United States Office of Air and Radiation 400-R-92-006 

Environmental Protection (ANR-443) March 1992 

Agency Washington, DC 20460 

Air 

f>EPA Transportation Control Measure 

Information Documents 
Prepared for 

U.S. Environmental Protection Agency 

Office of Mobile Sources 

March 1992 

Transportation Control Measure

Information Documents 

Prepared by 

Cambridge Systematics, Inc. 
TRANSPORTATION CONTROL MEASURE

INFORMATION DOCUMENTS

Contract No. 68-D9-0073 

Work Assignment No. II-8 

Prepared for 

U.S. Environmental Protection Agency 

Office of Mobile Sources 

by 

Cambridge Systematic^, Inc. 

222 Third Street 

Cambridge, Massachusetts 02142 

with 

Comsis Corp. 

K.T. Analytics, Inc. 

Deakin, Harvey, Skabardonis 

March 1992 
Preface 

The Environmental Protection Agency is required under Section 108(f) of the Clean Air 

Act, as amended in 1990, to prepare information "regarding the formulation and emission reduction potential of transportation control measures related to criteria pollutants 

and their precursors." These information documents have been developed "in consultation with the Secretary of Transportation, and after providing public notice and opportunity for comment." 

This report constitutes information documents for the following sixteen categories of 

transportation control measures: 

1. Trip Reduction Ordinances 

2. Employer-Based Transportation Management Programs 

3. Work Schedule Changes 

4. Area-wide Rideshare Incentives 

5. Improved Public Transit 

6. High Occupancy Vehicle Facilities 

7. Traffic Flow Improvements 

8. Parking Management 

9. Park-and-Ride/Fringe Parking 

10. Bicycle and Pedestrian Programs 

11. Special Events 

12. Vehicle Use limitations/Restrictions 

13. Accelerated Retirement of Vehicles 

14. Activity Centers 

15. Extended Vehicle Idling 

16. Extreme Low-Temperature Cold Starts 

This Preface is immediately followed by a table identifying examples of the kinds of 

transportation control measures that can be included in each of the sixteen categories. 

The report then follows with a Summary section that includes a discussion of implementation experience with transportation control measures, along with summaries of 

each of the individual TCMs. A Transportation/Air Quality Background Information 

Preface 1 
chapter then summarizes pertinent background information on the relationships 

between transportation and air quality. This section defines basic technical consid­ erations important to the development, analysis, and evaluation of transportation 

control measures. 

Each individual transportation control measure is described using the following basic 

structure: 

1. Definition and major variations of measure. 

2. Summary description of pertinent examples. 

3. Transportation, emissions, and air quality impacts. This discussion is quantitative in 

nature whenever possible, and identifies key factors that determine the magnitude of 

expected impacts. 

4. An estimate of expected capital and operating costs, other important impacts, and 

principal travel markets affected. Major areas of uncertainty also are identified. 

5. Requirements to achieve effective implementation, including an assessment of major 

institutional and political considerations and a discussion of factors affecting the 

transferability of findings among urban areas. 

6. Bibliography of selected references. 

The trip reduction ordinance information document contains, in addition, a model or­ dinance that can be used as the basis for developing area-specific regulations. 

Several individuals and organizations have contributed to the development of these 

documents, including the following: 

Cambridge Systematics, Inc. Comsis Corporation 

John H. Suhrbier EricN.Schreffler 

Samuel T. Lawton 

Susan Jones Moses Deakin, Harvey, Skabardonis 

Robert A. Lepore Elizabeth A. Deakin 

Samuel N. Seskin 

David B. Reinke K.T. Analytics, Inc. Lance R. Grenzeback Kiran Bhatt 

Deborah A. Dagang Thomas J. Higgins 

Joseph A. Moriarty 

Georgia Institute of Technology 

Michael D. Meyer 

Direction from the U.S. Environmental Protection Agency has been provided by Mark 

Simons, and initially by Gary Hawthorn. The information document on Accelerated 

Retirement of Vehicles was prepared by Will Schroeer of EPA's Office of Policy, Plan­ ning and Evaluation. 

Preface 
Preliminary drafts of these Section 108(0 information documents were reviewed by the 

Transportation Control Measure Panel of the National Association of Regional Council's 

Clean Air Project. The following individuals participated in this review and are responsible for many of the changes incorporated in this March, 1992 publication: 

Sarah Siwek, Chair Los Angeles County Transportation Commission 

Chris Brittle Metropolitan Transportation Commission 

Ray Ruggieri New York Metropolitan Transportation Council 

Charles Goodman Baltimore Regional Council of Governments 

Jon Williams Washington, D.C. Council of Governments 

William Blackmer California Department of Transportation 

Charles Howard Washington State Department of Transportation 

Martin Robins New Jersey Transit 

Richard Roberts Port Authority TransHudson (PATH) 

Karen Kudebeh Colorado Department of Health 

Wallace Krawitzky New York State Department of Environmental 

Conservation 

Larry Filler Transit Center (New York) 

Michael Morris North Central Texas Council of Governments 

William Knight Toledo Metropolitan Area Council of Governments 

John Amberger Southeast Michigan Council of Governments 

Andrew Plummer Chicago Area Transportation Study 

Susan Pultz Metropolitan Transportation Commission 

Ron Roggenburk Delaware Valley Regional Planning Commission 

Mark Howard National Association of Regional Councils 

Manager, Clear Air Project 

Preface 
Transportation Control Measure (TCM) 

Typology 

I. Trip Reduction Ordinances 

A. Special Use Permits 

6. Negotiated Agreements 

C. Trip Reduction Goals 

D. Mandated Ridesharing and Activity Programs 

E. Transportation Management Funds and Districts 

F. Requirements for Adequate Public Facilities 

G. Conditions of Approval for New Construction 

H. Applicability 

1. New Development versus Existing Employers 

2. Variation by Employment Size 

3. Phase-In-Provisions 

n. Employer-Based Transportation Management Programs 

A. On-site Employer Transportation Coordinator 

B. Transit/Rideshare Services 

1. Provide HOV Shuttle Services Between Company Facilities 

2. Centralized Vanpool/Carpool Matching Service 

3. Rideshare/Transit Marketing/Information Programs 

4. Designated Transportation Coordinator 

5. HOV Priority Parking 

6. Vanpool/Subscription Bus Financing 

7. Subscription Buses or Buspooling 

8. Midday and Park-and-Ride Shuttles 

9. Guaranteed Ride Home 

C. Bicycle and Walking 

D. Employee Financial Incentives 

1. Subsidize Transit Use 

2. Transportation Allowances 

3. Eliminate Employee Parking Subsidies 

4. Charge for Drive-Alone Parking 

HI. Work Schedule Changes 

A. Telecommuting 

1. Home 

2. Satellite Work Center 

3. Neighborhood Work Center 

Transportation Control Measure (TCM) Typology 
B. Flextime 

1. Daily Start/End Time 

2. Number of Hours Worked 

a. Per Day 

b. PerWeek 

c. Per Pay Period 

C. Compressed Work Week 

1. 4 Day Week, 10 Hour Work Day 

2. 5/4-9 Plan (80 Hours in 9 Days) 

D. Staggered Work Hours 

IV. Area-wide Rideshare Incentives 

A. Areawide Commute Management Organizations (Third Party Brokerage) 

1. Carpool Matching Programs 

2. Vanpool Programs 

3. Shared Ride Taxi 

4. Guaranteed Ride Home 

B. Transportation Management Associations (TMAs) 

1. Operation of Ridesharing and Other Transportation Management 

Programs 

2. Education 

3. Informational Materials 

4. Advocacy 

5. Transportation Service Coordinators 

6. Employee Surveys 

7. Organization 

a. Independent, Non-Profit Corporations 

b. Existing Business Organizations 

C. Tax Incentives and Subsidy Programs 

1. State/ Local Tax Exemptions for Vanpool or Transit Subsidies 

2. Exemption of Ridesharing Vehicles from "Common Carrier" Status 

3. Safety Regulations for Vanpools, Buspools, Subscription Buses 

4. Insurance Coverage 

5. Liability Responsibility 

6. Accelerated Depreciation Allowance for Employer-Provided Vanpools 

and Bicycle Facilities 

7. State/Local Gas Tax Exemptions for Provision of Vanpool Benefits 

V. Improved Public Transit 

A. System/Service Expansion 

1. Fixed Guideway Transit 

2. Fixed Route and Express Bus Services 

3. Circumferential and Local Bus Service 

4. Paratransit Programs 

Transportation Control Measure (TCM) Typology 
B. System/Service Operational Improvements 

1. Feeder Bus Service 

2. Express Bus Service 

3. Bus Route and Schedule Modifications 

4. Improved Transfers 

5. Schedule Coordination 

6. Bus Traffic Signal Preemption 

7. Road Operational Changes 

8. Operations Monitoring 

9. Maintenance Improvements 

10. Park/Ride Service 

11. Subscription Bus Service 

C. Demand/Market Strategies 

1. Employer Offered Incentives 

2. Marketing and Information Programs 

3. Peak/Off-peak Transit Fares 

4. Simplified Fare Collection 

5. Reduced Fares 

6. Monthly Passes 

7. Uniticket Programs 

8. Passenger Amenities 

9. Joint Development Activities 

VI. High Occupancy Vehicle Lanes 

A. Freeways 

1. Exclusive, in a separate right of way 

2. Barrier or buffer-separated 

3. Concurrent-flow (no physical separation) 

4. Contra-flow 

5. Queue bypass 

B. Arterials 

1. Concurrent-flow 

2. Contra-flow 

3. Median 

4. Bus Street 

5. Bus Tunnel 

C. Entrance Ramp Priority 

D. Parking Facilities 

. E. Applicability 

1. Buses 

2. Carpools 

a. 2+ occupants 

b. 3+occupants 

3. Vanpools 

4. Other 

5. Time Periods 

a. Peak Periods 

b. Entire Day 

Transportation Coittrol Measure (TCM) Typology 
VII. Traffic Flow Improvements 

A. Traffic Signalization 

1. Local Intersection Signal Improvements 

2. Interconnected Arterial Signal System 

3. Area Signal System 

4. Equipment or Software Updating 

5. Eliminate Unnecessary Signals and Stop Signs 

B. Traffic Operations 

1. Intersection and Roadway Widening 

2. One-Way Streets 

3. Turn Lane Installation 

4. Turning Movement and Lane Use Restrictions 

5. Reversible Lane System 

6. Strengthen Curb Cut Controls 

C. Enforcement and Management 

1. New Freeway Lane Using Shoulders or Reduced Lane Widths 

2. Incident Management Systems 

3. Freeway Diversion and Advisory Signing 

4. Ramp Metering 

5. Surveillance and Control 

6. Enforcement 

D. Intelligent Vehicle and Highway Systems (TVHS) 

Parking Management 

A. Preferential Parking for High Occupancy Vehicles 

1. Garages and Lots 

2. Metered Spaces 

B. Public Sector Parking Pricing 

1. Alter Rates 

2. Long vs. Short Term Parking 

3. Impose New Prices 

4. Tax the Provision of Free Private Parking 

C. Parking Requirements in Zoning Codes 

1. Revise Maximum and Minimum Requirements 

2. Allow Reductions in Minimum Requirements for Traffic 

Mitigation Actions 

D. On-Street Parking Controls 

1. Curb Parking Restrictions 

2. Residential Parking Controls 

3. Peak Hour Parking Ban and Enforcement 

4. Reduced Legal Parking Spaces in High Congestion Areas 

5. Increase Meter Fees 

6. Increased Enforcement and Towing 

E. Commercial Vehicles 

1. On-Street Loading Zones 

2. Off-Street Loading Areas 

3. Peak Hour On-Street Loading Prohibition 

Transportation Control Measure (TCM) Typology 
F. Control of Parking Supply 

1. limit Construction of New Parking Facilities in Areas Served by Mass 

Transit 

2. Limit Number of On- and Off-Street Parking Spaces in Designated Areas 

3. Use of Zoning and Parking Regulations to limit Capacity 

IX. Park-and-Ride/Fringe Parking 

A. Construct New/Enlarged Dedicated Facilities on Public Property 

B. Use of Direct Ramps to Connect Park-and-Ride Lot with Freeway System 

C. Locate Personal Business Support Services at Park-and-Ride Lots including 

Day-Care Centers, Financial Services, Convenience Stores, and Dry 

Cleaners 

D. Joint Use of Theater, Shopping Center, Church, Stadium Parking Facilities, 

as Available 

E. Parking at all Major Transit Stations 

F. Locate Fringe Parking to Serve Major Highway Facilities/Interchanges Near 

Central Business District 

G. Provide Transit/Shuttle Services to Park and Ride/Fringe Parking 

H. Priority Parking for HOV's at Major Parking Facilities 

I. Provide Bicycle Lockers/Storage at Parking Facilities 

X. Bicycle and Pedestrian Programs 

A. Bicycle Facilities 

1. Bicycle Routes, Lanes, and Paths 

2. Bicycle Plans and Maps 

3. Bicycle Coordinators 

4. Lockers, Racks, and Other Storage Facilities 

5. Showers and Clothing Lockers 

6. Integration with Transit 

7. Ordinances 

8. Education 

9. Media and Promotion 

B. Pedestrian Facilities and Programs 

1. Sidewalks and Walkways 

2. Safe Facilities 

a. Crosswalks 

b. Walk Signals 

c. Median Strips 

d. Speed Ramps 

e. Lighting 

f. Clear Sight Lines 

3. Sidewalk Environment/Furniture 

a. Benches 

b. Street Level Shops 

c. Amenities 

4. Connections with Transit 

5. Education 

Transportation Control Measure (TCM) Typology 
XI. Special Events 

1. Remote Parking with Shuttle Service 

2. Public Transportation 

3. Highway Improvements 

4. Signage, Communication and Public Education/Information 

5. Traffic Flow Improvements 

6. Parking Management 

7. Pedestrian Access/Circulation 

8. Public and Private Coordination Committee 

9. Operations Response Teams 

10. Alternate Travel Schedules 

11. Rescheduling of Truck Travel 

XII. Vehicle Use Limitations/Restrictions 

A. Route Diversion 

1. Auto Restricted Zones 

2. Pedestrian Malls 

3. Traffic Controls 

B. No-Drive Days 

1. Voluntary 

2. Required (e.g., License Plate) 

C. Control of Truck Movements 

1. Designated Truck Routes 

2. Truck Management Strategies 

a. Sign Placement 

b. Variable Message Signs 

c. Speed Restrictions 

d. Additional Lanes 

e. Lane Restrictions 

f. Mobile Safety Inspection Teams 

3. Scheduling of Shipping/Receiving 

4. Peak Period Truck Bans on Freeways or Major Arterials 

5. Freight and Delivery Consolidation 

XIII. Accelerated Retirement of Vehicles 

A. Vehicle Eligibility 

B. Dollar Value of Payment 

C. Program Duration 

1. Length of Buy-Back Period 

2. One Time Program 

3. Sequential Program 

D. Limitations on Number of Vehicles Bought 

1. None 

2. Maximum Number 

E. Retirement vs. Tune Up 

F. Administration 

1. Public Sector 

2. Private Sector 

3. Use of Credits in Emissions Banking and Trading 

Transportation Cotitrol Measure (TCM) Typology 
XIV. Activity Centers 

A. Design Guidelines/Regulations 

1. Transit 

2. Carpooling and Vanpooling 

3. Pedestrian 

4. Bicycling 

8. Parking Regulations and Standards 

C. Mixed Use Development Ordinances and Zones 

D. Site Plan Review Ordinances 

XV. Extended Vehicle Idling 

A. Controls on Drive-Through Facilities 

1. New Facilities 

2. Existing Facilities 

B. Limitations on Idling of Heavy-Duty Vehicles 

1. Trucks 

2. Buses 

3. Locomotives and Other Mobile Sources 

C. Vehicle Modifications 

XVI. Extreme Low-Temperature Cold Starts 

A. Vehicle Modifications 

1. Block Heaters 

2. Intake Manifold Heaters 

3. Monolithic Catalysts 

4. Start or Warm-up Catalysts 

5. Multipoint Fuel Injection Systems 

B. Parking Facility Electrical Outlets 

1. Public Facilities 

2. Private Employers 

C. Transit Use Incentives 

D. No-Drive Days 

E. Vehicle Fleet Operations 

Transportation Control Measure (TCM) Typology 
Summary
Summary 

Purpose 

This report contains the transportation control measure information documents prepared under Section 108(f) of the Qean Air Act. Each of the sixteen measures identified 

in Table 1 is described in terms of its objectives, variations in the ways it may be applied, 

representative examples of actual usage, expected transportation and emissions impacts, 

other potentially important considerations, and a set of implementation guidelines that 

can be followed by state, regional, and local agencies. 

The term "transportation control measure" or TCM encompasses elements of both 

"transportation system management" (TSM) and "transportation demand management" 

(TDM). Transportation system management strategies generally refer to the use of low 

capital intensive transportation improvements to increase the efficiency of transportation facilities and services. These can include carpool and vanpool programs, 

parking management, traffic flow improvements, high occupancy vehicle lanes, and 

park-and-ride lots. The TSM term also is applied to techniques used to reduce the 

demand for travel within an area. Transportation demand management generally refers 

to policies, programs, and actions that are directed towards increasing the use of high 

occupancy vehicles (transit, carpooling, and vanpooling) and the use of bicycling and 

walking. TDM also can include activities that encourage commuting outside the 

congested peak period, and that encourage telecommuting as an alternative to driving. 

In practice, there is considerable overlap among these three concepts and the terms 

TCM, TSM, and TDM often are used interchangeably. 

The Clean Air Act Amendments of 1990 were strongly influenced by a recognition that 

mobile sources are major contributions to air quality problems in nonattainment areas. 

The substantial reductions in tailpipe emissions achieved during the 1970s and 1980s, 

largely through catalytic converters and improvements in fuel efficiency, were rendered 

less effective in their net impact by increases in vehicle trips and vehicle miles traveled 

(VMT). Changes in demographics and employment patterns during the 70s and 80s 

have resulted to increases in vehicle ownership and VMT that are higher than growth 

rates in population. As a result, net emissions reductions from mobile sources generally 

have been lower than originally anticipated despite significant technological advances. 

This report provides basic information on transportation control measures for local 

elected officials, private employers and other public and private sector decision-makers 

who will need to assess the applicability of different strategies for solving the mobile 

source emission problem in their area. These information documents also provide 

Summary 
1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

Table 1. Section 108(f) Transportation Control Measure 

Information Documents 

. Trip Reduction Ordinances 

. Employer-Based Transportation Management Programs 

. Work Schedule Changes 

. Area-wide Rideshare Incentives 

. Improved Public Transit 

. High Occupancy Vehicle Lanes 

. Traffic Flow Improvements 

. Parking Management 

. Park-and-Ride/Fringe Parking 

. Bicycle and Pedestrian Measures 

. Special Events 

. Vehicle Use limitations/Restrictions 

. Accelerated Retirement of Vehicles 

. Activity Centers 

. Extended Vehicle Idling 

. Extreme Low-Temperature Cold Starts 

Summary 
information to non-transportation professionals who wish to gain a greater understanding of the potential impacts of TCM strategies. 

The report begins with a general discussion of the interrelationships between transportation and air quality, providing basic background information that is important in 

understanding the manner in which transportation activities can effect emissions. For 

the person who already has an extensive background in transportation air quality, this 

chapter may not be necessary reading. For the person who is relatively new to the field, 

however, this chapter provides background that is not contained in the subsequent individual TCM chapters. 

This summary consists of two parts. This first part summarizes important transportation related provisions of the 1990 amendments to the Clean Air Act, and synthesizes 

the extensive national experience in implementing TCM type programs. The second 

section provides a brief introduction to each of the Section 108(f) transportation control 

measures, including examples, key issues, and implementation considerations. 

Transportation Provisions of the 1990 Clean Air Act 

The 1990 amendments to the Clean Air Act add significantly to the potential importance 

of transportation measures both as elements of a state implementation plan and as 

potential contingency measures. In reviewing these TCM information documents and 

assessing the potential implementation of TCM programs, it is important to have a 

sound understanding of both the many transportation-related requirements now contained in the Clean Air Act and the air quality-related provisions of the Intermodal 

Surface Transportation Efficiency Act of 1991. The following is a very brief summary of 

some of the more important of these provisions. Amplification and important details, 

however, are not provided in the interest of conciseness. A careful reading of the relevant sections of the Clean Air Act and the Intermodal Surface Transportation Efficiency 

Act is recommended. 

• An implementation plan is to include enforceable control measures, including time 

schedules and compliance procedures (Section 110(a)(2)). These control measures 

can include economic incentives. 

• Plans should provide for the implementation of all reasonably available control 

measures as expeditiously as practical (Section 172(c». 

• Sixteen categories of transportation control measures are identified (Section 108(f)). 

Severe and extreme ozone areas must adopt specific and enforceable transportation 

control strategies as necessary to demonstrate attainment (Section 182(d)(l)(A». A 

parallel requirement exists for serious carbon monoxide nonattainment areas. (Section 187(b)(2)). 

Summary 
• Reasonable further progress is required in the achievement of air quality deadlines. 

Specifically, annual incremental reductions in emissions as may reasonably be required for ensuring attainment of the standard by the applicable date must be demonstrated (Section 171(1)). 

• Ozone nonattainment areas classified as moderate and above must submit implementation plan revisions that demonstrate a 15 percent reduction in VOC emissions 

by November 15,1996 (Section 182(b)(D). 

• Severe and above ozone areas must utilize transportation strategies to offset the 

growth in emissions due to growth in vehicle miles of travel and vehicle trips (Sec­ tion 182(d)(l)(A)). 

•• Employers with 100 or more employees in severe ozone nonattainment areas are 

required to implement trip reduction programs designed to reduce commute-related 

VMT and vehicle trips by employees sufficiently that the average vehicle occupan­ cy of employee work trips is at least 25 percent above the area average (Section 

182(d)(O(B)). 

• Nonattainment areas that fail to demonstrate compliance or to meet a milestone must 

implement additional control measures from an approved contingency plan. These 

additional measures can include transportation control measures, or economic in­ centives implemented in conjunction with transportation control measures (Section 

182(g)). 

• Serious CO nonattainment areas failing to meet a milestone are required to implement a transportation control program (Section 187(d)). 

• Serious ozone nonattainment areas are to conduct a monitoring program to demon­ strate whether current aggregate vehicle mileage, vehicle emissions, and congestion 

levels are consistent with those assumed for the area's demonstration of attainment 

(Section 182(c)(5)). Where these criteria are found to be in exceedance, a plan re­ vision must be developed that contains transportation control measures drawn from 

but not limited to the Section 108(f) list. 

In summary, transportation control measures must be systematically considered and 

evaluated in the development of implementation plan revisions. These TCM in­ formation documents provide a starting point for these evaluations. Final decisions, though, should be based on the results of local consultation and a determination of what 

is reasonably available, effective, and feasible within the context of an area's transpor­ tation system and the ongoing transportation planning/programming process. 

The Interntodal Surface Transportation Efficiency Act of 1991 (ISTEA) represents 

landmark transportation legislation with potentially far reaching implications for 

helping to achieve the objectives of the Clean Air Act. The Act provides significantly 

increased funding flexibility with respect to how monies can be used for highway, 

transit, and other transportation improvements. A $6 billion Congestion Mitigation and 

Air Quality Improvement Program is created to help implement projects and programs 

Summary 
that will contribute to achieving attainment of the National Ambient Air Quality 

Standards. Eligible projects include Clean Air Act Section 108(0 transportation control 

measures and projects contained in a State Implementation Plan (SIP). Urbanized areas 

over 200,000 population are designated as Transportation Management Areas. Each 

such area is to have a congestion management system that provides for "use of travel 

demand reduction and operational management strategies." The long-range transportation plan for metropolitan areas which are nonattairunent for either ozone or carbon 

monoxide is to be coordinated with the process for developing transportation control 

measures for the Clean Air Act's State Implementation Plan (SIP). 

The Intermodal Surface Transportation Efficiency Act requires coordination between the 

transportation and air quality planning processes, with flexible funding being provided 

to help states and urban areas develop and implement the transportation portions of a 

State Implementation Plan. 

TCM Implementation Experience 

There is extensive experience throughout the country in planning, designing, and 

implementing the kinds of transportation control measures identified in Section 108(f) 

and listed in Table 1. The following paragraphs synthesize this experience into a series 

of overall conclusions regarding the status of transportation control measures. 

The majority of TCMs, but not all, are being routinely implemented across the country 

for a wide variety of objectives, many as part of corridor and regional congestion management plans. These kinds of measures should not be considered as being either controversial or even innovative, but as being feasible and routinely available. 

The implementation of TCMs most often requires a cooperative process involving state, 

regional, and local agencies. In addition, experience has shown the critical role that 

employers have in increasing the effectiveness of an overall TCM program. 

While some TCMs can be planned and implemented over a relatively short time period, 

many require 3 to 5 years to be effectively developed and implemented. Others such as 

rail transit programs should be considered as long range, in terms of both their planning 

requirements and their expected benefit period. 

Area-wide effectiveness (whether VMT or emissions) is critically dependent upon the 

size of the market segment affected. Many TCMs may be directed only at peak period 

or work trips, or to a particular geographic area. Such measures may be highly effective 

within their target market, but have only a limited impact when expressed in overall 

regional terms. Work trips, for example, typically constitute only about 30 percent of 

total travel. However, work trips are the most amenable to control since they constitute 

the most regular set of trips. In addition, employers can exert considerable influence 

over work trip modes. The peak periods also represent the highest concentration of 

Summary 
mobile source emissions and therefore remain an important control target. Additional 

benefits accrue to the region because work trips taken by alternative modes result in 

vehicles being left at home (or in park-and-ride lots) where they are unavailable for midday trips. Furthermore, reductions in peak period trips have added benefits in eliminating congestion-related emissions. 

In many nonattainment areas, analyses have shown that additional stationary, area, and 

non-TCM mobile sources will not be sufficient to achieve attainment of the air quality 

standards within the legislatively mandated time schedules. In these cases, it is not a 

question of whether or not to use TCMs, but what TCMs are needed in addition to these 

other measures. 

TCMs can be thought of in three broad categories: voluntary or incentives, regulatory, 

and market based (or pricing). Ideally, a TCM program should contain incentives as 

well as disincentives, and elements of all three categories. Programs consisting only of 

voluntary incentives consistently have been shown to have lower levels of effectiveness 

than when combined with mandatory requirements and pricing measures. 

Section 182(g)(4) of the new Clean Air Act discusses economic incentive programs and 

states that such programs may include emission fees along with incentives and disincentives to reduce vehicle emissions and vehicle miles of travel. Pricing incentives 

include employer subsidized transit passes and provision of various ridesharing 

services. Other possible employer-based pricing strategies include elimination of free or 

low cost parking for employees, or the provision of a transportation benefit that an 

employee can choose to use for parking, ridesharing, or transit. These Clean Air Act 

provisions are supported by the Intermodal Surface Transportation Efficiency Act of 

1991 which creates a $25 million per year Congestion Pricing Pilot Program. 

The potential transportation impacts of TCMs include changes in vehicle miles of travel, 

the number of trips, vehicle speed, the time of day in which a trip occurs, the destination 

of auto trips, and even the number and type of automobiles which a household chooses 

to own. For example, trip reductions in the range of 15 to 20 percent as result of 

employer-based transportation management programs are not uncommon. The impacts 

of TCM measures and programs are sufficiently large to consider worthwhile and worth 

the effort. 

VMT should not be relied upon exclusively, or even primarily, as a transportation proxy 

for emissions reductions. It is important that changes in vehicle trips and operating 

speed also be examined. Analyses have shown that cold start and the various evaporative emissions are more significant than previously thought, and need to be explicitly 

considered in a transportation emissions analysis. An objective, therefore, should be to 

reduce vehicle trips, rather than just to reduce VMT. 

The non-air quality benefits of TCMs need to be explicitly recognized as part of an air 

quality analysis. These include reduced congestion, improved safety, reduced travel 

time and cost, and the reduced need for new highway construction. Implementation 

decisions in both the public and private sectors are based on a consideration of all 

potentially relevant issues, rather than just a single factor such as air quality. When 

Summary 
properly calculated, the vast majority of TCMs have been shown to have benefit/cost 

ratios greater than one, and frequently as great as ten or higher. Expressed in terms of 

cost/effectiveness, this implies a negative cost/ effectiveness ratio since the value of the 

non-air quality benefits will exceed program costs. 

Developing effective mechanisms for administering, maintaining, and enforcing TCMs is 

a critical element of long-term success. Many programs have enjoyed a short-run 

effectiveness, only to see their impacts erode after two or three years. Certain programs 

have proven difficult to enforce, thereby inviting a high level of violations and generally 

leading eventually to abandonment. Developing these mechanisms means involving 

those organizations that will be involved in administering, maintaining, or enforcing a 

measure in the planning and design of that measure. It also means that adequate staff 

and funding resources need to be allocated, and a meaningful array of violation penalties needs to be in place. 

Developing a Program of Transportation Control Measures 

There is a need for TCM programs that are carefully designed rather than merely 

representing a collection of individual measures. This design process needs to consider: 

• Issues of equity; 

• Providing area-wide measures such as transportation management associations that 

can reinforce more localized measures such as employer-based trip reduction targets; 

• Enhancing the supply of transit, ridesharing, bicycling, and walking options rather 

than just restricting or discouraging the use of drive alone travel; 

• Incorporating elements of pricing and market-based incentives, with particular 

attention paid to the distribution of public and private travel subsidies; 

• Including marketing, education, and public awareness as well as more traditional 

technical activities; 

• Incorporating longer range, permanent measures as well as short run measures that 

are capable of being quickly implemented and producing immediate impacts but 

which also may be more temporary in character; and 

• Assuring adequate intergovernmental involvement, cooperation and commitment. 

A carefully designed, inter-related program may include 15 to 20 individual measures 

and be three to four times as effective as any of the measures taken individually. 

Summary 
Developing an effective monitoring mechanism also is an important element of good 

program design. Benefits may take several years to develop, and it is necessary to 

monitor the changes in the full array of program impacts over a period of several years. 

Monitoring also provides an invaluable evaluation feedback mechanism that can be 

used to improve the design of both individual measures and overall programs. Experience has demonstrated that many TCMs can be improved by "learning while doing." 

Despite the best intentions, it is extremely difficult to anticipate all possible consequences of an action. A mechanism, therefore, needs to be built into a program's 

administration that allows adjustments and enhancements over time. A cautionary 

note, though, is in order. The style of monitoring mat is being recommended is not one 

that is oriented primarily to promotion, public relations, and marketing. Rather the 

objective is to improve the understanding of program operations and impacts. Expressed in terms of an area-wideridesharing organization, information is wanted on the 

number of trips and vehicle miles of travel eliminated, not just the number of carpool 

matching applications processed. 

A systematic process should be followed to identify, screen, evaluate, and develop an 

implementation program for potential TCMs. This process should include but not be 

limited to the following activities: 

• Defining local baseline travel conditions for both the current inventory year and a 

future target year against which program measures will be designed; 

• Identifying other available and planned transportation infrastructure that will either 

support or serve as a barrier to the development of effective TCMs; 

• Identification of other local, regional, and state objectives that are compatible with 

programs to improve transportation-related air quality; 

• Develop realistic target levels of effectiveness based on the local baseline travel 

conditions; 

• Estimate capital and operating costs, and necessary administrative requirements; 

• Determine the availability of funding and other necessary program resources, 

considering private as well as traditional public mechanisms; and 

• Involve business and other community groups, gradually developing an understanding of all relevant issues and gaining acceptance of the developed program. 

There are variations in the effectiveness of TCMs by urban area, depending upon the 

density and distribution of population and employment, the form of existing highway 

and transit systems, and population/employment demographics. It is difficult, indeed 

dangerous, to apply a single effectiveness number (or even a narrow range) to different 

urban areas. This is true for travel measures such as VMT; it is especially true for estimates of emissions which are in addition highly sensitive to temperature and composition of the vehicle fleet. 

Summary 
It is useful and even necessary, therefore, to quantitatively analyze the effectiveness of 

TCM programs. The standard four stage urban transportation analysis process can 

serve as a base for this analytical capability, but generally needs to be refined and 

extended if it is to be successfully applied for air quality analysis purposes. A variety of 

"sketch planning" analysis approaches also are available, and can be considered as 

feasible alternatives to use of the full and standard UTPS-style analysis systems. EPA is 

preparing separate information on methodologies to analyze changes in travel activity 

due to TCMs. 

TCM Approval Criteria 

Before a program of TCMs can be approved, the program must meet federal State 

Implementation Plan (SIP) submittal requirements. The EPA has prepared a SIP 

Submittal Completeness Checklist (40 CFR, Part 51, Federal Register, February 15,1990, p. 5824), to guide the preparation and review of SIP submittals. Where applicable, TCMs included in a SIP will be subject to these criteria. In addition, at a minimum, the 

SIP must provide evidence of adequate financial and human resources for each TCM, and must describe the process of implementation, enforcement, monitoring and 

maintenance of the program. Note that, depending on the measure, some of these 

criteria may not be applicable. Also, individual states may have additional criteria, such 

as quantifying economic impacts, which must be addressed. In any case, the documen­ tation for a program of TCMs should be discussed with the EPA Regional Office prior to 

formal incorporation into a SIP. 

Summaries of Individual Transportation Control Measures 

The effectiveness of transportation control measures can be enhanced through a con-, sideration of their synergistic effects. In general, an integrated program of TCMs should 

be implemented so as to achieve the full travel and emissions reduction potential of the 

individual strategies. It is important to understand, therefore, that some TCMs are 

mutually supportive, while others are potentially in conflict. For example: 

• Trip redaction ordinances can be significantly enhanced by offering alternatives to 

single-occupant vehicle travel such as improved public transit, bicycle and 

pedestrian improvements, and area-wide ridesharing. 

• Park-and-ride and fringe parking strategies can support the provision of HOV lanes 

and improved public transit. 

Summary 
• Vehicle use limitations/restrictions can be reinforced through parking management 

and strategies to address congestion at major activity centers. 

At the same time, certain strategies may conflict with one another and still other 

strategies may have few, if any, synergbtic or countervailing effects. 

Trip Reduction Ordinances 

Definition: Requirements designed to encourage use of alternative transportation 

modes, rather than single-occupant vehicles. Enacted through local or regional 

government regulations or ordinances, such as zoning ordinances or building codes. Can establish performance goals or limitations on volume of trips generated from 

specific employment sites or developments. 

Examples: Policies to encourage provision of commute alternatives information and 

incentives at workplace; trip reduction requirements through negotiations over re­ zoning; trip reduction activities as quid pro quo for reductions in parking space require­ ments; imposition of impact fees to fund transportation improvements; incorporation of 

trip reduction measures as condition of approval of new development; requirements 

that development or employers over a specified size develop and implement demand 

management programs. 

Have been in existence, initially in California municipalities, for over a decade. Applications have spread in recent years. Currently, at least 60 TROs (in various forms) 

exist nationwide. 

Key Issues: Allows for systematic management of travel behavior, particularly in areas 

experiencing new development; provides a tool to local governments to plan and control 

for effects of new development on transportation infrastructure; latitude for TRO design 

allows for wide range of options and applications; requirements can be voluntary 

and/or mandatory; can be designed to target specific trip types. 

Considerations: May be viewed as anti-growth or as imposing added costs to devel­ opment; emphasis should be on encouragement of socially beneficial travel choices 

rather than direct control of travel behavior. 

Employer-Based Transportation Management Programs 

Definition: Various programs implemented by employers to manage the commute and 

travel behavior of employees, with the objective of reducing the number of single 

occupant automobiles used for commuting. 

Examples: Alternative travel modes (such as vanpooling and carpooling, subscription 

buses, bicycling, walking, shuttle services, guaranteed rides home), alternative work 

Summary % 10 
schedules, financial incentives and disincentives (including transit pass subsidies, subsidized vanpools, transportation allowances), and on-site support (such as on-site sale of 

transit passes, transportation coordinators, information dissemination). 

Have been used primarily by large employers, those having more than 100 employees at 

a single worksite. Examples include the 3M Company in Minneapolis — St. Paul; the 

Nuclear Regulatory Commission in Montgomery County, Maryland; and public, 

private, and non-profit employers in urban areas such as Seattle, Los Angeles, San 

Francisco, Washington, Boston, and Hartford. Some programs began as early as the 

1920's. Many of the newer programs began with the energy crises of the mid- and late1970's. Congestion management currently is an important motivation. 

Key Issues: Programs can consist of both voluntary and mandatory measures; generally, a "package" of various complementary measures produces greatest impacts. 

Considerations: Must obtain cooperation of majority of employers within target area in 

order to effectively reduce area-wide commute trips; most effective programs result 

from motivation of employer to reduce demand for limited parking or to assure accessibility of employees to workplace. 

Work Schedule Changes 

Definition: Changes in work schedule to provide greater flexibility in work schedule 

and reduce volume of commute travel during peak periods. This, in turn, can facilitate 

and encourage the development of ridesharing arrangements, off-peak commuting, 

and/or reductions in total commute trips. 

Examples: Telecommuting, flexible work hours ("flextime"), compressed work weeks, 

staggered work hours. 

There is much current interest in telecommuting, with a number of pilot and demonstration programs existing in the western portion of the country. Examples include the 

Puget Sound (Washington State) Telecommuting Demonstration Project, the State of 

California Telecommuting Project, and the Los Angeles County program in which 1,700 

employees telecommute at least one day a week. 

Flexible work schedules are in widespread use by many employers, both large and 

small, on a national scale. An example of a city wide program is the San Francisco 

California Flextime Demonstration Project. Many federal employees participate in 

compressed work week programs. 

Key Issues: Can support ridesharing activities by providing greater flexibility in 

coordination of arrival and departure schedules by potential pool partners. Fears that 

reductions in work trip VMT would be offset by increased non-work travel generally 

have not been realized. 

Summary 11 
Considerations: A number of important organizational and personnel issues need to be 

considered and work schedule changes may not be applicable to employers involved in 

certain businesses or industries whose production processes require adherence to strict 

schedules. These programs, however, should be acceptable to most employers and employees if carefully developed. 

Area-Wide Rideshare Incentives 

Definition: Promotion and assistance through state, regional, or local efforts aimed at 

encouraging commuters to use alternatives to driving alone to work and encouraging 

employers to provide in-house programs that promote ridesharing, transit, bicycling, 

and walking among employees. 

Examples: Three broad categories of area-wide rideshare incentive programs are: 

1) area-wide commute management organizations (or third-party brokerages), 2) transportation management associations, and 3) state and local tax incentive and subsidy programs. Services provided include: computerized carpool matching; vanpool matching; 

provision of vanpool vehicles; marketing of ridesharing; technical assistance to employers; tax credits; and financial subsidies. 

Many examples of rideshare incentives and promotional programs exist on a national 

scale. Promotion and computerized matching is often provided by commute management organizations. Examples include Sacramento Rideshare (Caltrans), Montgomery 

County (Maryland) Rideshare and CARAVAN for Commuters (Boston, MA). Subsidy 

of vanpool participation and/or vehicle costs have been in effect in various locations 

nationally. California also provides tax incentives to employers and employees who 

participate in rideshare programs. Numerous transportation management associations 

have been established throughout the country, including at least 50 within the State of 

California. 

Key Issues: Can effectively facilitate employer/developer-based transportation 

management programs; recent studies have identified availability of HOV priority 

treatment and guaranteed ride home programs as significant incentives to encourage 

ridesharing. 

Considerations: Area-wide commute management programs, transportation management associations, and tax incentives support employer-based transportation management programs. They are particularly effective in enhancing the efforts of smaller 

and mid-size employers. In evaluating the impacts of area-wide programs, though, care 

needs to be taken not to double count the effectiveness of these programs with the 

benefits credited to employer programs. In addition, the roles and responsibilities of 

various public, non-profit, and for-profit organizations involved in promoting ridesharing and other travel alternatives within a region need to be carefully delineated so 

that the various efforts are not perceived as either duplicative or conflicting by employers and individuals. 

Summary 12 
Improved Public Transit 

Definition: Implementation of new or expanded public transit services relevant to all 

transit modes such as paratransit, buses, rapid transit, and commuter rail. 

Examples: System or service expansion (new or extended routes, higher service fre­ quencies); system /service operational improvements (route and schedule modifications, improved transfer procedures, schedule coordination, operations monitoring, improved 

maintenance practices), and strategies to enhance market demand (marketing programs, reduced fares, employer provided transit fringe benefit, monthly pass programs, pas­ senger amenities, parking). 

Transit services are available in virtually every urban and many non-urban areas in the 

U.S. Examples of improvements range from low-cost measures such as schedule 

coordination to more capital intensive programs such as provision of new or extended 

services. 

Key Issues: Serves as the primary alternative mode to automobile use in most urbanized areas; must successfully compete with automobile use in terms of cost and/or 

travel times in order to attract new ridership. 

Considerations: Effectiveness is closely tied to land use patterns in service area and 

extent to which transit services have adapted to changes in local, residential, em­ ployment, and travel patterns over time. Expansion of services can have high capital 

and/or labor costs; low cost improvements are feasible through operational changes. Because transit services seldom break even financially, a stable source of funding 

support is essential. In evaluating the air quality impacts of improved transit services, it 

is necessary to consider the travel mode that otherwise would be used (e.g., riders on a 

new rail transit line may have previously ridden a transit bus) and the mode of access to 

transit (e.g., use of a car to drive to a park-and-ride lot may eliminate vehicle miles of 

travel but still incurs the vehicle start-up or cold start emissions). 

High Occupancy Vehicle Lanes 

Definition: Travel lanes designated for use by high occupancy vehicles (HOV) such as 

carpools, vanpools, and transit vehicles. 

Examples: HOV lane in a separate highway right-of-way or within freeway right-ofway; contra-flow lane located in "off-peak" direction. 

Widespread applications on freeways and arterials in many larger urban areas with 

severe peak period congestion. In 1989, there were 38 freeway HOV facilities operating 

in 18 U.S. metropolitan areas. New York City has implemented an extensive bus lane 

program throughout the city on arterial streets. 

Summary 13 
Key Issues: HOV facilities are mutually supportive with many other TCM programs 

(Area-wide ridesharing, employer-based transportation management programs, trip 

reduction ordinances, etc.) by facilitating higher average travel speeds and travel time 

reliability for HOVs in comparison to travel via private automobile. 

Considerations: HOV lanes need to operate at higher speeds relative to normal mixed 

flow highway lanes in order to serve as a desirable alternative. Freeflow highway conditions are a disincentive to HOV use. Enforcement of HOV restrictions is critical to 

maintaining integrity of facilities. Support facilities such as park-and-ride lots, employer 

rideshare programs, and downtown preferential parking are desirable components of 

program. Separate HOV facilities should be developed so as to form an overall regional 

system. 

Traffic Flow Improvements 

Definition: A range of actions that enhance the person-carrying capacity and efficiency 

of the roadway system, without adding significantly to the width of the roadway. 

Examples: Improved traffic signalization (such as changes to signal timing, signal 

coordination, removal of signals); improved traffic operations (such as turn restrictions, 

median strips, channelized roadways/intersections, roadway /intersection widening or 

reconstruction) and, enforcement and management improvements (such as increased 

police surveillance, incident management, and ramp metering). 

Traffic flow improvements are widely applied by both state and municipal transportation agencies, primarily to reduce congestion and improve travel times at specific 

locations. Examples of coordinated, area-wide programs include the Back Bay (Boston, 

Massachusetts) Traffic Operations and Management Study and the Sacramento, California Signal System Improvement Program. 

Key Issues: Reduced congestion and improved vehicle travel speeds result in reduced 

emission rates per vehicle mile of operation. Reduced delay at intersections can effectively control CO "hotspot" conditions. With ramp metering, it is important to consider 

the emissions which may occur during excessive queuing and under high levels of 

acceleration when a vehicle enters the freeway traffic stream. 

Considerations: Traffic engineering measures do not necessarily reduce VMT, although 

they may cause a shift of VMT from specific areas or corridors to other locations. 

Measures which substantially reduce delay and improve travel speeds may attract 

higher traffic volumes to the affected corridor and/or roadways, thereby offsetting 

benefits of the measures. 

Summary 14 
Parking Management 

Definition: The management of parking supply and demand; including public and 

private parking facilities, and both on- and off-street parking. Strategies can include 

pricing, zoning actions, and usage. 

Examples: Preferential parking pricing programs favoring HOVs, provision of 

preferential or reserved spaces for HOVs; fee structures which discourage long-term 

(commuter) parking; increased parking fees or taxes; zoning regulations controlling 

magnitude of parking in conjunction with new development; limitations on the development of new public or private parking spaces. 

Preferential parking for HOVs has been offered in numerous cities at municipally 

controlled parking facilities. Parking pricing strategies have been applied, on a limited 

scale, at selected parking facilities. Availability of parking spaces is generally regulated 

by most municipalities in local zoning codes and rates have been adjusted, in various 

cities to discourage single-occupant vehicle use. Controls on parking supplied have 

been applied in Boston, Portland, Oregon, and San Francisco. 

Key Issues: Cost and availability of parking is a key variable in determining travel 

mode to work. Increases in parking costs and/or decreases in availability produce shifts 

to alternative modes. Individual municipalities may have limited ability to influence 

parking supply and prices at privately-operated parking facilities. 

Considerations: Parking management strategies are most effective when implemented 

in dense central business districts or activity centers that have limited available parking. 

Patterns of dispersed development diminish the effectiveness of parking strategies. In 

addition, if there is an excess of parking supply, then implementing parking actions that 

only affect a portion of the spaces may simply result in a reallocation of where people 

choose to park rather than in a change of mode of travel. 

Implementation of parking management strategies is most successful in areas having 

very high land values and a strong economic development climate that result in disincentives for devoting land to parking. Relatively good transit access that provides an 

alternative to automobile usage also is important. 

Park and Ride/Fringe Parking 

Definition: Parking facilities designed to facilitate transfer to transit services, carpooling, and vanpooling. 

Examples: Automobile and bicycle parking at transit locations (commuter rail, rapid 

transit, bus stops) remote from the downtown core or major activity centers; remote or 

fringe parking facilities at highway interchanges or in heavily travelled commuting 

corridors. 

Summary 15 
Most large transit systems provide parking in conjunction with transit services. Parkand-ride facilities can be informally designated or formally established by state or local 

transportation agencies. Examples include the California Department of Transportation 

(Caltrans) and the Connecticut Department of Transportation (ConnDOT) Park-andRide Programs. 

Key Issues: Can be significant incentive in formation of rideshare arrangements and use 

of transit services. Provides means of intercepting vehicles before they enter congested 

or core areas. Success of a given site is closely tied to the level of transit and ridesharing 

service provided and the location of the site in relation to travel corridors and final trip 

destinations. 

Considerations: Planning of facilities should account for local traffic conditions in 

vicinity of potential parking sites to avoid exacerbation of local traffic or air quality 

problems, particularly as result of increased cold starts in vicinity of parking site. Lots 

should be developed with consideration given to pedestrian and bicycle access, and the 

availability of personal support systems such as banking, convenience stores and daycare. 

Bicycle and Pedestrian Programs 

Definition: Measures to encourage bicycle and pedestrian travel as viable alternative 

transportation modes to the private automobile. 

Examples: Bicycle paths; secure bicycle parking/storage facilities; increased enforcement of traffic regulations relevant to pedestrian and bicycle movements; enhancement of pedestrian crossing signalization or pavement markings; bicycle commute 

education programs; removal of barriers restricting bicycle and pedestrian movements; 

roadway and site design compatible with pedestrian and bicycle accessibility. 

Several cities have incorporated bicycling programs into their transportation plans. 

Many successful bicycling programs have been implemented. Examples of citywide 

programs include Tucson, AZ, Seattle, WA, Madison, WI, Washington, D.C., and 

Boulder, CO. Many examples of specific facilities such as bike paths and storage 

facilities nationally. Limited examples of comprehensive pedestrian programs although 

appropriate design to accommodate pedestrian movement is standard in most urban 

design criteria. 

Key Issues: Non-motorized transportation provides non-polluting mobility; well-suited 

for short distance trips and light loads. Low user costs compared to other modes. 

Considerations: Extent of participation is sensitive to trip length, topographical and 

climatic factors, as well as demographics of population. Concern over personal safety 

due to conflicts with motorized vehicles and security of bicycle while parked can be 

major disincentives. 

Summary 16 
Special Events 

Definition: Special plans to manage travel demand in effect during special events, 

defined as destinations for a large number of vehicle trips which occur on a one-time, 

infrequent, or scheduled basis (such as athletic events, festivals, fairs, political rallies, 

and major entertainment performances). 

Examples: Parking management; remote parking; signage to direct motorists to appropriate routes and destinations; highway improvements; public information and 

communications systems; enhanced public transportation and shuttle services; increased 

police presence. 

These measures are an important consideration for any event likely to draw unusually 

large crowds which exceed normal capacity of existing transportation systems. Specific 

examples include mega-events such as the Knoxville, Tennessee World's Fair, Expo 86 in 

Vancouver, British Columbia, and the 1984 Summer Olympics in Los Angeles; roadway 

reconstruction projects such as Boston's Southeast Expressway; and, neighborhood 

street fairs and parades. 

Key Issues: Success of measures is highly dependent upon advance planning and 

anticipation of transportation needs and problems. Due to short-term nature of demand, emphasis should be on transportation systems management (TSM) approaches, 

rather than capital-intensive strategies. 

Considerations: Uncertainty in predictions of attendance at event can complicate 

planning. Also, uncertainty involved in anticipating willingness of attendees to utilize 

alternative transportation services and systems management measures. 

Vehicle Use Limitations/Restrictions 

Definition: Techniques to Limit or restrict the use of certain types of vehicles in a given 

geographic area or specified time period (such as peak travel periods). 

Examples: Route diversions (such as auto restricted zones or ARZs, pedestrian malls, 

and residential traffic controls), no-drive days, and controls on truck movements (such 

as designation of truck routes, scheduling of truck operations). 

Auto restricted zones and pedestrian malls have been implemented in many downtown 

areas in U.S. and Europe. No-drive day programs have been implemented in Denver, 

Colorado and Phoenix, Arizona. Cities have traditionally regulated the movement of 

trucks on local streets by restricting trucks from certain areas of central business district 

during peak hours, restricting loading zones, and scheduling deliveries. Proposals now 

are being made for more aggressive truck management strategies and for broader 

limitations on truck movements during peak periods. 

Summary 17 
Key Issues: The development of auto restricted zone programs requires coordination 

with area businesses, careful consideration of the area's economic strengths and weaknesses, and development of alternative means of providing access to and circulation 

within the area. No-drive day programs should be integrated with other programs 

which provide viable alternative transportation on affected days; no-drive day programs 

require significant marketing efforts and cooperation of local media. The control of 

truck movements involves legal considerations, as well as the cooperation and support 

of the trucking industry. 

Considerations: All programs should be designed to accommodate needs of commercial interests which would require accessibility by customers/clients for goods delivery. 

Auto restricted zones have been successful where there already is a stable base of economic activity, but may not be sufficient by themselves to rejuvenate an economically 

decaying area. In U.S., no-drive days are currently all voluntary. The implementation 

of controls on truck movements needs to consider the time periods and routes actually 

being used for current movements, the direct costs to businesses of the controls, and the 

indirect costs to the economy of different patterns of truck movements. 

Accelerated Retirement of Vehicles 

Definition: Offer to purchase older vehicles having high emission rates in order to 

remove these vehicles from the active vehicle fleet. 

Examples: Unocal Corp. operated a program of this type in the Los Angeles metropolitan area during the summer of 1990. The South Coast Recycled Auto Project 

(SCRAP) offered $700 for pre-1971 model year cars that met a set of requirements to 

ensure that active vehicles were being removed. Eight thousand, three hundred and 

fifty autos were bought and crushed. Policy decisions include definition of the target 

vehicle population to be removed, the dollar amount of the payment to be made, and 

the duration of the program. 

Key Issues: Program design variables include the age and eligibility of vehicles, the 

duration of the buy-back period, and whether the program is a one-time effort or 

repeated periodically. 

Considerations: The average remaining life of the removed vehicle affects the number 

of years over which emission reductions can be credited. Assumptions regarding the 

age of replacement vehicles and the additional mileage driven by either replacement or 

other vehicles affects the net magnitude of the estimated emissions to be eliminated. 

Activity Centers 

Definition: Urban design and transportation measures designed to reduce automobile 

trips and to promote non-automobile travel associated with the use of cohesive activity 

Summary 18 
centers such as office parks, shopping centers, mixed-use developments, and other 

centers of vehicle activity. 

Examples: Transit friendly design guidelines and ordinances; vanpool and carpool 

considerations; pedestrian and bicycle design considerations; parking standards and 

regulation; mixed-use development ordinances and zones; site plan review ordinances. 

A number of developments planned and built in the U.S. since 1930 illustrate examples 

of design guidelines intended to reduce auto dependency. Sacramento County, California, is developing comprehensive "Transit-Oriented Development" guidelines as part 

of that area's comprehensive plan. 

Key Issues: By incorporating opportunities for alternative travel modes such as transit, 

HOVs, bicycles, and walking into overall design of new development, the desirability of 

these alternative modes is enhanced. Higher density of development makes use of 

HOVs and transit more feasible. Mix of appropriate land uses within a development can 

reduce the need for certain types of trips if need can be met in immediate vicinity of 

residence or place of work. 

Considerations: Rate at which measures can be implemented is directly related to rate 

of new development. Generally considered a long-term strategy. Can have administrative implications for public sector due to requirements for implementing and 

enforcing urban design codes and providing services/infrastructure for higher density 

development. Economic trade-offs for private sector involve potentially higher development costs and correspondingly increased market value and revenues. 

Extended Vehicle Idling 

Definition: Measures to reduce amount of time which vehicles spend in idle mode as 

part of their overall operation. 

Examples: Controls on construction and operation of drive-thru facilities such as banks 

and fast food restaurants; controls on extended vehicle idling during layover time, 

particularly of diesel engines used by transit vehicles and delivery trucks. 

Programs to limit heavy truck idling are being considered in California. Sacramento 

Metropolitan Area regulates the number and design of new drive-up window facilities. 

Key Issues: Implementation of controls on vehicle operations should be at regional or 

state level, rather than local. Restrictions on drive-thru facilities are local responsibility, 

enforced through zoning code. Public education regarding idling emissions and their 

control can be further option. 

Considerations: The trade-off between idling emissions and hot start/hot soak emissions generated by vehicles which have been shut off and restarted; dependent upon 

vehicle age and type. 

Summary 19 
Extreme Low-Temperature Cold Starts 

Definition: Actions that can be taken by states, and local areas over and above the new 

Federal cold temperature carbon monoxide standard and that are applicable under 

extremely cold conditions; e.g., temperatures in the range of 0 degrees F to -20 degrees F, 

or even colder. These measures normally are directed at reducing vehicle start-up 

emissions during these extremely cold temperature episodes. Other possibilities include 

incentives that would entirely eliminate the need for low occupancy vehicle use during 

these periods, thereby eliminating the entire cold start phase altogether. 

Examples: Mechanical devices to control CO emissions during cold starts include block 

heaters, intake manifold heaters, monolithic catalysts, and multipoint fuel injection 

systems. Other options include traditional transportation control measures to reduce 

auto use. 

Experience is limited primarily to State of Alaska. A voluntary program to encourage 

use of block heaters at the workplace was initiated by the Fairbanks North Star Borough. 

Key Issues: Retrofit of vehicles can typically cost $100-300 per vehicle. Also can involve 

cost to operators of parking facilities to install and provide electrical power to electrical 

outlets to operate block heaters. 

Considerations: Technical feasibility of measures has been demonstrated for cold 

climates but practical applications have been limited. 

Summary 20