3. Transportation Demand Management Strategies

Transportation demand management (TDM) strategies focus on changing travel behavior - trip rates, trip length, travel mode, time-of-day, etc. - generally in order to reduce traffic during congested (peak) periods. TDM projects/programs generally reduce emissions of all pollutants by reducing vehicle trips and/or vehicle miles traveled (VMT) by personal motor vehicles, or by shifting trips from peak periods to less congested periods.

TDM strategies generally focus on reducing travel in light-duty vehicles (automobiles and light-duty trucks), which are large contributors to CO, VOC, and NOx emissions; consequently, these strategies may be most effective at targeting one or more of these pollutants.

Methodologies for analyzing the impacts of TDM strategies generally involve the following steps:

1. Estimate number of vehicle trips potentially affected by the strategy, based on the scope of the program.
2. Estimate reductions in vehicle trips, recognizing that some share of trips affected may not result in a reduction in vehicle trips.
3. Calculate reductions in VMT, both due to the elimination of vehicle trips and reductions in trip lengths.
4. Estimate shifts in travel times, as applicable.
5. Calculate emissions, based on emission factors reflective of the vehicle types affected, road types used by those vehicles, speeds, and whether or not vehicle trip cold starts are eliminated.

These strategies, and associated methodologies, are presented below. Some of the strategies covered in this section are addressed by EPA's "Best Workplaces for Commuters" program, and estimates of emissions impacts for these strategies can be derived from the COMMUTER Model, http://www.epa.gov/OMS/stateresources/policy/pag_transp.htm#cp and the accompanying guidance document, http://www.epa.gov/otaq/stateresources/policy/transp/commuter/420b05016.pdf.

Note: For most of the TDM strategies, the methodologies used in the sample calculations do not incorporate secondary or indirect emissions impacts from speed and volume changes or from increases in transit service that may be needed in response to a demand management program. These effects are not significant in most cases, but should be considered on a case-by-case basis.

1. Park-and-Ride Facilities

Strategy Overview

Park-and-ride facilities include the construction or expansion of parking lots where people can park their vehicles and then join a carpool, vanpool or transit service. Typically, park-and-ride facilities are used in suburban areas. This strategy reduces emissions by decreasing the number of single-occupancy vehicles on the road.

Emissions Impacts

By encouraging drivers to reduce VMT by sharing car trips or taking transit, park-and-ride lots reduce emissions of all pollutants associated with driving, as shown in the table below. However, the emissions benefits will not be proportional for all pollutants, since the use of a park-and-ride facility requires individuals to drive to the facility. As a result, this strategy does not reduce the number of vehicle cold starts that are taken, during which time the highest emissions output of CO, NOX, and VOCs are produced (in fact, it is possible that park-and-ride lots could lead to increased vehicle trip starts if people who used to pick each other up at individual homes now each drive to the park-and-ride lot).

Since park-and-ride facilities reduce VMT but not cold starts, they generally are less effective at reducing CO, NOX, and VOCs than other demand management strategies that reduce vehicle trip-making entirely. They can be effective, however, in reducing localized CO; for instance, by reducing vehicle trips into a central business district.

Table 3-1. Park-and-Ride Strategy-Overall Impact on Emissions

General Considerations

Factors affecting the level of emissions impacts include:

• The number of spaces available in the park-and-ride facility, and expected utilization
• The form of transportation previously used by commuters (i.e., extent to which people previously drove alone)⁹
• The average length of carpool/vanpool trips using the park-and-ride facility¹⁰

Park-and-ride facility impacts are typically analyzed using sketch planning methods. The calculation of emissions impacts should ideally account for any changes in trip lengths associated with driving to the park-and-ride lot (e.g., for instance, if someone drives one mile out of the way to access the park-and-ride) and any potential increase in trip starts associated with people who previously were picked up at home but now drive to the park-and-ride. However, these factors are generally very small and are not usually considered in simple sketch planning methods.

For EPA guidance on this strategy, see "Methodologies for Estimating Emissions and Travel Activity Effects of TCMs," http://www.epa.gov/ttnnaaqs/ozone/eac/epa-420-r-94-002_07-94.pdf. For more information on this strategy, see the EPA TCM Information Document, "Park-and-Ride/Fringe Parking." http://www.epa.gov/otaq/stateresources/policy/transp/tcms/park-fringepark.pdf.

Sample Projects

Sample 1: Adding spaces to an Existing Park-and-Ride Facility Without Transit

This example assumes an addition of parking spaces to an existing park-and-ride facility that is not served by transit, and is based on parameters for an expansion to a park-and-ride lot along Maryland 22 at Bynum Run Park in suburban Baltimore, Maryland. Emissions impacts are calculated using a simple sketch planning technique. The inputs assumed for the sample include:¹¹

• 60 parking spaces added
• 70 percent estimated utilization rate
• 80 percent of users previously drove alone
• 50 miles roundtrip average reduced by lot users (distance from lot to destination and return)
• 250 operating days per year

Step 1: Estimate expected lot use.
= (Spaces added to lot) x (estimated utilization rate)
= (60 spaces) x (0.70)
= 42 spaces

Step 2: Calculate expected number of people reducing driving.
= (Spaces used) x (share who previously drove alone)
= (42 spaces) x (0.80)
= 33.6 fewer drivers per day

Step 3: Calculate annual VMT reduction.
= (Number of fewer drivers per day) x (estimated round trip) x (operating days)
= (33.6 fewer drivers) x (50 mi) x (250 days)
= 525,000 annual VMT reduction

Step 2: Calculate reduction in emissions.
= (Running emission factor) x (reduction in VMT)

Table 3-2 shows the annual emissions impacts resulting from the implementation of the example strategy.

Table 3-2. Total Emissions Reduced (ton/year) from Park-and-Ride Example

Year	PM-2.5	PM-10	CO	NOx	VOCs	SOx	NH3
2006	0.01	0.01	4.09	0.41	0.34	<0 .01	0.06
2010	0.01	0.01	3.15	0.29	0.24	< 0.01	0.06
2020	0.01	0.01	2.17	0.14	0.13	< 0.01	0.06

Sample 2: New Park-and-Ride Lot served by Transit

This sample is comprised of a new park-and-ride lot with new transit services. This sample is based on a new lot added along the I-59 corridor in Birmingham, Alabama.¹² Emissions impacts are calculated using a simple sketch planning technique. The inputs assumed for the sample include:

• 100 parking spaces added
• 85 percent expected utilization
• 83 percent of users previously drove alone
• 12 miles expected trip length reduction, round trip
• 4 round-trip (8 one-way) commuter buses serving the lot per day
• 10.5 miles bus trip length
• 250 operating days per year

Step 1: Estimate expected lot use.

= (Historical utilization) x (spaces in lot)
= (0.85) x (100 spaces)
= 85 spaces

Step 2: Calculate the number of people reducing driving.

= (Expected lot use) x (percent of users who previously drove alone)
= (85 spaces) x (0.83)
= 71 auto trips reduced per day

Step 3: Calculate annual VMT reduction.
= (Trips reduced) x (average commute trip length) x (operating days)
= (71 trips) x (12 mi) x (250 days)
= 213,000 annual VMT reduction

Step 4: Calculate the auto emissions reductions from the project.

= (Annual VMT reductions) x (auto running emissions factor)

Step 5: Calculate the emissions from the new bus service.
= (number of bus trips) x (bus trip length) x (bus running emissions factor)
= (8 trips) x (10.5 miles) x (bus running emissions factor)

Step 6: Calculate total emissions reductions.
= (Auto vehicle emissions reduced) - (bus emissions)

Table 3-3 shows the annual emissions impacts resulting from the implementation of the example strategy.

Table 3-3. Total Emissions Reduced (ton/year) from Park-and-Ride Example

Year	PM-2.5	PM-10	CO	NOx	VOCs	SOx	NH3
2006	< 0.01	<0.01	1.64	0.12	0.14	< 0.01	0.02
2010	< 0.01	0.01	1.26	0.09	0.10	< 0.01	0.02
2020	< 0.01	0.01	0.87	0.05	0.05	< 0.01	0.02

2. High-Occupancy Vehicle Lanes

Strategy Overview

High Occupancy Vehicle (HOV) lanes are intended to maximize the person-carrying capacity of a roadway by altering the design and/or operation of the facility to provide priority treatment for HOVs, such as carpools, buses, and vans. By providing two important incentives-reduced travel time and improved trip time reliability-HOV facilities encourage travelers to shift from single occupancy vehicles to HOV use. This shift should reduce vehicle trips, vehicle miles traveled (VMT), and associated emissions from these activities. In addition, HOV lanes are designed to operate at faster speeds, even during peak periods, and so the strategy also results in an increase in travel speeds for vehicles using the HOV lane.

Emissions Impacts

HOV lanes affect air pollution emissions in several ways. First, restricting the additional lanes to certain vehicles encourages ridesharing among commuters, resulting in fewer vehicle trips and emissions of all pollutants. HOV lanes also increase travel speeds for HOV traffic that is able to utilize the lanes, and potentially along the entire roadway. Consequently, the speed changes may have different effects for different pollutants, and could even increase some emissions. Implementation of HOV lanes also could result in some additional emissions that may partially offset the benefits of vehicle trip reduction if some people who previously used transit now switch to carpools, thereby increasing the number of vehicles on the road. However, in general, HOV lanes would be expected to reduce all pollutants, as shown below in Table 3-4.

Table 3-4. High Occupancy Vehicles- Overall Impact on Emissions

PM-2.5	PM-10	CO	NOx	VOCs	SOx	NH3

General Considerations

Factors affecting level of emissions impacts include:

• Existing number of carpools and vanpools on the roadway
• The extent to which travelers shift from SOVs to HOVs, or from transit to HOVs
• Travel speeds without the HOV lane and with implementation of the new HOV lane
• Duration of HOV operational restrictions and the level of enforcement, which will affect compliance¹³

Emissions impacts of HOV lanes are often estimated using sketch planning methods. More complex tools and models are also available, such as simulation tools and travel demand models, to examine impacts on speeds and traffic patterns in more detail.

For EPA guidance on this strategy, see "Methodologies for Estimating Emissions and Travel Activity Effects of TCMs," http://www.epa.gov/ttnnaaqs/ozone/eac/epa-420-r-94-002_07-94.pdf. For more information, see the EPA TCM Information Document, "High Occupancy Vehicle Lanes,"http://www.epa.gov/otaq/stateresources/policy/transp/tcms/high_occvehicles.pdf.

Sample Project

Extension of an Existing HOV Lane

This sample is based on a project that extended HOV lanes by 2 miles on I-84 from East Hartford to downtown Hartford¹⁴.HOV lanes can be analyzed using various methods, including travel demand forecasting model approaches and vehicle queuing models. In this case, a sketch planning methodology is used to calculate the changes in emissions on the 2 mile segment of roadway, as well as additional emissions impacts associated with increased ridesharing for commuting (e.g., people who switch from driving alone to a carpool will affect their entire commute trip, not just the last two miles). The calculation relies on the following inputs (for simplicity, this example assumes no increase in bus use, only carpools, and that all carpoolers meet at a park-and-ride facility, so trip start emissions are not reduced, only running emissions):

• 2 mile addition to HOV lanes at HOV-2 requirement (minimum 2 persons per vehicle)
• 8,000 vehicles per hour on road segment during peak periods
• 6 hours with HOV restrictions in place per day (3 hours each direction)
• 9 mph average speed on roadway prior to implementation
• 35 mph average speed in HOV lane after implementation; no change in speed in general use lanes
• 15 percent of vehicles on roadway are HOVs prior to implementation
• 5 percent of SOVs switch to HOVs as a result of implementation
• 2.1 average vehicle occupancy in HOV lane
• 12 mile average commute trip length
• 250 operating days per year

Step 1: Estimate total traffic in corridor that are HOVs and SOVs during HOV enforcement hours, prior to implementation of lane expansion

= (Corridor traffic count per peak hour) x (hours with HOV restrictions) x (percent HOVs)
= (8,000 vehicles per hour) x (6 hours) x (0.15 HOVs) = 7,200 HOVs
(8,000 vehicles per hour) x (6 hours) x (0.85 SOVs) = 40,800 SOVs

Step 2: Estimate shift from SOVs to HOVs with lane expansion.

Reduction in SOV trips
= (SOV travelers) x (share that switch to HOVs)
= (40,800 SOVs) x (0.05)
= 2,040 reduced SOV trips

Increase in HOV trips
= SOV trip reduction / (average HOV occupancy)
= (2,040 reduced SOV trips) / 2.1
= 971 new HOV trips

Step 3: Estimate change in emissions on the expanded roadway segment by comparing no-build to build scenarios.

No build on segment
= (Total vehicle trips) x (trip length) x (auto running emissions factor at 9 mph) x (operating days)
= (48,000 vehicle trips) x (2 miles) x (auto running emissions factor at 9 mph) x (250 days)

Build on segment
= [(SOV trips) x (trip length) x (auto running emissions factor at 10 mph)] + [(HOV trips) x (trip length) x (auto running emissions factor at 35 mph)] x (operating days)
= [(40,800 - 2,040 SOV trips) x (2 miles) x (auto running emissions factor at 10 mph)] + [(7,200 + 971 HOV trips) x (2 miles) x (auto running emissions factor at
35 mph)] x (250 days)

Step 4: Calculate additional emissions reductions off the expanded segment.

Reduced SOV emissions
=(Reduced SOV trips) x (commute trip length - segment length) x (auto running emissions factor at 9 mph) x (operating days)
= (2,040 reduced SOV trips) x (12 miles - 2 miles) x (auto running emissions factor at 9 mph) x (250 days)

Added HOV emissions
(New HOV trips) x (commute trip length - segment length) x (auto running emissions factor at 35 mph) x operating days
(971 new HOV trips) x (12 miles - 2 miles) x (auto running emissions factor at 35 mph) x (250 days)

The following table shows the annual emissions impacts resulting from the implementation of the example strategy.

Table 3-5. Total Emissions Reduced (ton/year) from High Occupancy Vehicles Example

Year	PM-2.5	PM-10	CO	NOx	VOCs	SOx	NH3
2006	0.26	0.56	216	22.9	34.4	0.18	2.20
2010	0.25	0.55	174	16.0	22.8	0.17	2.20
2020	0.25	0.54	130	7.41	13.6	0.17	2.21

3. Ridesharing Programs/Incentives

Strategy Overview

Regional rideshare programs provide ride-matching services, employer outreach, and incentives to commute by carpool or vanpool (such as free gas cards, drawings, award programs, subsidies). Ridematching may be traditional (i.e., people establish regular carpool routines) or dynamic (real-time matching of individuals who want to travel to/from similar locations). The strategy encourages SOV commuters to share trips, thereby reducing vehicle trips and VMT.

Emissions Impacts

Ridesharing programs reduce emissions by decreasing the amount of VMT. Consequently, the programs should generally reduce emissions for all pollutants, as shown below in Table 3-6.

Table 3-6. Ridesharing Programs/Incentives- Overall Impact on Emissions

PM-2.5	PM-10	CO	NOx	VOCs	SOx	NH3

General Considerations

Factors affecting the level of emissions impact include:

• The number of new carpools/vanpools formed
• The extent to which people previously drove alone (as opposed to using transit)
• The length of carpool trip to pick up riders

Ridesharing impacts are typically analyzed using sketch planning methods or use of EPA's COMMUTER Model. Care should be taken to avoid double-counting benefits of these programs with other related programs, since ridesharing is often incorporated into employer-based transportation demand management programs and is often bundled with additional TDM strategies.

For EPA guidance on this strategy, see "Methodologies for Estimating Emissions and Travel Activity Effects of TCMs," http://www.epa.gov/ttnnaaqs/ozone/eac/epa-420-r-94-002_07-94.pdf. In addition, for more information on this strategy, see the EPA TCM Information Document, "Area-Wide Rideshare Incentives," http://www.epa.gov/otaq/stateresources/policy/transp/tcms/areawide_incentive.pdf, and the COMMUTER Model documentation, http://www.epa.gov/oms/stateresources/policy/transp/commuter/420b05017.pdf.

Sample Project

Regional Rideshare Program

This sample is based on a scenario where an area-wide ridesharing and incentive program was implemented by 45 percent of employers in the San Francisco-San Mateo-Redwood City Metropolitan Area.¹⁵ Ridesharing support programs include support for carpooling and vanpooling, and financial incentives include parking costs, transit fare/pass subsidies, or other financial incentives. A COMMUTER Model run was conducted using model default parameters and the specific inputs discussed below in the calculations.

Step 1: Estimate the number of commuters that will have access to new commuter options as a result of the ridesharing and incentives program.

For this example, the Bureau of Labor Statistics was used to estimate the number of office and non-office employees in the San Francisco-San Mateo-Redwood City Metropolitan Area. In this metropolitan area, there are approximately 500,000 office employees and 425,000 non-office employees.¹⁶

Step 2: Determine the typical strategies offered and participation rates.

In the COMMUTER Model, employer-supported commute programs in a geographic area are represented by inputting the employer participation rates at various support levels. The respective rates assumed in the base case and strategy implementation case are listed below.

Base case:

Program	No Participation	Level 1	Level 2	Level 3
Carpool	90 percent	10 percent	0	0
Vanpool	95 percent	5 percent	0	0
Transit	90 percent	10 percent	0	0
Bicycle	100 percent	0	0	0

Action case:

Program	No Participation	Level 1	Level 2	Level 3
Carpool	90 percent	0	10 percent	0
Vanpool	85 percent	0	10 percent	5 percent
Transit	82 percent	5 percent	10 percent	3 percent
Bicycle	95 percent	0	5 percent	0

The COMMUTER Model defines a Level 1 program as the provision of information activities plus a quarter-time transportation coordinator. A Level 2 program is defined as Level 1 plus in-house matching services (carpool and vanpool), work hours flexibility (transit), or bicycle parking and shower facilitates (bicycle). A Level 3 program includes Level 2 plus a half-time transportation coordinator plus preferential parking and flexible work schedules (carpool), vanpool development and operating assistance and preferential parking (vanpool), or on-site transit pass sales (transit).

Step 3: Estimate total change in vehicle trips and VMT.

According to the COMMUTER Model, the employer provided support programs would lead to a reduction of 506 vehicle trips and 0.3 percent reduction in VMT, or 8,097 vehicle miles.

Step 4: Estimate emissions reductions (average commute speed of 35 mph).

= [(Vehicle trips reduced) x (per trip emissions factor)] + [(VMT reduced x (per mile running emissions factor)]

Table 3-7 shows the annual emissions impacts resulting from the implementation of the example strategy.

Table 3-7. Total Emissions Reduced (ton/year) from Ridesharing Programs/Incentives Example

Year	PM-2.5	PM-10	CO	NOx	VOCs	SOx	NH3
2006	0.03	0.05	15.6	1.54	1.30	0.02	0.22
2010	0.02	0.05	12.0	1.09	0.91	0.02	0.22
2020	0.02	0.05	8.29	0.53	0.53	0.02	0.22

4. Vanpool Program

Strategy Overview

Particularly well suited for longer commutes, vanpools typically carry from seven to fifteen passengers, and operate weekdays, traveling between one or two common pick-up locations (typically a park-and-ride lot where a rider may leave their car, or a transit station) and the place of work. Vanpool programs typically provide vehicles owned by an organization to commuters who live in a common geographic area and who share an employment destination. The vans or buses may be operated by a driver or by the commuters themselves. Additionally, some programs provide outreach services to attract potential riders.

Emissions Impacts

Vanpools reduce emissions by decreasing vehicle miles that occupants would otherwise travel by auto. Although an individual van may produce more emissions than an individual auto, vanpools typically replace 7 to 15 auto trips each, and therefore should result in reductions of all pollutants, as show in Table 3-8. Since personal vehicles make up a larger share of on-road CO, VOCs, and NH3 emissions than PM or NOX, this strategy will be more effective as strategy to reduce CO, VOCs, and NH3, rather than other pollutants.

Table 3-8. Vanpool Strategy - Overall Impact on Emissions

PM-2.5	PM-10	CO	NOx	VOCs	SOx	NH3

General Considerations

The level of emissions impact depends on:

• The number of vanpools established through the program
• The extent to which vanpool riders previously were driving alone (vs. already carpooling)
• The extent to which vanpool riders drive to a vanpool pick-up location
• The average length of vanpool trips

Vanpool program impacts are typically analyzed using sketch planning methods. When analyzing vanpool programs, care should be taken to ensure that double-counting of emissions effects does not occur with ridesharing programs, employer-based TDM programs, and other related programs. These strategies may need to be assessed together as a new TDM strategy, instead of individual projects. For EPA guidance, see "Methodologies for Estimating Emissions and Travel Activity Effects of TCMs," http://www.epa.gov/ttnnaaqs/ozone/eac/epa-420-r-94-002_07-94.pdf.

Sample Projects

Sample 1: Subsidy of Commuter Vanpools

This sample is based on a vanpool subsidy program in California.¹⁷ Emissions impacts are calculated based on the following assumptions:

• 10 long-distance commuter vanpools
• Average of 11 people, 5 days in each vanpool
• Average distance of 48 miles, each way
• 5 miles is auto trip length to access vanpools
• 83 percent of the riders previously drove to work alone
• 75 percent of vanpool riders drive an average of 5 miles to the access point
• Vans are gas-operating vehicles
• 240 operating days per year

Step 1: Estimate daily vanpool ridership.

= (Number of vanpools) x (average number of riders)
= 10 vanpools x 11 riders
= 110 daily vanpool ridership

Step 2: Calculate auto trip starts reduced per year.

= (Daily vanpool riders) x (percent of riders who previously drove alone) x (1 - percent of riders who drive to access point) x (2 trip per day) x (days of operation)
= (110 vanpool riders) x (.83) x (.25) x (2 trips) x (240 days)
= 11,413 annual auto trip starts reduced

Step 3: Calculate auto VMT reduced per year.

= (Daily vanpool riders) x (percent of riders who previously drove alone) x (2 trips per day) x (days of operation) x { (average one-way trip length)
- [(percent of riders driving to access point) x (auto trip length to access point)]}
= (110) x (0.83) x (2) x (240) (48 miles - [(0.75) x (5 miles)])
= 1,939,212 annual VMT reduced

Step 4: Calculate emissions reductions from autos.

= [(Auto trips reduced) x (auto trip start emissions factor)] + [(auto VMT reduced) x (auto running emissions factor)]

Step 5: Calculate emissions resulting from operation of the vanpool

= (Number of vans) x (average van trip length) x (2 trips per day) x (days of operation) x (van running emissions factor)
= (10) x (48 mi) x (2) x (240) x (van emissions factor, including start)

Step 6: Calculate net emissions reduction

= (Auto emissions reduction) - (van emissions)

Table 3-9 shows the annual emissions impacts resulting from the implementation of the example strategy.

Table 3-9. Total Emissions Reduced (ton/year) from Vanpool Subsidy Example

Year	PM-2.5	PM-10	CO	NOx	VOCs	SOx	NH3
2006	0.02	0.05	14.6	1.30	1.22	0.02	0.21
2010	0.02	0.05	11.3	0.94	0.85	0.02	0.21
2020	0.02	0.05	7.70	0.49	0.45	0.02	0.21

Sample 2: Establishment of New Vanpools

This sample focuses on the establishment of new vanpools, which can occur due to financial incentives, provision of vans, or other services. This sample is based on a vanpool project in Dade County, Florida¹⁸ .The emissions calculation uses a sketch planning technique, relying on the following inputs:

• 30 vans are established (capacity of 8 or 15, avg. 11.5 seats per van)
• Vanpool staging area is walking/biking distance or pick-up service is provided
• 80 percent of participants previously drove alone
• 30 mile average distance to work, each way
• 240 operating days per year

Step 1: Estimate annual auto trips reduced.

= (Total number of vanpoolers) x (percent of riders who previously drove alone) x (2 trips per day) x (days of operation)
= (30 vans x 11.5 riders per van) x (0.80) x (2) x (240)
= 132,480 vehicle trips reduced

Step 2: Estimate annual auto VMT reduced.

= (Vehicle trips reduced) x (average distance to work)
= (132,480) x (30 mi)
= 4 million annual vehicle miles reduced

Step 3: Calculate emissions reductions from autos.

= [(Auto trips reduced) x (auto trip start emissions factor)] + [(auto VMT reduced) x (auto running emissions factor)]

Step 4: Calculate emissions resulting from operation of the vanpool.

= (Number of vans) x (average van trip length) x (2 trips per day) x (days of operation) x (van running emissions factor)
= (30) x (30 mi) x (2) x (240) x (van running emissions factor)

Step 5: Calculate net emissions reduction.

= (Auto emissions reduction) - (van emissions)

Table 3-10 shows the total annual amount of emissions reduced as a result of implementing this project.

Table 3-10. Total Emissions Reduced (tons/year) from Vanpool Program Example

Year	PM-2.5	PM-10	CO	NOx	VOCs	SOx	NH3
2006	0.02	0.07	31.9	1.47	2.04	0,03	0.42
2010	0.03	0.08	24.7	1.21	1.43	0.03	0.42
2020	0.04	0.09	16.6	0.83	0.77	0.03	0.42

5. Bicycle/Pedestrian Projects and Programs

Strategy Overview

Bicycle and pedestrian projects/programs include a wide range of investments and strategies to facilitate and encourage non-motorized travel. Examples of these strategies include: bicycle paths and lanes, sidewalks, bicycle racks or lockers, pedestrian urban design enhancements, bicycle share programs, and bicycle incentives. These projects can serve both commute and non-commute trips.

Emissions Impacts

Bicycle and pedestrian projects/programs should reduce all pollutants by reducing VMT; however, impacts are likely to be small given limited shifts from driving and relatively short trip distances. Improved connections to transit services, however, can result in reductions in longer vehicle trips. General impacts of bicycle and pedestrian projects are shown below in the table below.

Table 3-11. Bicycle/Pedestrian Projects - Overall Impact on Emissions

PM-2.5	PM-10	CO	NOx	VOCs	SOx	NH3

General Considerations

The level of emissions impact depends on:

• Extent to which the project increases use of bicycling or walking
• Extent to which new bicyclers/walkers previously drove alone (as opposed to using transit or other non-motorized mode)
• Vehicle trip length reduced (which may be longer than the actual bicycle/pedestrian trip if linked with transit)

Bicycle and pedestrian project impacts are typically analyzed using sketch planning methods. For EPA guidance on this strategy, see "Methodologies for Estimating Emissions and Travel Activity Effects of TCMs," http://www.epa.gov/ttnnaaqs/ozone/eac/epa-420-r-94-002_07-94.pdf. For more information, see the EPA TCM Information Document, "Bicycle and Pedestrian Programs," http://www.epa.gov/otaq/stateresources/policy/transp/tcms/bicycle_ped.pdf.

Sample Projects

Sample 1: Development of a New Bike Lane

This example includes development of a single 1.13 mile bike lane, and is based on a project in the San Francisco Bay Area, California, which included installation of new pavement, signage, and bike lane striping.¹⁹ The new bike lane provides residents bike access to education, employment, shopping, and transit. Within one-quarter mile of the project, there is a college, a shopping center, a light rail station, and an office building. The parameters of the project consist of:

• 1.13 miles of bike lanes, both sides
• 1.8 miles average bike trip
• 200 operating days

Step 1: Estimate auto trips reduced.

Auto trips reduced can be estimated in various ways, including use of bicycle/pedestrian factors associated with different types of surrounding land uses, studies of similar bicycle projects, or modeling.

In this case, consistent with methods developed by the California Air Resources Board, auto trips reduced are calculated as a function of average daily traffic (ADT) on the roadway.

= (ADT) x (Adjustment on ADT for auto trips replaced by bike trips) x (operating days)
= (20,000) x (0.0109) x 200
= 43,600

Step 2: Estimate VMT reduced.

= (Auto trips reduced) x (length of bike trips)
= (43,600) x (1.8)
= 78,480

Step 3: Calculate annual emissions reduction.

= [(Annual auto trip starts reduced) x (auto trips end factor)] + [(annual auto VMT reduced) x (auto VMT factor)]

Table 3-12 shows the annual emissions impacts resulting from the implementation of the example strategy.

Table 3-12. Total Emissions Reduced (tons/year) from Bike Lane Example

Year	PM-2.5	PM-10	CO	NOx	VOCs	SOx	NH3
2006	<0.01	<0.01	0.75	0.70	0.07	<0.01	<0.01
2010	<0.01	<0.01	0.59	0.05	0.05	<0.01	<0.01
2020	<0.01	<0.01	0.41	0.03	0.03	<0.01	<0.01

Sample 2: Walkway to transit

This is an example of a pedestrian connection to transit that results in VMT reductions substantially longer that the actual pedestrian walkway. This project is based on the Cleveland Walkway to Gateway, which provides a link for transit riders arriving at Tower City Center, the main shopping and entertainment area of downtown Cleveland, to the Gateway Sports and Entertainment Complex. The climate-controlled walkway, which is about a quarter mile long, was designed in part to stimulate transit ridership in the metro area and relieve traffic congestion, especially during sporting events.²⁰ Information on the project is as follows:

• .25 mile climate-controlled walkway
• 940,000 estimated users taking transit over 16-month study period (487 days)
• 70 percent of users would not have taken transit without the walkway
• 8 mile trip length average to the Gateway complex
• 50 percent of transit riders who use the walkway drive to a public transit station on the other trip end
• 1.5 average auto occupancy

Step 1: Estimate the daily increase in transit trips.

= (Number of transit riders who used the walkway for 16 months) / (number of days studied) x (percent of walkway users who would not have taken transit in absence of walkway)
= (940,000) / (487 days) x (0.70)
= 1,351 daily new transit trips

Step 2: Estimate the reduction in vehicle trip starts.

= [1-Fraction of people who drive to public transit stations) / (avg. vehicle occupancy)] x (increase in transit riders)
= [(1-0.5)/1.5] x (1,351 trips)
= 446 vehicle trip starts reduction

Step 3: Estimate VMT reduction.

= (Increase in transit riders/average vehicle occupancy) x (average trip distance)
= (1,351)/(1.5) x (8)
= 7,205 reduction in VMT

Step 4: Estimate emissions reductions.

= (Auto trip start reduction) x (auto trip start emissions factor)] + [(VMT reduction) x (auto running emissions factor)]

The table below shows the annual emissions impacts resulting from the implementation of the example strategy.

Table 3-13. Total Emissions Reduced (tons/year) from Walkway Example

Year	PM-2.5	PM-10	CO	NOx	VOCs	SOx	NH3
2006	0.05	0.10	26.1	2.79	2.46	0.03	0.39
2010	0.04	0.10	20.2	1.96	1.70	0.03	0.39
2020	0.04	0.10	14.0	0.96	0.91	0.03	0.39

6. New/Expanded/Increased Transit Service

Strategy Overview

New bus or rail services include any additions to the provision of services through the establishment of new routes, increased frequency, hours of operation or coverage of routes. Emissions reductions occur when the expanded service encourages people to replace driving trips with transit.

Improved transit service involves increasing the frequency or hours of service on existing transit routes. This strategy increases transit ridership and decreases auto trips in several ways. First, increased frequency of service generally results in increased ridership because transit becomes a more convenient transportation option. Waiting time for transit is reduced, leading to a faster trip (start to end). Second, increasing hours of service allows people to use the route at hours that were not previously available.

Emissions Impacts

New transit routes and increased transit service frequency or hours of operation should reduce emissions of all pollutants by reducing VMT. However, emissions benefits will not be proportional for all pollutants, since the buses also emit pollution, and diesel buses produce higher levels of NOx and PM per mile compared to autos. Moreover, if the new services do not substantially increase transit ridership, there may be no net emissions reductions. General impacts of transit service enhancements are shown below in the table below.

Table 3-14. Transit Service Enhancements- Overall Impact on Emissions

PM-2.5	PM-10	CO	NOx	VOCs	SOx	NH3

* = Generally reduces emissions, but has the potential to increase emissions

General Considerations

The level of emissions impact depends on:

• The number of additional buses in operation and their type
• The extent to which the new service causes an increase in transit ridership
• The extent to which new transit riders previously drove alone
• The extent to which new transit users drive to the transit station
• Length of vehicle trips reduced

These factors depend on supporting land use patterns, the availability of supporting facilities (e.g., transit station parking, bicycle racks), transit fares and parking prices, supporting services, and other factors. Transit service expansions are typically analyzed using sketch planning methods, based on transit ridership projections. EPA's COMMUTER Model can also be used to analyze the impacts of strategies, such as increased frequency of transit services. Some transit service expansions are combined with other complementary programs, such as transit marketing and incentives, or park-and-ride facilities, so the impacts of these programs should be considered together in order to avoid double-counting.

For EPA guidance on transit service expansion strategies, see "Methodologies for Estimating Emissions and Travel Activity Effects of TCMs," http://www.epa.gov/ttnnaaqs/ozone/eac/epa-420-r-94-002_07-94.pdf. For more information on this strategy, see the EPA TCM Information Document, "Improved Public Transit," http://www.epa.gov/otaq/stateresources/policy/transp/tcms/improved_transit.pdf.

Sample Projects

Sample 1: New Bus Route

This strategy is comprised of a new commuter shuttle route running during peak period on weekdays.²¹ The program includes the following assumptions:

• New service operates using a new diesel bus
• 18 riders average occupancy per bus
• 8 daily bus trips
• 75 percent of riders previously drove alone
• 25 percent of users use autos to access transit service
• 9.6 mile average auto round trip length
• 12 mile average bus round-trip
• 20 mph average speed
• 250 operating days

Step 1: Calculate increase in average ridership.

= (Estimated occupancy per bus) x (number of daily bus trips)
= (18 passengers) x (8 trips)
= 144 daily passenger-trips

Step 2: Calculate number of auto trip starts eliminated.

= (Average daily bus ridership) x (percent of riders who previously drove alone)
x (1- percent using auto to transit service)
= (144) x (0.75) x (1-.25)
= 81 daily auto trip starts eliminated

Step 3: Calculate auto VMT reduced.

= (Average daily ridership) x (1- portion of riders who did not previously drive) x {(average auto trip length)
- [(trip length for auto access to and from transit) x (portion using auto access to transit service)]}
= (144 passengers) x (0.75) x [(9.6 mi) - (0-0)]
= 1,037 daily VMT reduced

Step 4: Calculate transit bus emissions.

= (Daily bus trips) x (bus round trip miles) x (bus running emissions factor)
= (8) x (12 miles) x (bus emission factor)

Step 5: Calculate total annual emissions reduced.

= [[(Auto VMT reduced) x (auto running emissions factors)] + [(auto trip starts reduced)
x (auto trip start emissions factor)] - (bus emissions)] x (operating days)

The following table shows the annual emissions impacts resulting from the implementation of the example strategy.

Table 3-15. Total Emissions Reduced (tons/year) from Transit Service Enhancement Example

Year	PM-2.5	PM-10	CO	NOx	VOCs	SOx	NH3
2006	<0.01	<0.01	1.94	Increase 0. 05	0.18	<0.01	0.03
2010	<0.01	<0.01	1.60	0.13	0.12	<0.01	0.03
2020	<0.01	<0.01	1.11	0.05	0.07	<0.01	0.03

Sample 2: Expanded Bus Service

This strategy involves additional service on an existing bus route serving a bridge corridor in a major metropolitan area. The project includes the following assumptions:

• New service operates using 6 diesel buses
• 25 new riders average occupancy per new bus
• 8 daily bus trips
• 50 percent of riders previously drove alone
• nousers use autos to access transit service
• 16 mile average bus round trip
• 8 mile average auto trip length
• 250 operating days

Step 1: Calculate increase in average ridership.

= (Estimated occupancy per bus) x (number of daily trips per bus) x (number of buses)
= (25 passengers) x (6 trips) x (6 buses)
= 900 daily passenger-trips

Step 2: Calculate number of auto trip starts eliminated.

= (Average daily bus ridership) x (percent of riders who previously drove alone)
x (1- percent using auto to transit service)
= (900) x (0.50) x (1-0)
= 450 daily auto trip starts eliminated

Step 3: Calculate auto VMT reduced.

= (Average daily ridership) x (1- portion of riders who did not previously drive) x {(average auto trip length)
- [(trip length for auto access to and from transit) x ;(portion using auto access to transit service)]}
= (900 passengers) x (0.50) x [(8) - (0-0)]
= 3600 daily VMT reduced

Step 4: Calculate transit bus emissions.

= (Daily bus trips) x (bus round trip miles) x (bus running emissions factor)
= (8) x (16 miles) x (bus emission factor)

Step 5: Calculate total annual emissions reduced.

= [[(Auto VMT reduced) x (auto running emissions factors)] + [(auto trip starts reduced)
x (auto trip start emissions factor)] - (bus emissions)] x (operating days)

The following table shows the annual emissions impacts resulting from the implementation of the example strategy.

Table 3-16. Total Emissions Reduced (tons/year) from Transit Service Enhancement Example

Year	PM-2.5	PM-10	CO	NOx	VOCs	SOx	NH3
2006	<0.01	<0.01	1.94	Increase 0.05	0.18	<0.01	0.03
2010	<0.01	<0.01	1.60	0.13	0.12	<0.01	0.03
2020	<0.01	<0.01	1.11	0.05	0.07	<0.01	0.03

7. Transit Marketing, Information, and Amenities

Strategy Overview

Increased marketing, provision of more widely accessible transit information, and additional customer service may increase the number of people using public transportation each day. As for passenger amenities, the provision of such things as transit shelters, benches, maps, and visually pleasing aesthetics, or improving the comfort of buses and trains may be a supporting strategy to increase ridership. In addition, service enhancements such as improved transfer facilities and timing of transit services to reduce wait times during transfer may also increase ridership.

Emissions Impacts

Transit information/marketing/amenities will reduce all pollutants by encouraging shifts from driving to using transit, and thereby reducing VMT; these strategies do not involve provision of new bus service, and so there are no new bus emissions. General impacts are shown below in the table below:

Table 3-17. Transit Marketing - Overall Impact on Emissions

PM-2.5	PM-10	CO	NOx	VOCs	SOx	NH3

General Considerations

The level of emissions impact depends on:

• The extent to which ridership increases as a result of the marketing and other enhancements;
• The extent to which new riders previously drove alone;

These types of programs may result in behavior changes that produce reductions in emissions. However, careful documentation must be provided to demonstrate that the behavior change and resulting emission reductions were a result of the outreach program. This may not be quite so critical if this strategy is bundled with another transportation demand management strategy and the results are not specifically dependent on one strategy or another.

Emissions impacts of transit marketing, information, and amenities are typically analyzed using sketch planning methods. EPA's COMMUTER Model can be used to analyze some types of service improvements, such as increased information about schedules and real-time traveler information, which can be analyzed as a reduction in waiting times. Note that transit service enhancements and marketing are often implemented in combination with service expansions or other complementary programs; if this is the case, the impacts of these programs should be considered together in order to avoid double-counting of emissions benefits and account for the increase emissions from any service expansion.

Sample Project

Transit Amenities and Enhancements

This project assumes major improvements in transit system amenities, including additions of bus shelters, real-time bus information, and enhanced signage. It is based loosely on a sample transit route service improvement on Central Coast Area Transit (CCAT) Route 9 in California.²² The project assumes the following inputs:

• 51,680 increase in annual ridership
• 20.2 mile average home-to-destination trip
• 47 percent of riders shifted from driving alone
• 27 percent of riders shifted from carpooling and vanpooling with an average occupancy of 2.5, combined
• Each reduced driver eliminates 2 vehicle trips per day
• 255 operating days per year

Step 1: Estimate increased transit ridership.

= [(Annual rides) / (service weekdays)] / 2
= (51,680/255)/2
= 101 new riders per day

Step 2: Calculate daily vehicle trips reduced.

= (New daily riders) x (percent prior drive alone) x (roundtrip)
= (101) x (0.47) x (2)
= 95 vehicle trips reduced from SOV switch

= [(New daily riders) x (percent prior carpool/vanpool) / (avg. occupancy of carpool/vanpool)] x (roundtrip)
= [(101) x (0.27) / (2.5)] x (2)
= 18.6 vehicle trips reduced from HOV switch

Total daily vehicle trips reduced = 95 + 18.6 = 114

Step 3:Calculate vehicle miles of travel reduced.

= (Daily vehicle trips reduced) x (Avg. trip distance)
= (114) x (20.2)
= 2,303 miles per day

Step 4:Estimate emissions reductions.

= [(Auto trip end emissions factor) x (trips reduced)] + [(auto running emissions factor) x (miles reduced)] x (operating days)

Table 3-18 shows the annual emissions impacts resulting from the implementation of the example strategy.

Table 3-18. Total Emissions Reduced (tons/year) from Transit Service Enhancement Example

Year	PM-2.5	PM-10	CO	NOx	VOCs	SOx	NH3
2006	0.01	0.01	4.75	0.42	0.47	<0.01	0.07
2010	0.01	0.02	3.70	0.30	0.32	<0.01	0.07
2020	0.01	0.02	2.60	0.16	0.17	<0.01	0.07

8. Transit Pricing

Strategy Overview

Transit pricing strategies are designed to reduce the costs associated with using transit, thereby creating incentives for people to shift from other traveling modes. Fare reductions can be implemented system-wide, in specific fare-free or reduced fare zones, or offered through employer-based benefits programs which are fully or partially paid by the employer.

Emissions Impacts

By encouraging drivers to switch to transit, transit price reductions should reduce emissions of all pollutants, as shown in Table 3-19.

Table 3-19. Transit Pricing Strategy-Overall Impact on Emissions

PM-2.5	PM-10	CO	NOx	VOCs	SOx	NH3

Since rider response to fare changes is relatively inelastic and transit makes up only a small share of total trips in most urban areas, transit pricing projects by themselves will generally have limited impacts on VMT and emissions on a regional basis. However, when fare changes are implemented in conjunction with other supporting strategies, and particularly when focused on congested areas with good transit service such as downtowns, universities, and major urban employment concentrations, the effect on traffic and emissions can be more notable.

General Considerations

The level of emissions impact depends on:

• The increase in transit ridership associated with the fare reduction, which in turn, depends on auto availability; parking costs; and the frequency, comfort, and perceived safety of transit services
• The extent to which new transit riders were previously driving, versus substituting for walking or bicycling trips or simply taking new trips

Transit pricing projects are often analyzed using sketch planning methods, such as by applying a transit fare pricing elasticity, which estimate the percent increase in transit ridership associated with a given percent reduction in transit fares. EPA's COMMUTER Model can also be used to analyze the effects of transit price changes on commuter routes, or employer-subsidized transit programs. For EPA guidance on transit pricing, see "Opportunities to Improve Air Quality through Transportation Pricing Programs," http://www.epa.gov/otaq/market/pricing.pdf,

"Methodologies for Estimating Emissions and Travel Activity Effects of TCMs," http://www.epa.gov/ttnnaaqs/ozone/eac/epa-420-r-94-002_07-94.pdf and the EPA and DOT"s document, "Technical Methods for Analyzing Pricing Measures to Reduce Transportation Emissions," http://www.epa.gov/otaq/stateresources/policy/transp/tcms/anpricng.pdf.

Sample Projects

Sample 1: Fare Free Transit

This example is based on results from several fare-free transit programs, including a system-wide demonstration in Austin, Texas and a fare-free demonstration during off-peak periods in Denver.²³ The inputs for the calculation of emissions benefits on the project are as follows:

• 75 percent ridership increase
• 46 percent of new riders switch from driving
• None of the new riders drive to the transit service
• Average trip length of 6 miles
• 30 mph average speed
• 250 days of effectiveness per year
• No additional transit service (no new buses needed to meet this increase)

Step 1: Estimate the increase in transit ridership from the program.

= (Existing transit ridership) x (percent increase in ridership)
= (10,000) x (0.75)
= 7,500 new transit riders

Step 2: Calculate the daily reduction in vehicle trip starts.

= (Increase in daily transit ridership) x (portion who previously drove) x (1- portion using auto to access transit service)
= (7,500) x (0.46) x (1-0)
= 3,450 auto trips reduced per day

Step 3: Calculate auto VMT reduced.

= (Increase in daily transit ridership) x (portion who previously drove) x (average trip length)
= (7,500) x (0.46) x (6 mi)
= 20,700 vehicle miles reduced per day

Step 4: Calculate annual emissions reduced.

= [(Auto trip starts reduced) x (auto trip start emissions factor)] + [(auto VMT reduced) x (auto running emissions factor)] x (days per year)

The table below shows the annual emissions impacts resulting from the implementation of the example strategy.

Table 3-20. Total Emissions Reduced (tons/year) from Fare Free Transit Example

Year	PM-2.5	PM-10	CO	NOx	VOCs	SOx	NH3
2006	0.07	0.15	41.9	4.29	3.91	0.05	0.57
2010	0.07	0.14	33.0	2.36	2.74	0.04	0.58
2020	0.06	0.14	23.1	1.48	1.48	0.04	0.58

Sample 2: Transit Pass Program

This example is based on a universal transit pass program called Eco Pass offered by the Santa Clara Valley Transit Authority, which offers significant fare discounts for participating employers.²⁴ The emissions benefits of the project are calculate based on the following inputs:

• 26,400 increase in participants (1997-2001)
• 61 percent of Eco Pass recipients are new transit riders
• 96 percent of the new transit riders reported previously driving to work
• 250 days of effectiveness per year
• No additional transit service (no new buses needed to meet this increase)

Step 1: Estimate the increase in transit riders from the program.

= (New pass program participants) x (share new to transit)
= (26,400) x (0.61)
= 16,104 new transit riders

Step 2: Calculate the daily reduction in vehicle trip starts.

= (Increase in daily transit ridership) x (portion who previously drove) x (1- portion using auto to access transit service) x (2 trips per day)
= (16,104) x (0.96) x (1-0.25) x (2)
= 23,190 daily auto trip starts reduced

Step 3: Calculate daily auto VMT reduced.

= (Increase in daily transit ridership) x (portion who previously drove) x (average trip length) x (2 trips per day)
= (16,104) x (0.96) x (6 mi) x (2)
= 185,518 daily vehicle miles reduced per day

Step 4: Calculate annual emissions reduced.

= [(Auto trip starts reduced) x (auto trip start emissions factor)] + [(auto VMT reduced) x (auto running emissions factor)]

The table below shows the annual emissions impacts resulting from the implementation of the example strategy.

Table 3-21. Total Emissions Reduced (tons/year) from Transit Pass Program Example

Year	PM-2.5	PM-10	CO	NOx	VOCs	SOx	NH3
2006	0.61	1.30	378	40.2	38.1	0.43	5.13
2010	0.59	1.27	163	28.5	26.5	0.39	5.15
2020	0.58	1.27	119	14.0	14.4	0.39	5.16

9. Parking Pricing/Management

Strategy Overview

These strategies change the cost and/or convenience associated with driving a private vehicle, through pricing and management of parking on either end of the trip. While some policies increase the cost of parking through taxes or implementation of parking fees, some strategies reduce the supply of spaces through the creation of parking maximums for new development, regional parking caps, peak-hour parking bans, or curb-parking restrictions. Parking supply limits not only can increase the direct price of parking, but can also reduce the likelihood of finding parking at destinations, and may require walking one or more blocks for parking. Some parking management programs are designed to create an incentive for ridesharing, such as preferential spaces for carpools/vanpools or reduced parking prices for carpools/vanpools. All of these strategies reduce emissions by reducing the number of vehicle trips taken.

Emissions Impacts

Parking pricing and management strategies should reduce emissions of all pollutants by reducing vehicle trips and VMT. General impacts of parking pricing/management enhancements are shown below.

Table 3-22. Parking Pricing/Management - Overall Impact on Emissions

PM-2.5	PM-10	CO	NOx	VOCs	SOx	NH3

General Considerations

The level of emissions impact depends on:

• The extent to which parking pricing or restrictions are applied
• The elasticity of VMT in response to the price of parking
• The availability of free or less-expensive parking on nearby streets, which could diminish the program's effectiveness; parking permit programs, use of short-term parking meters, and other strategies can be implemented to reduce the potential for this spillover

Parking pricing and supply limit strategies may be analyzed using sketch planning methods, or EPA's COMMUTER Model if the parking strategy focuses on work trips (including increased parking charges and preferential parking for carpools/vanpools). For EPA guidance on this strategy, see "Methodologies for Estimating Emissions and Travel Activity Effects of TCMs," http://www.epa.gov/ttnnaaqs/ozone/eac/epa-420-r-94-002_07-94.pdf. For more information, also see TCM Information Document, "Parking Management," http://www.epa.gov/otaq/stateresources/policy/transp/tcms/parkingmgmt.pdf, and "Opportunities to Improve Air Quality through Transportation Pricing Programs," http://www.epa.gov/otaq/market/pricing.pdf.

Sample Projects

Sample 1: Regional Parking Supply Limits

This example reflects a downtown parking policy that limits the supply of parking. It is based on a program that had been operating in Portland, Oregon that set maximum ratios for the number of parking spaces per square foot of office space, based on the type of development and proximity to transit (ratios ranged from 0.7 to 1.0 space per 1000 square feet, compared to typical ratios of 4 spaces per 1000 square feet)²⁵. Several different approaches can be used to analyze a program such as this, including examination of changes in parking prices, parking per employee, or parking per square foot.; A simple sketch planning method is used for this calculation, based on the following factors:

• 92,000 employees working downtown
• 0.44 off-street parking spaces per employee available before the policy
• 0.38 off-street parking spaces per employee after the policy
• 5 mile average home-to-work commute
• 250 operating days

Step 1: Calculate reduction in parking supply due to the program.

= [(parking spaces per employee without policy) - (parking spaces per employee with policy)] x (number of employees)
= (0.44-0.38) x (92,000 employees)
= 5,520 fewer parking spaces

Step 2: Calculate reduction in daily vehicle trips.

= (fewer parking spaces) x (2 vehicle trips per day)
= (5,520) x (2)
= 11,040 vehicle trips reduced

Step 3: Calculate reduction in daily VMT.

= (vehicle trip reduction) x (average commute trip length)
= (11,040) x (5 miles)
= 55,200 vehicle miles reduced

Step 4: Calculate annual emissions reduction.

= [(vehicle trips reduced) x (trip start emission factor) + (VMT reduced) x (running emissions factor)] x commute days per year
= [(11,040) x (trip start emission factor) + 55,200 x (running emissions factor)] x 250

The table below shows the annual emissions impacts resulting from the implementation of the example strategy.

Table 3-23. Total Emissions Reduced (tons/year) from Parking Pricing/Management Example

Year	PM-2.5	PM-10	CO	NOx	VOCs	SOx	NH3
2006	0.18	0.39	117	12.2	11.7	0.13	1.53
2010	0.18	0.38	91.8	8.61	8.09	0.12	1.53
2020	0.17	0.38	64.8	4.29	4.24	0.12	1.53

Sample 2: Parking Cash out

In this example, an employer offers a parking cash out incentive (i.e., provides employees that do not park at work a financial incentive) to encourage ridesharing, transit, and walking and bicycling, instead of driving alone to work²⁶. The EPA's COMMUTER Model can be used to analyze the impacts of the program as a reduction in the price of alternatives to parking.; A simple sketch planning approach is shown below, based on inputs from the North Central Texas Council of Governments as follows:

• 100 decrease in daily vehicle trips due to implementation
• 14.11 mile average trip length
• 260 work days (days of operation)

Step 1: Calculate decrease in daily VMT.

= (Daily vehicle trips) x (average trip length)
= (100) x (14.11)
= 1411 daily VMT reduction

Step 2: Calculate annual running emissions reduction.
= (Daily VMT reduction) x (days of operation) x (running emissions factor)
= (1411) x (260) x (running emissions factor)

Step 3: Calculate annual trip starts reduction.

= (Daily vehicle trip reduction) x (days of operation) x (auto trip starts emission factor)
= (100) x (260) x (auto trip starts emission factor)

Step 4: Calculate annual total emissions reduction.

= (Auto running emissions reduction) + (auto trip starts emissions reduction)

The table below shows the annual emissions impacts resulting from implementation of the example strategy.

Table 3-24. Total Emissions Reduced (tons/year) from Parking Pricing/Management Example

Year	PM-2.5	PM-10	CO	NOx	VOCs	SOx	NH3
2006	<0.01	0.01	2.95	0.29	0.25	<0.01	0.04
2010	<0.01	0.01	2.27	0.21	0.17	<0.01	0.04
2020	<0.01	0.01	1.57	0.10	0.09	<0.01	0.04

10. Road Pricing

Strategy Overview

Road pricing strategies reduce emissions by changing the costs to consumers operating private vehicles. Examples include new or increased tolls on roads, high occupancy toll (HOT) lanes, or cordon pricing. As a price-based disincentive to vehicular travel, these policies would cause travelers to shift to other modes or share rides, with resulting emissions reductions. These strategies may also encourage shifts in travel by time of day if developed as a congestion pricing mechanism. Strategies may also impact travel speeds along congested corridors, with associated emissions impacts.

Emissions Impacts

To the extent that pricing encourages reduced vehicle travel by shifting trips to alternate modes, emissions reductions will result across all pollutants. However, if speeds along roadways are also impacted as a result or if a congestion pricing strategy is implemented, effects will not be proportionate for all pollutants. Congestion pricing is designed to increase tolls during peak hours and thereby shift traffic to off-peak periods. In general, congestion pricing will reduce all pollutants, since vehicles traveling under congested travel conditions generally emit more pollution than under non-congested conditions; still, depending on speed changes, there is the possibility of an increase. General impacts of road pricing are shown below.

Table 3-25. Road Pricing - Overall Impact on Emissions

PM-2.5	PM-10	CO	NOx	VOCs	SOx	NH3

* Generally reduces emissions, but has the potential to increase emissions (in the case of congestion pricing where a new priced lane is added, and the pricing may shift drivers to alternate routes or shift travel to off-peak hours, in which case the increased speeds might be associated with increases in some emissions)

General Considerations

The level of emissions impact depends on:

• The level of the price increase
• The extent to which traffic is diverted to other roads, thereby increasing congestion in other locations
• The response to the increase in the price of driving, which will vary based on the existing traffic levels and the availability of alternatives
• The scope and timing of pricing, which may encourage shifts in travel by time of day, rather than a reduction in driving
• Whether drivers take shorter trips rather than eliminating them completely

Travel demand forecasting models can capture some of the impacts of road pricing strategies on mode shifts and diversion of traffic, and can be used as a basis for analyzing emissions impacts. A much simpler sketch planning analysis is shown in the sample calculation below. For EPA information on road pricing, see "Opportunities to Improve Air Quality through Transportation Pricing Programs," http://www.epa.gov/otaq/market/pricing.pdf.

Sample Project

Fixed Rate Tolls

In this example, a $0.75 toll charge is implemented on regional freeways²⁷. Calculations regarding emissions impact of the project include the following assumptions:

• $0.75 toll
• 29,988,000 average daily VMT
• $0.115 average out-of-pocket cost per mile
• 8.4 mile average vehicle trip
• Price elasticity of travel is -0.25
• 365 operating days per year

Step 1: Calculate expected percentage vehicle mile reduction.

= (Percent increase in cost per vehicle mile) x (price elasticity of travel²⁸)
= {[($0.75)/(8.4 mi)] / ($0.115)]} x (-.25)
= .194

Step 2: Calculate expected reduction in daily VMT.

= (Percent reduction) x (daily VMT)
= (.194) x (29,988,000)
= 5,817,672

Step 3: Calculate trip starts emission reductions.

= (Percent reduction) x [(daily VMT) / (average trip length)] x (365 days/year) x (trip starts emissions factor)
= (.194) x (3,570,000) x (trip starts emissions factor)

Step 4: Calculate annual running emissions reductions.

(Daily VMT reduction) x (365 days/year) x (auto running emissions factor)
= (5,817,672) x (365) x (auto running emissions factor)

Step 5: Calculate total annual emissions reductions.

(Auto trip starts emissions reduction) + (auto running emissions reduction)

The table below shows the annual emissions impacts resulting from implementation of the example strategy.

Table 3-26. Total Emissions Reduced (tons/year) from Road Pricing Example

Year	PM-2.5	PM-10	CO	NOx	VOCs	SOx	NH3
2006	27.8	59.7	21,297	1,773	1,096	19.7	235
2010	27.8	58.7	16,332	1,254	783	19.7	236
2020	26.4	58.0	11,226	614	415	19.7	236

11. VMT-based Pricing

Strategy Overview

This measure would impose fees based on miles driven. The fees could be collected annually through the vehicle registration process, with mileage calculated through odometer readings. Alternatively, under a Pay-As-You-Drive (variable price) auto insurance program, insurance premiums would be charged with a per-mile component, and could be levied on a monthly or semi-annual basis. VMT based pricing is intended as a price-based disincentive to vehicular travel, causing travelers to shift to other modes, share rides, avoid trips, or shorten trip lengths with resulting reductions in mobile source emissions.

Emissions Impacts

To the extent that VMT pricing encourages reduced vehicle travel, emissions reductions will result across all pollutants. Unlike road pricing strategies, however, the impact on vehicle travel speed will be less, since the pricing is not focused on specific road facilities.

General impacts of VMT-based pricing are shown below.

Table 3-27. VMT-based Pricing - Overall Impact on Emissions

PM-2.5	PM-10	CO	NOx	VOCs	SOx	NH3

General Considerations

The level of emissions impact depends on:

• The level of the per mile charge
• The response to the increase in the price of driving, which may be affected by the availability of alternatives to driving and the process for collecting fees²⁹

VMT-based pricing programs have typically been analyzed using sketch-planning methods, relying on travel price elasticities. For more information, see EPA's document, "Opportunities to Improve Air Quality through Transportation Pricing Programs," http://www.epa.gov/otaq/market/pricing.pdf.

Sample Project

Pay As You Drive Insurance

The following is a hypothetical example of a Pay as You Drive insurance program in the Dallas-Fort Worth area. In this scenario, the following assumptions have been made:³⁰

• 173,003,248 daily vehicle miles are traveled daily by light-duty vehicles in region
• 10 percent of drivers participate in program
• $.06 charge per mile
• 9.7 percent travel reduction results from $.06 charge (calculated based on travel price elasticity)
• 365 operating days per year

Step 1: Calculate daily reduction in vehicle miles traveled.

= (Daily vehicle miles) x (percent participation) x (percent reduction)
= (173,003,248) x (.10) x (.097)
= 1,678,131 daily vehicle miles reduced

Step 2: Calculate annual emissions reduction.

= (Daily VMT reduction) x (auto running emissions factor) x (operating days)

The following table shows the annual emissions impacts resulting from implementation of the example strategy.

Table 3-28. Total Emissions Reduced (tons/year) from VMT-based Pricing Example

Year	PM-2.5	PM-10	CO	NOx	VOCs	SOx	NH3
2006	8.04	17.2	4,694	493	439	5.70	67.8
2010	7.81	17.0	3.635	347	304	5.20	68.1
2020	7.61	16.7	2,530	170	163	5.19	68.1

12. Fuel Pricing

Strategy Overview

This emissions reduction strategy would increase the tax rates applied to retail sales of motor fuels. Emissions reductions are achieved as drivers shift travel to other modes, share rides, reduce trips, or take shorter trips as a result of the higher costs of vehicle travel. As fuel pricing also creates an incentive for purchasing more fuel efficient vehicles, overall vehicle stock changes may further affect emissions over the long-term.

Emissions Impacts

To the extent that fuel pricing reduce VMT, fuel pricing strategies will reduce all pollutants; however, unless fuel price increases are large, impacts on VMT may be minor. General impacts of fuel pricing are shown below.

Table 3-29. Fuel Pricing-Overall Impact on Emissions

PM-2.5	PM-10	CO	NOx	VOCs	SOx	NH3

General Considerations

The level of emissions impact depends on:

• The level of the fuel tax increase
• Drivers' response to the increase in fuel prices, which will vary based on project specifics and local conditions, such as land use patterns and the availability of travel alternatives
• The extent to which fuel price increases affect vehicle purchase decisions Whether drivers take shorter trips rather than eliminating them completely

It should be noted that gas taxes are often viewed as politically unacceptable, particularly large tax increases that would be necessary to affect travel demand significantly. The emissions impacts of fuel pricing can be analyzed using sketch-planning methods, relying on travel price elasticities. For more information, see EPA's document, "Opportunities to Improve Air Quality through Transportation Pricing Programs," http://www.epa.gov/otaq/market/pricing.pdf.

Sample Project

$0.25 per gallon Fuel Tax increase

This regional fuel tax increase strategy includes the following assumptions:³¹

• $0.25 proposed increase in price per gallon
• $210 annual cost to drivers averaging 15,000 miles
• 75 million estimated daily vehicle miles of travel for Denver region
• $0.115 average out-of-pocket vehicle cost per mile
• -0.2 price elasticity for travel³²
• 8.4 mile average vehicle trip
• 17.8 mpg average fuel efficiency
• 365 operating days per year

Step 1: Calculate expected percent reduction in VMT

= (Percent increase in cost per vehicle mile) x (price elasticity of travel)
= [($.25/17.8)] / ($0.115) x (-.2)
= - 0.024

Step 2: Calculate expected reduction in daily VMT

= (Percent reduction) x (daily VMT)
= (.024) x (75,000,000 miles)
= 1,800,000 miles

Step 3: Calculate annual trip starts emission reductions

= (Percent reduction) x [(daily VMT) / (average vehicle trip)] x (trip starts emissions factors)
= (.024) x [(75,000,000) / (8.4)] x (365 days/year) x (auto trip starts emissions factors)
= 78,214,285 x (auto trip starts emissions factors)

Step 4: Calculate annual running emissions reductions

= (Daily VMT reduction) x (365 days/year) x (auto running emissions factor)
= (1,800,000) x (365) x (auto running emissions factor)
= (657,000,000) x (auto running emissions factor)

Step 5: Calculate total annual emissions reductions

= (Auto trip starts emissions reduction) + (auto running emissions reduction)

The following table shows the annual emissions impacts resulting from the implementation of the example strategy.

Table 3-30. Total Emissions Reduced (tons/year) from Fuel Pricing Example

Year	PM-2.5	PM-10	CO	NOx	VOCs	SOx	NH3