300 eligible employees:

The target response rate depends on the number of employees, as shown in the 

table below:

Number of 

Eligible 

Employees 

Target 

Response 

Rate (%) 

99 or fewer 92 

100-199 85 

200-299 78 

The target response rate is higher for smaller employers in order to ensure the same 

level of statistical confidence among all employer size groups. A high response rate 

is often easiest for smaller employers since individual follow-ups with employees can 

be made. 

Q: How do I collect employee surveys and contact non-respondents? 

A: Employees should submit their completed surveys to a designated location or 

person by a specified deadline. One week after the surveys have been distributed (if 

sent out to individuals), determine how many have been returned. Normally, 

response drops off dramatically after one week. 

All non-responders should be reminded to submit the survey through a general 

notice to all survey recipients. Another copy of the survey may also be distributed in 

case the employee has misplaced the original survey. 

Tips for achieving a high response rate include: 

♦ Include a due date on the survey form 

♦ Let employees know why they are being surveyed and why it is important to the 

organization 

44
♦ Provide incentives for returning the survey, such as small gift items, such as 

mugs, magnets, or T-shirts, or coupons for discounts on local goods or services 

♦ Develop a contest where employees who return surveys can win gift certificates, 

transit passes, restaurant meals, or other prizes 

Q: How do I compile the results of the employee survey? 

A: Once you have collected the surveys, the next step is to tally the numbers from 

the employee surveys by category and by worksite. Please take care to include all of 

the collected responses in your totals. Enter the totals on the survey summary 

sheet, which is included in this Guide. 

Q: Whom can I contact for assistance with surveying employees? 

A: You can contact your account manager, the call the Best Workplaces for 

CommutersSM voicemail at 888-856-3131 or email bwc@epa.gov. Your organization 

may also be able to seek additional assistance from regional rideshare 

organizations, transportation management organizations, or outside contractors to 

provide assistance in either customizing or conducting your employee surveys. 

45