Impact of Exempt Vehicles 

on Managed Lanes

Publication No. FHWA-HOP-14-006 

January 15, 2014
Notice

This document is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information 

exchange. The U.S. Government assumes no liability for the use of the information contained in this document.

The U.S. Government does not endorse products or manufacturers. Trademarks or manufacturers’ names appear in this report 

only because they are considered essential to the objective of the document.

Quality Assurance Statement

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IMPACT OF EXEMPT VEHICLES ON 

MANAGED LANES 2014
1. Report No.

 FHWA-HOP-14-006

2. Government Accession No. 3. Recipient’s Catalog No.

4. Title and Subtitle

 Impact of Exempt Vehicles on Managed Lanes

5. Report Date

 January 15, 2014

6. Performing Organization

 Code HOTM

 7. Author(s)

 Katherine F. Turnbull, Ph.D.

8. Performing Organization

 Report No.

9. Performing Organization Name and Address Prime Contractor:

Texas A&M Transportation Institute Battelle

The Texas A&M University System 505 King Ave.

College Station, Texas 77843-3135 Columbus, Ohio 43201-2693

10. Work Unit No. (TRAIS)

11. Contract or Grant No.

 DTFH61-13-P-00183

12. Sponsoring Agency Name and Address

 Department of Transportation

 Federal Highway Administration, Office of Operations

 1200 New Jersey Ave., SE

 Washington, D.C. 20590

13. Type of Report and Period 

 Covered

 Final Report, March 2014

14. Sponsoring Agency Code

 HOP, HOTM

15. Supplementary Notes

 Contact: Neil C. Spiller, Transportation Specialist, FHWA, Office of Operations, HOTM, 202-366-2188, neil.spiller@dot.gov

16. Abstract

In order to better utilize available capacity in high-occupancy vehicle (HOV) lanes, states are permitted to allow certain qualifying non-HOVs to use HOV lanes. In general, states may allow motorcycles, public transportation vehicles, high-occupancy 

toll (HOT) vehicles, and low-emission and energy-efficient vehicles to use HOV lanes. For any or all of these types of vehicles, 

the states must establish programs addressing candidacy, enrollment, and management of the lanes. In the case of tolled 

vehicles, dynamic pricing is the primary control that limits the potential to cause congestion in the lanes. In the case of the 

energy-efficient vehicles, the programs typically include decals, licenses, license plates, or stickers, that serve to identify and, in 

some cases, cap the number of allowed to use the lanes vehicles.

Concerns may arise that the number of exempted vehicles may overburden the capacity of the HOV lanes to perform their 

primary function, which is to provide an incentive to form carpools (and thereby reduce the number of cars on the road) and to 

“reward” such an incentive by guaranteeing a mostly delay-free trip. Use by non-HOVs may overburden the HOV lanes, causing the integrity of the HOV lanes to suffer. 

The Moving Ahead for Progress in the 21st Century Act (MAP-21) 2012 now mandates that any HOV facility that allows tolled 

vehicles or any class of qualifying energy-efficient vehicles must annually certify that the subject lanes are “not degraded.” By 

definition, this constitutes that for a 180-day continuous reporting period, the lane(s) operate at greater than 45 mph for 90% of 

the time. (See Section 166, Title 23 of United States Code for the full language.)

This report examines programs in use by states allowing low-emission and energy efficient vehicles to use HOV, HOT, and 

managed lanes without meeting the vehicle-occupancy requirements. Information is presented on the enabling legislation, the 

program elements, use of the programs, and impacts of the HOV, HOT, and managed lanes in 13 states. 

17. Key Words

HOV, HOT lanes, exempt vehicles, 

congestion, hybrids, tolled vehicles, 

lane degradation

18. Distribution Statement

No restrictions. 

19. Security Classif.(of this report)

Unclassified

20. Security Classif.(of this page)

Unclassified

21. No. of Pages

 40

22. Price

Form DOT F 1700.7 (8-72) Reproduction of completed page authorized

Technical Report Documentation Page

IMPACT OF EXEMPT VEHICLES ON 

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ii

IMPACT OF EXEMPT VEHICLES ON 

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Table of 

Contents

1.0. Introduction 1

1.1 Purpose 1

1.2 Background 1

1.3 Organization of Report 2

2.0 Summary of State Programs Allowing Exempt Vehicle Use of HOV/HOT Lanes 3

2.1 Similarities and Differences in Low-Emission and Energy Efficient Vehicle Programs 3

2.2 Other Exempt Vehicles 4

3.0 Case Studies of Exempt Vehicle Use by State 11

3.1 Arizona 11

3.2 California 12

3.3 Colorado 14

3.4 Florida 15

3.5 Georgia 16

3.6 Hawaii 17

3.7 Maryland 17

3.8 New Jersey 18

3.9 New York 18

3.10 North Carolina 19

3.11 Tennessee 19

3.12 Utah 20

3.13 Virginia 20

4.0 Issues/Considerations With Hybrid Vehicle Use of HOV/HOT Lanes 25

4.1 Other Exempt Vehicles 26

4.2 Report Summary 26

Appendix A - Acknowledgements 27 

Appendix B - References 29

List of Figures

Figure 1. Image. Virginia Clean Special License Plates 22

List of Tables

Table 1. HOT Lanes and Authorized Vehicles 6

Table 2. Freeway HOV Lanes and Authorized Vehicles 7

Table 3. Hybrid and ILEV Authorization by State 8

Table 4. Number of Annual Plug-In Vehicle HOV Permits Issued in Maryland 18

Table 5. Number of Active Virginia Clean Special Fuel License Plates 21

Introduction Summary of State 

Programs

Appendix BReferences

Case Studies Issues/

Considerations

Appendix AAcknowledgements

Appendix BReferences

IMPACT OF EXEMPT VEHICLES ON 

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IMPACT OF EXEMPT VEHICLES ON 

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1.0 Introduction

1.1 Purpose

The purpose of this report is to review the legislation and 

the programs in use by states allowing low-emission 

and energy efficient vehicles to access high-occupancy 

vehicle (HOV), high-occupancy toll (HOT), and 

managed lanes without meeting the vehicle-occupancy 

requirements. Information is presented on the enabling 

legislation, the program elements, use of the programs, 

and impacts on the HOV, HOT, and managed lanes. 

Information is also presented on the requirements 

contained in the Moving Ahead for Progress in the 21st 

Century Act (MAP-21) related to allowing these types 

of vehicles to use HOV, HOT, and managed lanes. The 

report should be of benefit to technical staff and policy 

makers interested in better understanding the use of 

HOV, HOT, and managed lanes by low-emission and 

energy efficient vehicles and other types of exempt 

vehicles.

1.2 Background

Traffic congestion continues to be a significant 

issue in metropolitan areas throughout the country. 

Transportation agencies at the federal, state, 

metropolitan, and local levels are using a variety of 

techniques and approaches to improve traffic flow, 

enhance mobility, and provide travel options. Managed 

lanes, including HOV and HOT lanes, are approaches 

being used in some areas to ease traffic congestion.

HOV lanes provide travel-time savings and improved 

trip-time reliability to encourage travelers to change 

from driving alone to carpooling, vanpooling, or riding 

the bus. HOT lanes expand the allowed user groups 

to include solo drivers or lower-occupant vehicles, who 

can access the lanes by paying a fee. HOV/HOT lanes 

improve the people-moving capacity of congested 

freeway corridors and provide mobility options to 

travelers.

HOV/HOT lane applications have evolved over the past 

40 years. Early projects focused primarily on bus-only 

facilities. Carpools became the dominate user group 

on most HOV lanes in the 1970s and 1980s. The 1990 

Clean Air Act Amendments and the Transportation Equity 

Act for the 21st Century (TEA-21) expanded potential 

user groups to include specific types of low-emission 

and energy-efficient vehicles. These efforts focused on 

providing incentives for the purchase and use of lowemission and energy-efficient vehicles.

The Safe, Accountable, Flexible, Efficient Transportation 

Equity Act: A Legacy for Users (SAFETEA-LU) 

allowed increased flexibility for state departments of 

transportation and other agencies in maximizing the use 

of HOV/HOT facilities when available capacity exists. 

SAFETEA-LU provisions expanded the definition of lowemission and energy-efficient vehicles to include some 

types of hybrid vehicles.

These provisions were continued in MAP-21, which 

also requires state agencies that allow tolled or lowemission and energy-efficient vehicles to use an HOV 

facility to submit to the Secretary of the U.S. Department 

of Transportation (U.S. DOT) a report demonstrating 

that the facility is not already degraded, and that the 

presence of the vehicles will not cause the facility to 

become degraded. Reporting that the number of 

permits or license plates issued is low is no longer 

sufficient. Agencies must monitor and certify that the 

HOV/HOT lanes meet the operating requirements or 

identify corrective action.

Agencies must also certify that they will establish, 

manage, and support a performance monitoring, 

evaluation, and reporting program for the HOV/HOT 

facilities. The program provides continuous monitoring, 

assessment, and reporting on possible vehicle impacts 

on the HOV facility and the adjacent highways. Further, 

state agencies must submit annual reports to the 

Secretary on those impacts. The agencies must 

also establish, manage, and support enforcement 

programs to ensure the HOV/HOT facility is operated 

in accordance with the requirements and that agencies 

limit or discontinue use of the HOV/HOT lanes by these 

types of vehicles whenever operations are degraded.

This requirement is a key addition – states must 

now certify that the HOV/HOT lanes are meeting the 

operating requirements, regardless of the number of 

low-emission and energy-efficient vehicles using the 

lanes. In addition, other exempt vehicles typically 

allowed to use HOV/HOT lanes with only the driver 

include police, emergency and public transit vehicles.

As of October 2013, 13 states — Arizona, California, 

Colorado, Florida, Georgia, Hawaii, Maryland, New 

Jersey, New York, North Carolina, Tennessee, Utah, and 

IMPACT OF EXEMPT VEHICLES ON 

MANAGED LANES 2014 01Introduction Summary of State 

Programs

Appendix BReferences

Case Studies Issues/

Considerations

Appendix AAcknowledgements

Appendix BReferences
Virginia – had legislation allowing some combination 

of low-emission and energy-efficient, plug-in electric, 

or hybrid gasoline-powered vehicles to access HOV 

and HOT lanes without meeting minimum occupancy 

requirements. This report summarizes these programs. 

Based on experiences in the 13 states, issues and 

considerations with the use of HOV/HOT lanes by these 

types of vehicles are also highlighted.

1.3 Organization of Report

The remainder of this report is divided into three sections. 

Section II provides a summary of state programs allowing 

exempt vehicles use of HOV/HOT lanes. These programs 

focus on hybrid, plug-in electric, and other low-emission 

and energy-efficient vehicles. It also highlights use of 

HOV/HOT lanes by police, emergency, and public transit 

vehicles with only the driver. Case studies of the states 

with legislation and programs allowing hybrid, plug-in 

electric, low-emission and energy-efficient vehicle access 

are presented in Section III. The report concludes with a 

discussion of issues and considerations with low-emission 

and energy-efficient vehicles use of HOV/HOT lanes in 

Section IV. Appendix A provides a list of references used 

in the report.

IMPACT OF EXEMPT VEHICLES ON 02 MANAGED LANES 2014
IMPACT OF EXEMPT VEHICLES ON 

MANAGED LANES 2014 03

2.0 Summary of State Programs Allowing 

Exempt Vehicle Use of HOV/HOT Lanes

As of October 2013, 13 states had legislation and 

programs allowing some combination of hybrid, plug-in 

electric, low-emission, and energy-efficient vehicles to 

use HOV/HOT lanes. These states included Arizona, 

California, Colorado, Florida, Georgia, Hawaii, Maryland, 

New Jersey, New York, North Carolina, Tennessee, Utah, 

and Virginia. The program requirements vary, including 

authorized vehicles, methods to designate vehicles 

(stickers or license plates), costs, limits on the number 

of stickers or license plates that can be issued, and 

restrictions on use of some HOV/HOT lanes.

Tables 1 through 3 highlight general information on 

HOV/HOT lane user groups and the key elements of 

the various programs. Table 1 presents the vehicles 

authorized to use HOT lanes in different states, while 

Table 2 provides the vehicles authorized to use HOV 

lanes. Table 3 presents information on the major 

elements of the exempt vehicle programs in the 13 

states; the HOV/HOT lanes covered by the programs, 

vehicles allowed, the authorization display methods, and 

any costs. Any limitations on the number of vehicles 

allowed by the programs, the number of stickers or 

license plates that can be issued, use as a percent of 

HOV/HOT lane volume, and the agency or agencies 

responsible for the programs are also listed. Similarities 

and differences in the approaches used in the programs 

are summarized next.

Information on the use of HOV/HOT lanes by law 

enforcement, emergency medical, and other exempt 

vehicles is presented at the end of this chapter.

2.1 Similarities and Differences in LowEmission and Energy Efficient Vehicle 

Programs

As highlighted in Table 3, the 13 programs focus on 

different types of hybrid, plug-in electric, low-emission, 

and energy-efficient vehicles and have different 

requirements. Key similarities and differences in the 

approaches are summarized in this section.

•	Exempt vehicle legislation in seven states – Arizona,

Hawaii, Maryland, New York, North Carolina, 

Tennessee, and Virginia – cover HOV lanes. Programs 

in California, Colorado, Georgia, Florida, and Utah 

include HOT lanes. The New Jersey program allows 

hybrid and other low-emission and energy-efficient 

vehicles to use the HOV lanes on the New Jersey 

Turnpike, but these vehicles must still pay the toll.

•	Although all states follow the U.S. Environmental

Protection Agency (EPA) guidelines related to lowemission and energy-efficient vehicles, there are 

differences in the models and makes of hybrid and 

alternative fuel vehicles (AFVs) allowed to use HOV/

HOT lanes. In Arizona, only three models – the Honda 

Insight, the Toyota Prius, and the Honda Civic Hybrid 

– met the Tier II emissions requirements and achieved 

not less than 45 percent fuel efficiency in combined 

city-highway fuel economy when the pilot program 

was initiated in 2007. Since it is an ongoing pilot, 

these models continue to be the only ones eligible for 

the program, although any model year qualifies. In 

comparison, the Florida program included almost 200 

eligible hybrids and other AFVs. Legislation in two 

states – Hawaii and Maryland – focuses on electric 

vehicle (EVs) and plug-in electric vehicles (PIVs or 

PEVs).

•	Four states – Arizona, Georgia, Hawaii, and Virginia

– use special license plates for qualifying hybrids 

and other AFVs. Seven states – California, Colorado, 

Florida, Maryland, New York, Tennessee, and Utah – 

use stickers, decals, or permits that must be displayed 

on a vehicle.

•	New Jersey does not use any display methods for

hybrid vehicles using the New Jersey Turnpike HOV 

lanes. Single-occupancy Hybrid vehicle drivers must 

still pay the toll, but have access to the HOV lanes.

•	Five states – Arizona, California, Georgia, Utah, and

Virginia – charge a fee for the exempt vehicle license 

plate or sticker. The fees range from a low of $8 in 

California, to a high of $25 in Virginia. No fees are 

charged with the programs in Colorado, Florida, 

Maryland, New Jersey, New York, and Tennessee. 

However, drivers must pay for toll transponders in 

Colorado and Florida, and New Jersey.

Introduction Summary of State 

Programs

Appendix BReferences

Case Studies Issues/

Considerations

Appendix AAcknowledgements

Appendix BReferences
•	California is the only state to allow legislation on hybrid

access to HOV lanes to expire. As of July 1, 2011, the 

85,000 hybrid vehicles with the yellow clean air vehicle 

stickers were no longer able to access the HOV lanes 

in the state without meeting the vehicle-occupancy 

requirements. The original legislation allowing 

HOV access to qualifying inherently low-emission 

vehicles (ILEVs) with white clean air vehicle stickers 

was extended until January 1, 2015. In addition, the 

legislation established a new green clean air vehicle 

sticker for vehicles meeting California’s enhanced 

AT-PZEV requirements. As noted previously, as of 

December 31, 2012, 8,859 green clean air vehicle 

stickers had been issued. Legislation passed in 2013 

extended the white and the green clean vehicle sticker 

programs until 2019.

•	Virginia is the only state to regulate hybrid vehicle use

of the HOV lanes by changing the clean special fuel 

license plate design and limiting hybrid vehicle access 

to specific HOV lanes based on the license plate 

design. There are currently three clean special fuel 

license plates in use in Virginia. Use of the HOV lanes 

in northern Virginia, which includes I-394, I-95, and 

I-66, is limited to certain license plates.

•	Information on the use of HOV/HOT lanes by exempt

vehicles is somewhat limited. Five states – California, 

Colorado, Florida, New York, and Virginia – have 

available data on use of the HOV/HOT lanes by 

exempt vehicles. Hybrids account for a little over 

2 percent of the total vehicles using the I-25 Express 

Lanes in Denver; 26-to-31 percent of peak hour HOV 

volumes on the Long Island Expressway in New York; 

and 10-to-24 percent of total HOV lane volumes on 

HOV lanes in northern Virginia.

2.2 Other Exempt Vehicles

Other exempt vehicles are allowed to use HOV/HOT 

lanes in most states. These typically include public 

transit buses with only the driver and marked (rooftop 

emergency lights and sirens) law enforcement and 

emergency vehicles with only the driver.

Public transit buses carrying passengers are important 

elements of most HOV/HOT lanes. Buses are carrying 

more people in fewer vehicles, adding to the peoplemoving capacity of HOV, HOT, and managed lanes. 

Public transit buses with only the driver, which are typically dead-heading or out of service to begin or end service, are allowed to use most HOV, HOT, and managed 

lanes. This approach provides operating efficiencies 

•	Three states – Arizona, California, and Colorado –

limit the number of license plates or stickers that can 

be issued to hybrids or other AFVs. Arizona initially 

allowed 10,000 special license plates to be allocated 

in the pilot program implemented in February 2007. 

The limit of 10,000 was reached in May 2008. In 2011, 

the Arizona Department of Transportation (ADOT) 

calculated that an additional 2,500 special license 

plates could be issued based on returned and nonrenewed plates. Available in September 2011, these 

additional 2,500 license plates were quickly taken. The 

2004 legislation in California allowing hybrids access to 

HOV lanes authorized 75,000 yellow clean air vehicle 

stickers. Subsequent legislation in 2006 allowed an 

additional 10,000 decals to be issued. There were 

85,000 stickers in use when the legislation was allowed 

to expire on July 1, 2011. The new green clean air 

vehicle stickers are limited to the first 40,000 vehicles 

meeting the new California Enhanced Advanced 

Technology – Partial Zero Emission Vehicle (AT-PZEV) 

requirements. As of December 31, 2012, 8,859 green 

clean air vehicle stickers had been issued. There 

are no limits on the number of white clean air vehicle 

stickers for California’s super ultra-low emissions 

vehicles (SULEV). As of December 31, 2012, 21,743 

white stickers had been issued. In Colorado, the 

number of orange stickers available for use of the HOV/

HOT lanes in the Denver area was limited to the first 

2,000 vehicles. This limit was reached in mid-2012.

•	The number of decals, stickers, or license plates

issued varies by state. California and Virginia have 

experienced the most demand, probably due to the 

trip-time savings and trip-time reliability afforded by 

the HOV lanes in the two states. California reached 

the legislatively imposed limit of 85,000 for the yellow 

hybrid stickers in mid-2006. The legislature allowed 

the yellow hybrid sticker program to expire on July 

1, 2011. Both the white stickers and the new green 

stickers continued to be issued, with 21,743 white 

stickers and 8,859 green stickers in circulation as 

of the end of 2012. Approximately 25,696 clean 

special fuel license plates were issued in Virginia as 

of October 2013, with use restricted by different HOV 

facilities. In comparison, approximately 12,500 special 

license plates have been issued in Arizona, which is 

the legislatively-imposed limit, and the limit of 2,000 

stickers has been reached in Colorado. Approximately 

1,300 hybrid decals have been issued in Nashville, 

5,555 C Decals have been issued in Utah, and 

approximately 20,000 hybrid decals have been issued 

for the Long Island Expressway (LIE) in New York, all of 

which have no limit.

IMPACT OF EXEMPT VEHICLES ON 04 MANAGED LANES 2014
and cost savings to the transit agencies and improved 

service for riders. Issues may arise, however, if taxicabs, 

airport shuttles, and other private transportation vehicles 

request the same access. No HOV/HOT lanes have 

been identified allowing these types of vehicles without 

meeting the occupancy requirement or paying a toll.

Marked law enforcement and emergency vehicles, which 

typically include police, sheriff, state patrol, emergency 

medical services (EMS), and other related vehicles, are 

allowed to use most HOV/HOT lanes without meeting the 

occupancy requirements. The use of HOV/HOT facilities 

by marked law enforcement and emergency vehicles 

appears to be relatively low and does not appear to be 

monitored. The use of HOV/HOT lanes by unmarked law 

enforcement and emergency vehicles or by law enforcement and emergency personnel traveling in their own vehicles was an issue on the HOV lanes in northern Virginia 

in the early 2000s.

IMPACT OF EXEMPT VEHICLES ON 

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The Code of Virginia provides an HOV exemption for law 

enforcement, but no specific definition of a law enforcement vehicle is provided in the state statute. The Virginia 

HOV Enforcement Task Force noted issues with the use 

of HOV lanes in northern Virginia by off-duty law enforcement and emergency personnel, as well as federal 

employees who consider themselves law enforcement 

personnel, traveling to and from work in their personal 

vehicles. Although the Task Force was not able to determine the number of these individuals, it is recommended 

that the statute be better defined and that education and 

outreach efforts be undertaken focused on these individuals. Outreach efforts were initiated which appear to 

have helped address the issue. 

Introduction Summary of State 

Programs

Appendix BReferences

Case Studies Issues/

Considerations

Appendix AAcknowledgements

Appendix BReferences
IMPACT OF EXEMPT VEHICLES ON 06 MANAGED LANES 2014

State/HOT Lanes Tolled Carpools Occupancy 

Requirement

Carpool

Registration Vanpools Buses Motorcycles

Alternative 

Fuel 

Vehicles

California1

San Diego – I-15

Bay Area – I-680

Los Angeles – I-10,

I-110

√ √ 2+, except I-10 – 

3+ peak period No √ √ √ SULEVs

AT-PZEVs

Colorado

Denver – I-25 √ √ 2+ No √ √ √ Qualifying 

Hybrids

Florida

Miami – I-95 √ √ 3+ Yes √ √ √ Qualifying 

Hybrids

Georgia2

Atlanta – I-85 √ √ 3+ Yes √ √ √ AFVs

Minnesota

Minneapolis – I-394,

I-35W

√ √ 2+ No √ √ √

Texas3

Houston – I-10W,

I-45S, I-45N, US 59S, 

US 59N, US 290

√ √ 2+ No √ √ √

Utah

Salt Lake City – I-15 √ √ 2+ No √ √ √ Qualifying 

Hybrids

Virginia

I-495 √ √ 2+ No √ √ √

Washington

Seattle – SR 167 √ √ 2+ No √ √ √

Source: Texas A&M Transportation Institute, 2013.

1 California currently allows vehicles that meet the state’s SULEV standards that quality for the White Clean Air Vehicle Sticker and enhanced AT-PZEV vehicles that qualify 

for the Green Clean Air Vehicle Sticker to use HOT lanes without meeting the vehicle-occupancy requirements. These vehicles are not allowed to use the HOT lanes 

(ExpressLanes) on I-10 and I-110, however, as these facilities are part of the federally-funded Congestion Reduction Demonstration (CRD) program.

2 Georgia currently allows AFVs to use the I-85 Express Lanes (HOT lanes), but hybrid vehicles are not included in the AFV definition.

3 The HOV/HOT lanes on I-45S (Gulf Freeway), I-45N (North Freeway), US 59S (Southwest Freeway), and US 290 (Northwest Freeway) are reserved for HOVs-only from 

7:00 a.m. to 8:00 a.m. and from 5:00 p.m. to 6:00 p.m. The HOV lanes on I-10W are part of the toll/managed lanes operated by the Harris County Toll Road Authority 

(HCTRA) in the freeway median. Buses, carpools, and vanpools have toll-free access weekdays from 5:00 a.m. to 11:00 a.m. and 2:00 p.m. to 8:00 p.m. 

Table 1. HOT Lanes and Authorized Vehicles
Massachusetts

I-93 √ 2+ √ √ √

New York

Long Island Expressway (LIE)

Staten Island Expressway 

(SIE)

√

2+ (LIE)

3+ (SIE)

√ √ √ Qualifying 

Hybrids (LIE)

North Carolina

Charlotte – I-77 √ 2+ √ √ √

PIV, natural 

gas, fuel cell 

electric

Pennsylvania

Pittsburgh – I-279/I-579 √ 2+ √ √ √

Tennessee

Nashville – I-65, I-40, I-24,

Memphis – I-40, I-55

√ 2+ √ √ √ Qualifying 

Hybrids

Texas

Dallas – I-30E, I-35E, I-635,

US 67

√ 2+ √ √ √

Virginia

Northern Virginia – I-95, I-395 √ 3+ √ √ √ Qualifying 

Hybrids

I-66, Dulles Toll Road 2+

IMPACT OF EXEMPT VEHICLES ON 

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State/HOV Lanes Carpools Occupancy

Requirement Vanpools Buses Motorcycles Alternative 

Fuel Vehicles

Arizona

Phoenix Area – I-10, I-71,

SR 51, SR 101, SR 202

√ 2+ √ √ √ Qualifying 

Hybrids

California1

Bay Area – SR 4, SR 84, SR 

85, SR 87, SR 92, SR 237, 

I-80, I-280, I-580, I-680, I-880, 

US 101

Sacramento – SR 51, SR 99, 

US 50, I-80

Los Angeles/Southern 

California – I-105, I-605, SR 

14, SR 22, SR 55, SR 57, SR 

60, SR 71, SR 91, SR 118, SR 

210, SR 134, SR 170, I-210, 

I-215, I-405, I-5, I-405

√

2+, except

Bay Bridge approach – 3+ √ √ √ SULEVs

AT-PZEVs

Colorado

Denver – US 36, SH 82, 

US 85

√ 2+ √ √ √ Qualifying 

Hybrids

Connecticut

Hartford – I-84, I-91, I-384 √ 2+ √ √ √

Georgia2

Atlanta – I-75, I-20 √ 2+ √ √ √ AFVs

Hawaii

Honolulu – H-201, H-1, H-2, 

Route 92, Route 72

√ 2+ √ √ √ EVs

Maryland

I-270, US 50 √ 2+ √ √ √ PIVs

Table 2. Freeway HOV Lanes and Authorized Vehicles 

Source: Texas A&M Transportation Institute, 2013.

1

California currently allows vehicles that meet the state’s SULEV standards that qualify for the White Clean Air Vehicle Sticker and enhanced AT-PZEV vehicles that qualify 

for the Green Clean Air Vehicle Sticker to use HOV lanes without meeting the vehicle-occupancy requirements.

2

Georgia currently allows AFVs to use HOV lanes on I-75 and I-20, but hybrid vehicles are not included in the AFV definition.

Introduction Summary of State 

Programs

Appendix BReferences

Case Studies Issues/

Considerations

Appendix AAcknowledgements

Appendix BReferences
State

Legislation/ 

Initiated

Facilities Vehicles

Allowed

Display

Method Cost Limit

Number 

Issued1

Percent 

of HOV/

HOT Lane 

Volumes1

Responsible

Agency

Arizona

1997 – AFVs

2001 – Hybrids

Phoenix area 

HOV lanes – 

I-10, I-17, SR 

51, SR 101, SR 

202, 

ILEVs, 

qualifying 

hybrids

Special 

license plate

$10.59 Arizona 

Department of 

Transportation

2007 – Pilot 

Initiated

10,000

additional 

2,500 issued

12,500 NI

California All HOV lanes 

in the state

California Air 

Resources Board, 

California 

Department of 

Motor Vehicles, 

California 

Department of 

Transportation

1999 – SULEVs SULEVs White clean 

air vehicle 

sticker

$8.00 No limit 21,743 5%-to15% of 

HOV lane 

volumes 

for white 

and yellow 

stickers

2004 – Hybrids

(Allowed to Expire 

July 1, 2011)

Hybrids Yellow clean 

air vehicle 

sticker 

$8.00 75,000 initially, 10,000 

added

85,000

2011 – Enhanced 

AT-PZEVs

AT-PZEVs Green clean 

air vehicle 

sticker

$8.00 40,000 8,859

Colorado

1998 – ILEVs

Denver area – 

U.S. 36, Santa 

Fe Drive

Colorado Department of Transportation, Colorado 

Department of 

Revenue

2003 – Hybrids SH 82 HOV 

lanes, and I-25 

Express Lanes

ILEVs, 

qualifying 

hybrids

Orange 

stickers, toll 

transponders

No 

cost for 

sticker, 

deposit 

for transponder

2,000 2,000 4% of HOV 

volume and 

2% of total 

vehicles 

on I-25 

Express 

Lanes

Florida

2003 –ILEVs and 

Hybrids (based 

on Federal Approval)

I-95 HOT lanes ILEVs, 

qualifying 

hybrids

Decal No cost No limit 3,722 1.5% of 

monthly 

trips, 55% 

of toll-exempt trips

Florida Department of Transportation,

Florida Department of Highway 

Safety and Motor 

Vehicles

Georgia

1991 – AFVs

2004 – Hybrids

Atlanta area – 

I-85, hybrid use 

not allowed

AFVs License 

plates/special 

tag

$20 

annual 

registration/

decal 

fee; $35 

special 

tag fee

No limit NI Use by 

AFVs not 

available

Georgia Department of Transportation, Georgia 

Department of 

Revenue

IMPACT OF EXEMPT VEHICLES ON 08 MANAGED LANES 2014

Table 3. Hybrid and ILEV Authorization by State
Hawaii Honolulu area 

– H-1, H-2, 

H-201, Route 

92, Route 72

EVs License 

plates

NI No Limit NI NI Hawaii 

Department of 

Transportation

Maryland I-270 and US 

50 HOV lanes 

PIVs Permit No Cost2 No Limit 988 NI Maryland 

Motor Vehicle 

Administration, 

State Highway 

Administration, 

Maryland 

Department of 

Transportation

New Jersey

2006 – Hybrids

2009 – Reconfirmed

New Jersey 

Turnpike HOV 

lanes

ILEVs, 

qualifying 

hybrids

No display Must still 

pay toll

No limit NI New Jersey 

Turnpike Authority

New York Long Island 

Expressway

Hybrids Decal No cost No limit 26%-to31% of 

peak hour 

HOV lane 

volumes

New York 

Department of 

Transportation, 

New York State 

Department of 

Motor Vehicles, 

New York State 

Department of 

Environmental 

Conservation

North Carolina Charlotte – I-77 PIVs, 

natural 

gas, 

fuel cell 

electric

NI NI NI NI North Carolina 

Department of 

Transportation

Tennessee

2009 – Hybrids

Nashville 

area – I-65, 

I-40, I-24 HOV 

lanes; Memphis 

area – I-40 and 

I-55-HOV lanes

Hybrids Decal No cost No limit 2,133 NI Tennessee 

Department of 

Revenue, 

Tennessee 

Department of 

Transportation

Utah

2001 – AVLs and 

Qualifying Hybrids

2011 – Modified 

to Match EPA 

Requirements

I-15 HOT Express Lanes in 

Salt Lake City

Qualifying 

hybrids

Decal 

(change from 

license plate)

$10 fee 

for C 

Decal

No limit 5,555 C 

Decals

NI Utah Department 

of Transportation

Virginia

1993 – AVLs

2000 – Hybrids

Northern Virginia – I-395, I-95, 

I-66, Dulles Toll 

Road; Hampton 

Roads – I-64,

SR 44

Qualifying 

hybrids

License plate $25 

fee for 

license 

plate

Use limited 

by plate type3

26,516 10%-to24% of 

HOV lane 

volumes 

in northern 

Virginia

Virginia 

Department of 

Transportation,

Virginia 

Department of 

Motor Vehicles

State

Legislation/ 

Initiated

Facilities Vehicles

Allowed

Display

Method Cost Limit Number 

Issued1

Percent 

of HOV/

HOT Lane 

Volumes1

Responsible

Agency

IMPACT OF EXEMPT VEHICLES ON 

MANAGED LANES 2014 09

Source: Texas A&M Transportation Institute, 2013.

1

N I – No information available.

2

The legislation in Maryland authorizes the Motor Vehicle Administration to charge an annual fee not exceeding $20 for a PIV permit. No fee is currently charged.

3

Virginia has three different designs of clean special fuel license plates. Use of the I-395 and I-95 HOV lanes in northern Virginia is limited to vehicles with clean special 

fuel license plates issued prior to July 1, 2006. Use of the I-66 HOV lanes is limited to the vehicles with clean special fuel license plated issues prior to July 1, 2006 

and the clean special fuel license plates issued prior to July 1, 2011.

Table 3. Hybrid and ILEV Authorization by State (Continued)

Introduction Summary of State 

Programs

Appendix BReferences

Case Studies Issues/

Considerations

Appendix AAcknowledgements

Appendix BReferences
IMPACT OF EXEMPT VEHICLES ON 10 MANAGED LANES 2014
Legislation allowing AFVs to use HOV lanes in Arizona 

was first approved in 1997. The definition of eligible 

AFVs at that time followed the provisions of TEA-21. 

Legislation approved in 2001 added hybrids to the types 

of qualifying vehicles based on approval from the federal 

government.

The initial request from ADOT to the Federal Highway 

Administration (FHWA) to include hybrid vehicles in the 

exempt HOV lane user group was not approved since 

hybrids were not allowed under TEA-21. Based on 

SAFETEA-LU, FHWA granted conditional approval to 

ADOT to allow hybrid vehicles use of HOV lanes. The 

governor authorized a pilot program in January 2007, 

allowing qualifying hybrid vehicles to use the HOV lanes, 

reducing travel times and improving trip-time reliability for 

individuals driving eligible vehicles. The pilot was also 

intended to promote energy independence, reduce fuel 

consumption, and support air quality.

The pilot program was initiated by ADOT in February 

2007. Vehicles meeting the Tier II emissions levels 

established under the Clean Air Act Amendments and 

achieving not less than 45 percent fuel efficiency in 

combined city-highway fuel economy were eligible for 

the pilot program. At the time, the Honda Insight, Toyota 

Prius, and Honda Civic Hybrid met the criteria. Only 

those makes and models continue to be eligible for the 

pilot program, although any model year qualifies.

The pilot program allows up to 10,000 qualifying hybrid 

vehicles to use the HOV lanes in the Phoenix area. 

Currently, HOV lanes are in operation on I-10, I-17, SR 

51, SR 101, and SR 202 in the Phoenix area. The HOV 

lanes operate on weekdays from 6:00 a.m. to 9:00 a.m. 

and from 3:00 p.m. to 7:00 p.m. The lanes are open to 

general purpose traffic at other times and on weekends.

Owners of eligible hybrid vehicles must obtain a special 

“blue sky” energy-efficient license plate with a hybrid 

decal. Initially, individuals were able to obtain an 

alternative-fuel license plate and decal on-line or through 

the mail. There is an $8.00 initial application fee and 

$1.50 charge for postage and handling.

The limit of 10,000 was reached in May 2008 and no 

further decals were issued. By 2011, ADOT calculated 

that 2,500 license plates could be made available due to 

those returned or not renewed. The second issuance of 

alternative-fuel license plates was opened on September 

13, 2011. License plates were available only through 

on-line registration at http://www.servicearizona.com/, 

on a first-come, first-served basis. The cost of the plates 

was $10.49, including postage and handling. The 2,500 

available plates sold out quickly. The following message 

is posted on the website. “Arizona’s Energy Efficient 

Pilot Program has reached the maximum limit of 10,000 

special license plates issued. There are no plates 

available at this time. Thank you for your interest in the 

program.”

Currently, the overall traffic volumes in the freeway 

HOV and general purpose lanes in the Phoenix area 

are monitored. Use of the HOV lanes by vehicles with 

energy-efficient license plates with hybrid decals is not 

monitored, however.

3.0 Case Studies of Exempt 

Vehicle Use by State

This section provides more detailed information on the exempt vehicle 

programs in the 13 states. Information on the enabling state legislation, 

program requirements, and permits or license plates issued is 

presented. Data on actual use by exempt vehicles is provided for those 

states with available information.

IMPACT OF EXEMPT VEHICLES ON 

MANAGED LANES 2014 11

3.1 Arizona

Source: Arizona Department of Transportation.

Introduction Summary of State 

Programs

Appendix BReferences

Case Studies Issues/

Considerations

Appendix AAcknowledgements

Appendix BReferences
IMPACT OF EXEMPT VEHICLES ON 12 MANAGED LANES 2014

California is the only state that has approved legislation 

allowing specific low-emissions vehicles to access HOV 

lanes, adding hybrid vehicles to the authorized group, 

and then allowing the exemption to expire. The legislation 

allowing the hybrid exemption to expire created a new 

program for the next generation of green technology 

vehicles, however.

Legislation approved in 1999 allowed vehicles meeting 

California’s low-emissions vehicle regulations to access 

HOV lanes in the state without meeting vehicle-occupancy 

requirements. Since few vehicles met these requirements, 

there was little impact on HOV lane use. Owners of 

vehicles meeting the federal ILEV definition were able 

to obtain white clean air vehicle stickers. No limit was 

placed on the number of white stickers that could be 

issued due to the anticipated low number of ILEVs. This 

program was continued in the legislation allowing hybrid 

vehicle use. Further, legislation passed in 2011 extended 

the white clean air vehicle sticker program through 

January 1, 2015.

Decaled vehicles have been exempt from tolls on HOT 

lanes in the state as a matter of practice and business 

rules. The exception is the I-10 and I-110 HOT lanes 

in Los Angeles County, which are part of the federal 

Congestion Reduction Management (CRD) program. 

Legislation in 2010 requires decaled vehicles using 

the I-10 and I-110 HOT lanes to pay the toll until the 

end of the federal demonstration period on March 1, 

2014. Legislation passed in 2012 was formally codified 

providing toll-free passage on HOT lanes to decaled 

vehicles, with the exception of I-10 and I-110.

Legislation approved in 2004 extended the HOV lane 

exemption to hybrid vehicles and other vehicles meeting 

the state’s AT-PZEV standard and having a 45 mpg or 

greater fuel economy highway rating. Implementation of 

this provision was based on federal action allowing hybrid 

vehicles.

The legislation directed the California Department of 

Transportation (Caltrans), the California Department 

of Motor Vehicles (DMV), the California Air Resources 

Board (CARB), and the California Highway Patrol (CHP) 

to develop and implement procedures for identifying 

exempt vehicles, administering the program, and 

monitoring use of HOV lanes. The legislation prohibited 

the DMV from issuing more than 75,000 yellow clean air 

vehicle stickers to hybrid vehicles and directed Caltrans 

to examine specific elements when 50,000 yellow stickers 

were issued.

As required by state legislation, Caltrans conducted 

an assessment when 50,000 yellow stickers had been 

issued to determine if significant HOV lane breakdown 

had occurred due to the addition of hybrid vehicles. 

The factors identified in the legislation to be examined 

included reduction in the level-of-service (LOS), sustained 

stop-and-go conditions, average travel speeds slower 

than the adjacent general purpose freeway lanes, and 

consistent increases in travel times in the HOV lanes.

The analysis focused primarily on the LOS measurement, 

as it is commonly used to assess freeway performance. 

A LOS C, which represents the threshold between 

acceptable operating conditions and breakdown 

conditions, was used in the determination study. 

Information on the number of permits issued by counties 

in the state was also examined.

A total of 25 counties accounted for 98 percent of the 

50,679 yellow clean air vehicle stickers issued by March 

2006. Los Angeles County accounted for 33 percent of 

the total, followed by Orange County with 10 percent, 

Santa Clara County with 8 percent, and San Diego and 

Alameda counties with 7 percent each. HOV lanes are 

located in all of these counties.

LOS data for a two-week period in April 2005 was 

compared with data for the same two-week period in 

2006. The assessment concluded that there was no 

significant HOV lane breakdown directly attributable to 

hybrid vehicle use of the HOV lanes.

The assessment found that approximately 88-to-90 

percent of the monitored HOV lanes operated at a LOS 

C or better during the morning and afternoon peak 

periods in 2006. Between 10 percent and 12 percent of 

the HOV lane miles experienced breakdown conditions 

in 2006. Approximately 7 percent of the HOV lane miles 

experienced breakdown conditions in 2005, prior to 

allowing hybrid access. While the operation of some 

3-to-5 percent of the HOV lane miles degraded from 2005 

to 2006, it was not possible to attribute the LOS decline 

directly to hybrid vehicles. Finally, the assessment 

indicated that the operating conditions improved in 

almost as many HOV lane miles as declined from 2005 

and 2006.

3.2 California

Source: Caltrans.
IMPACT OF EXEMPT VEHICLES ON 

MANAGED LANES 2014 13

In mid-2006, 75,000 yellow stickers had been issued and 

the DMV stopped issuing stickers. Legislation in 2006 

authorized an additional 10,000 yellow stickers to be 

issued. These extra yellow decals were quickly taken, 

bringing the total to 85,000 stickers issued.

The use of HOV lanes by hybrid vehicles was monitored 

as part of Caltrans’ ongoing data collection program. 

Traffic counts from 2006 on HOV lanes in Los Angeles 

and the San Francisco Bay Area indicate that hybrid 

vehicles accounted for between 5 percent and 15 

percent of total users during the morning peak hour. The 

highest volumes of 15 percent were recorded on I-405 

in Los Angeles. Peak hour hybrid volumes on SR-91, 

I-10, and I-605 in Los Angeles averaged approximately 

6 percent. Hybrid vehicle volumes on HOV lanes in the 

Bay Area were lower, representing approximately 

7 percent on I-80 and 5 percent on US 101.

The legislation providing hybrid access to the HOV 

lanes in the state was allowed to expire on July 1, 2011. 

After that date, hybrid vehicles with the yellow clean air 

stickers were no longer eligible to use the HOV lanes. 

Vehicles with the white clean air stickers are still eligible 

to use the HOV lanes.

The California DMV continues to issue white clean air 

vehicle decals for vehicles that meet California’s SULEV 

standard for exhaust emissions and the federal ILEV 

evaporative emissions standard, including certain zeroemissions vehicles. Additionally eligible for the white 

clean air vehicle decals are 2004 model year or older 

vehicles that meet the California ultra-low emissions 

vehicle (ULEV) standard for exhaust emissions and 

the federal ILEV standard and certain AT-PZEVs. As of 

December 31, 2012, 21,743 white clean air stickers had 

been issued.

In addition, as of January 1, 2012, the DMV began 

issuing green clean air vehicle stickers to the first 

40,000 applicants who purchase or lease vehicles 

meeting California Enhanced AT-PZEV requirements. 

The California Air Resources Board (CARB) identified 

vehicles meeting the requirements. As of December 31, 

2012, 8,859 green decals had been issued.

As required by MAP-21, Caltrans submitted an HOV 

lane degradation determination report and an HOV 

lane degradation action plan to the FHWA California 

Division in July 2013. The degradation determination 

report includes an analysis of the performance of HOV 

lanes in the state for 2011. The analysis is based on 

highway speed and volume data collected from the 

traffic monitoring system, which includes in-ground loop 

detectors and microwave vehicle detection systems. 

Data were collected and analyzed for two 180-day 

periods – January 1-to-June 20, 2011 and July 1-toDecember 31, 2011. The analysis covers the full 1,425 

lane-miles of HOV lanes in the state, although data were 

not available for all segments.

Overall, 43 percent of the HOV lane miles were identified 

as degraded in the first half of the year and 49 percent 

were degraded in the second half. The report notes 

that these figures partially reflect the general overall 

increase in congestion on the freeway system in the 

latter half of the year, especially after school begins in 

the late summer. Caltrans further examined the level of 

degradation, using the following three categories:

•	Slightly degraded – degradation occurs from 10-to-49

percent of the time, or approximately 2-to-9 weekdays 

per month;

•	Very degraded – degradation occurs from 50-to-74

percent of the time, equivalent to 10-to-15 weekdays 

per month; and

•	Extremely degraded – degradation occurs 75 percent

or more of the time, or approximately 16 days per 

month.

The report notes that on freeways with HOV lanes, 

approximately 13 percent of VMT in the morning peak 

hour were in the HOV lanes and approximately 15 

percent of the VMT in the afternoon peak hour were in 

the HOV lanes. The report further notes that given these 

use levels; it is difficult for Caltrans to meet the federal 

performance standard requirement. The report further 

notes that degradation in the HOV lanes increased after 

the sunsetting of the hybrid decal program.

The degradation action plan includes both shortterm and long-term strategies to reduce or eliminate 

degradation. The strategies include increasing 

enforcement, improving incident response times, 

improving detection, improving infrastructure, and 

implementing active traffic management (ATM) 

strategies. Infrastructure improvements include HOV 

lane gap closure projects, HOV lane extensions, and 

adding a second HOV lane. Changing occupancy 

levels may also be considered, but prohibiting ILEVs is 

not being considered at this time as it is counter to the 

Governor’s Executive Order to support and incentivize 

the purchase and use of these vehicles.

The report includes an analysis and action plan for each 

HOV lane in the state. The 2011 degradation level is 

provided, along with the potential causes. The planned 

remediation strategies are presented and the reasons for 

using the strategies are described.

Introduction Summary of State 

Programs

Appendix BReferences

Case Studies Issues/

Considerations

Appendix AAcknowledgements

Appendix BReferences
IMPACT OF EXEMPT VEHICLES ON 14 MANAGED LANES 2014

The I-25 HOV lanes were opened in the mid-1990s. 

Initially called the Downtown Express, the HOV lanes 

are seven miles in length. The barrier-separated facility 

includes two lanes with shoulders on each side. Access 

is provided at both ends of the lane. The lanes operate 

in the inbound direction toward downtown Denver in the 

morning and in the outbound direction in the afternoon. 

A 2+ vehicle-occupancy requirement is used.

In June 2006, toll paying solo drivers were allowed to 

use the re-named I-25 Express Lanes. The project uses 

electronic toll collection (ETC), with pre-set variable 

pricing by time-of-day. Solo drivers must obtain an 

EXpressToll transponder or new sticker tag and maintain 

an active account to use the Express Lanes. The 

transponders can also be used on the E-470 and the 

Northwest Parkway toll facilities.

A License Plate Toll was introduced in January 2009, 

providing another toll payment option. Cameras 

photograph the front and rear license plates of vehicles 

without an EXpressToll transponder or a new sticker tag. 

A bill is sent one month later to the registered owner 

of the vehicle for all trips made in the Express Lanes. 

Unpaid bills become accumulated civil penalties and 

notices of such are sent to the vehicle owner.

The current EXpressToll rates range from a low of $0.50 

on Saturdays, Sundays, and weekday off-peak periods 

to a high of $4.00 during the weekday morning and 

afternoon peak-periods. The License Plate Toll rate 

includes a surcharge of 25 percent or more on the 

EXpressToll rate. The License Plate Toll rates currently 

range from $0.75-to-$5.00. In June 2013, the High 

Performance Transportation Enterprise (HPTE) Board 

adjusted the toll rates by extending the morning peak 

period for another hour to 6:45 a.m. to 8:45 a.m.

Legislation adopted in 1998 allowed ILEVs meeting EPA 

standards to use HOV lanes in the state without meeting 

the minimum-occupancy requirements. Qualifying 

vehicles are required to display a Colorado Department 

of Transportation (CDOT)-developed circular bright 

orange sticker on the front windshield, the front driver’s 

side rear-view mirror, or the front bumper of the vehicle.

The legislation further required CDOT, in consultation 

with the Denver Regional Transportation District (RTD) 

and local authorities, to monitor use by ILEVs as part 

of their periodic LOS evaluations. CDOT or other 

authorities may restrict or eliminate HOV lane use 

by ILEVs if it is determined that ILEVs are causing a 

significant decrease in the LOS for HOVs. The legislation 

specifies that if the U.S. Secretary of Transportation 

makes a formal determination that allowing ILEVs to 

use HOV lanes would disqualify the state from receiving 

federal funds, the use shall be terminated.

Legislation approved in 2003 allows hybrid vehicles, 

along with ILEVs, to use HOV lanes without meeting 

the minimum-occupancy requirements. The legislation 

states that allowing hybrid vehicles to use HOV lanes 

shall apply only if such exemption does not affect the 

receipt of federal funds and does not violate any federal 

laws or regulations.

The Colorado Department of Revenue, Division of Motor 

Vehicles, issued “Rules for Establishing and Regulating 

the Use of HOV/HOT Lanes for Certain Hybrid Vehicles 

for the Use and Benefit of the Colorado Department 

of Transportation” in April 2008. The rules cover the 

statutory authority for allowing hybrid use of HOV/HOT 

lanes in the state, the identification and permitting of 

hybrid vehicles, and the duration of the program. The 

rules also address the vehicle use priority should the 

HOV/HOT lanes become congested due to access 

by hybrid vehicles. The rules further cap the number 

of hybrid permits to the first 2,000 qualifying hybrid 

vehicles. The hybrid vehicle program was initiated in 

May 2008.

The program was scheduled to follow the SAFETEA-LU 

authorization, which initially terminated on September 30, 

2009. The program continued following the SAFETEALU extensions, and the passage of MAP-21. The rules 

outline two types of identification for hybrid vehicle use 

of HOV/HOT lanes. First, hybrid vehicle owners must 

obtain the orange hybrid sticker. Hybrid vehicles with 

these stickers may access the HOV lanes on U.S. 36, 

Santa Fe Drive, and State Highway 82. Secondly, to use 

the I-25 Express Lanes a hybrid vehicle owner must also 

obtain an EXpressToll transponder or a new sticker tag. 

The transponder or tag records the hybrid vehicle as 

part of the automatic vehicle identification (AVI) system. 

When a qualifying hybrid vehicle accesses the I-25 

Express Lanes, the hybrid identification is read by the toll 

reader and the account is not charged.

3.3 Colorado

Source: Colorado Department of Transportation.
There is no cost to obtain a hybrid permit. Applications 

can be completed on-line or submitted through the 

mail. A deposit is required to obtain an EXpressToll 

transponder and establish an account. Since hybrid 

vehicles are not exempt from paying tolls on E-470 or 

the Northwest Parkway, the deposit covers possible use 

of those toll facilities. Further, charging hybrid vehicles a 

reduced toll is one option if the Express Lanes become 

congested. Additionally, the transponders are used as 

part of the data collection process to monitor congestion 

and free-flow conditions in the Express Lanes.

The hybrid permits and transponders are not 

transferable to another hybrid vehicle or to another 

owner. The permits and transponders must be returned, 

although an EXpressToll transponder can be retained by 

changing the vehicle’s status to a non-hybrid account.

By mid-2012, the 2,000 hybrid permit limit was 

reached. Individuals may still apply for a hybrid permit. 

Applications are placed on a waiting list and new 

permits are issued as existing permits are returned. The 

CDOT I-25 Express Lanes website alerts individuals 

that the 2,000 permit quota has been reached, but that 

applications are still being accepted. The website also 

contains a reminder for individuals to contact CDOT if 

they no longer own a hybrid vehicle with an authorized 

permit and transponder or tag.

Use of the I-25 Express lanes is monitored by CDOT. 

Quarterly reports are published, which include 

information on vehicle volumes, bus travel times, 

revenues and expenditures, incidents, enforcement, 

operational issues, and hybrid utilization. The quarterly 

reports for July – September 2012, October – December 

2012, January – March 2013, and April – June 2013 

indicate that the number of daily hybrid users has 

remained relatively constant over the 12-month period.

Daily use of the Express Lanes by hybrid vehicles 

averaged between 161 and 179 vehicles a day, with 

slightly heavier use in the morning operating periods. 

The maximum daily hybrid use was between 250 

and 296 vehicles. The average total daily traffic in 

the Express Lanes over the same time period was 

approximately 10,000 vehicles. Approximately 65 

percent of the daily traffic is HOVs and hybrid vehicles, 

and 36 percent are toll-paying vehicles. Hybrid vehicles 

represent approximately 4 percent of the HOV volume 

and 2 percent of the total vehicles.

Legislation approved in 2003 allowed ILEVs that 

are certified and labeled in accordance with federal 

regulations to use HOV lanes in the state without meeting 

the minimum-occupancy levels. The legislation allowed 

hybrid vehicles to use the HOV lanes without meeting the 

occupancy requirements based on federal authorization. 

As a result, hybrid vehicles have been allowed to use 

HOV lanes in the state since the passage of SAFETEALU. 

At the time, HOV lanes were in operation on I-95 in 

Miami-Dade, Broward, and Palm Beach counties. 

Based on legislative direction, the Florida Department 

of Transportation (FDOT) and the Florida Department 

of Highway Safety and Motor Vehicles established a 

process to issue a decal and a registration certificate on 

an annual basis to owners of hybrid and other qualifying 

vehicles for HOV lane access. Hybrid vehicle owners 

must complete an application for an HOV decal and 

submit it to a county tax collector office. In addition, as 

noted in the following, hybrid owners must register to use 

the 95 Express lanes on I-95.

FDOT sponsored a study in 2002 examining the 

potential influence of the anticipated ILEV legislation 

on the I-95 HOV lanes. The study found that ILEVs 

currently comprise a very small portion of the vehicle 

fleet in Florida and therefore would not impact HOV lane 

performance. The study also concluded that, based 

on limited experience in other states, allowing ILEVs to 

use HOV lanes provides an incentive for the purchase 

of these vehicles, but not enough to affect HOV lane 

performance. The study further noted that the number of 

ILEVs in the state should not increase significantly based 

on current definitions, but that the zero-evaporative 

emissions regulations could have a significant impact on 

ILEV sales and thus use of HOV lanes in the future. No 

specific study was conducted examining hybrid use of 

HOV lanes.

IMPACT OF EXEMPT VEHICLES ON 

MANAGED LANES 2014 15

3.4 Florida

Introduction Summary of State 

Programs

Appendix BReferences

Case Studies Issues/

Considerations

Appendix AAcknowledgements

Appendix BReferences

Source: Battelle
Approximately seven miles of the HOV lanes on I-95 

in Miami-Dade County were expanded into HOT lanes 

with funding through the federal Urban Partnership 

Agreement (UPA). The project converted the single 

HOV lanes in both directions to two HOT or express 

lanes in each direction. Called the 95 Express, the 

lanes are open to toll-paying customers with an active 

SunPass account. Variable tolling is used to maintain 

free-flow conditions in the express lanes. Registered 

vanpools, registered 3+ carpools, and registered hybrid 

vehicles can use the 95 Express without paying a toll. 

Registered transit buses, school buses, and over-theroad coaches may also use the 95 Express toll-free. 

Additionally, motorcycles can use the 95 Express tollfree and do not need to register.

FDOT monitors use of the 95 Express and publishes 

monthly operations reports. As of September 2013, 

8,978 toll-exempt vehicle registrations had been 

processed for the 95 Express. Hybrid vehicles 

accounted for 3,722, or 41 percent, of the registered 

toll-exempt vehicles. In comparison, the other 

registered toll-exempt vehicles included 3+ carpools, 

27 percent; Miami-Dade school buses, 19 percent; 

Broward County and Miami-Dade County public transit 

buses, 11 percent; over-the-road coaches, 1.8 percent; 

and vanpools, 0.2 percent.

A total of 1,722,467 vehicle trips were recorded using 

the 95 Express in September 2013. A total of 44,609, 

or 2.6 percent, of these trips were made by toll-exempt 

vehicles. Hybrid vehicles accounted for 58 percent of 

these toll-exempt trips, compared to 24 percent by all 

types of registered buses, 14 percent by 3+ HOVs, 

2 percent by motorcycles, and 2 percent by vanpools. 

These results indicate that hybrid vehicles represent 

approximately 25,873, or 1.5 percent, of the total 

monthly trips on the 95 Express.

3.5 Georgia

Legislation approved in 1997 allows AFVs to use HOV 

lanes in Georgia without meeting vehicle-occupancy 

requirements. Vehicles must meet requirements 

designated by the Georgia Department of Natural 

Resources. Legislation approved in 2004 extended 

eligibility to electric hybrid vehicles but provided 

that single-occupant hybrids could not use the HOV 

lanes unless Congress amended the existing federal 

legislation or action was taken by the U.S. Department 

of Transportation. Currently, the Georgia Department of 

Transportation’s (GDOT) web page with AFV and HOV 

information notes that hybrid vehicles do not qualify for 

an AFV tag. Thus, single-occupant hybrid vehicles are 

not allowed to use the HOV lanes in the state, including 

the I-85 Express HOT lanes.

To use the HOV lanes, owners of AFVs must obtain 

an AFV license plate and tag from the Georgia 

Department of Revenue. An owner must complete 

a vehicle request form, stating the type of fuel used 

to propel the vehicle. The owner must also indicate 

the primary location where the alternative fuel will be 

purchased, and affirm that the vehicle will operate on 

the alternative fuel not less than 85 percent of the total 

time the vehicle is in operation. Owners are required 

to maintain receipts for purchases of alternative fuel 

for three years and provide them as requested for 

compliance review. The 2010 special license plate 

information chart lists the following costs for an AFV 

license plate – annual registration/decal fee, $20; 

manufacturing fee, $20; special tag fee, $35; and 

special tag renewal fee. These fees are similar to those 

for the other special license plates. No inspection of 

the vehicle is required. 

The I-85 Express Lanes, which expanded the I-85 

HOV lanes to HOT lanes in 2011 as part of the federal 

CRD program, allows vehicles with proper AFV license 

plates, which do not include hybrids. No data was 

available on the number of plates issued by the 

Georgia Department of Revenue or on the use of the 

I-85 Express Lanes by vehicles with AFV license plates.

IMPACT OF EXEMPT VEHICLES ON 16 MANAGED LANES 2014

Source: Georgia Department of Transportation.
Legislation passed in 1997 provided a number of 

incentives for electric vehicle ownership in Hawaii. 

These incentives include use of the HOV lanes in 

the state without meeting the vehicle-occupancy 

requirements and exemption from parking fees charged 

by any non-federal governmental authority. Motor 

vehicle registration fees were also waived on electric 

vehicles for a five-year period after passage of the act. 

HOV lanes are in operation in the Honolulu area on H-1, 

H-2, H-201, Route 92, and Route 72. Motor vehicles are 

registered by county in Hawaii. Individuals purchasing 

or importing electric vehicles obtain an electric vehicle 

license plate when they register their vehicle. Drivers of 

these vehicles are then able to use the HOV lanes. No 

data is available on the use of the HOV lanes in Hawaii 

by electric vehicles.

3.6 Hawaii

3.7 Maryland

Legislation passed by the Maryland General Assembly 

in 2010 allows plug-in electric vehicles (PIVs) to use 

HOV lanes in the state without meeting the vehicleoccupancy requirements. Currently, HOV lanes are in 

operation on I-270 and US 50. The PIVs must be titled 

and registered in Maryland, and must display a valid 

HOV permit. To quality for use of the HOV lanes, PIVs 

must also meet the following six criteria:

•	The vehicle must be made by a manufacturer and be

manufactured primarily for use on public streets, roads 

and highways;

•	The vehicle can be modified from the original

manufacturer’s specifications to a plug-in electric 

vehicle. Modified vehicles must be examined by the 

Maryland State Police prior to the issuance of a HOV 

permit;

•	Is rated at not more than 8,500 pounds unloaded

gross vehicle weight;

•	Has a maximum speed capability of at least 65 miles

per hour;

•	Is propelled to a significant extent by an electric motor

that draws electricity from a battery that has a capacity 

of not less than 4 kilowatt hours for four-wheeled 

vehicles and not less than 2.5 kilowatt hours for twoor three-wheeled motor vehicles; and

•	The vehicle is capable of being recharged from an

external source of electricity.

HOV lanes currently operate on I-270 and US 50 in 

Maryland. Operation of the HOV lanes on I-270 was 

initiated in September 1993 with the opening of the HOV 

lane on the northbound East Spur. The HOV lanes were 

completed in December 1996. The southbound HOV 

lane on I-270 extends from I-370 to Capital Beltway 

(I-495). The northbound HOV lane extends from the 

Capital Beltway to MD 121 (Clarksburg Road). The HOV 

lanes operate in peak periods, peak direction of travel – 

from 6:00 a.m. to 9:00 a.m. in the southbound direction 

and from 3:30 p.m. to 6:30 p.m. in the northbound 

direction. The HOV lanes are open to general purpose 

traffic at other times. The HOV lanes on US 50 opened 

in October 2002. The US 50 HOV lanes extend from the 

Capital Beltway to US 301 (Crain Highway), a distance 

of 7.5 miles. The HOV designation is in effect 24-hours 

a day/7 days a week.

The legislation authorized the Maryland Motor Vehicle 

Administration (MVA) to issue PIV permits. Vehicle 

owners must complete an application for a PIV permit. 

Although the legislation authorizes the MVA to charge 

up to $20 for a PIV permit, no fee is currently being 

assessed. The MVA currently provides the HOV permits/

stickers to PIV dealerships for them to distribute to PIV 

buyers. The MVA also provides HOV PIV permits to 

qualifying PIV owners who did not purchase their vehicle 

at a dealership. The PIV HOV permits currently expire 

on September 30, 2017, when the law is scheduled to 

sunset.

The legislation requires that the MVA and State Highway 

Administration (SHA) issue a joint report annually to the 

governor and the General Assembly on the effect of 

IMPACT OF EXEMPT VEHICLES ON 

MANAGED LANES 2014 17Introduction Summary of State 

Programs

Appendix BReferences

Case Studies Issues/

Considerations

Appendix AAcknowledgements

Appendix BReferences

Source: Battelle

Source: Battelle
PIV use of the HOV lanes. The reports document the 

number of HOV permits issued to PIVs. The December 

2013 report notes that 988 permits were issued between 

October 2010 and September 2013 as highlighted in 

Table 4. According to the MVA, there are 1,764 PIVs 

registered in Maryland. Approximately 56 percent of the 

PIVs in the state have registered for an HOV permit. The 

highest registration was recorded in September 2013, 

with 124 PIV HOV permits issued.

IMPACT OF EXEMPT VEHICLES ON 18 MANAGED LANES 2014

Year Number of PIV Permits Issued

20101 1

2011 120

2012 460

20132 407

Total 988

The SHA did not conduct a formal study of the impacts 

of the PIVs on the two HOV lanes based on only 988 

permits issued. The SHA concluded that this number of 

permits has no impact on HOV operations at the current 

time. The report notes that even if all 988 PIVs used the 

HOV lanes at the same time, the impact on operation of 

the lanes would be marginal. The report further notes 

the growth in the production and sales of PIVs and the 

need for ongoing monitoring.

3.8 New Jersey

The New Jersey Turnpike Authority allows hybrid 

vehicles to use the HOV lanes on the turnpike without 

meeting the vehicle-occupancy requirement. The hybrid 

access was first authorized by the New Jersey Turnpike 

Authority in 2006 and re-confirmed in 2009. The HOV 

lanes are located on the turnpike between Interchange 

11 in Woodbridge and Interchange 14 in Newark. The 

HOV lanes operate on weekdays in the northbound 

direction from 6:00 a.m. to 9:00 a.m. and in the 

southbound direction from 4:00 p.m. to 7:00 p.m. Hybrid 

vehicles must still pay the appropriate tolls, but may use 

the HOV lanes during the restricted time periods. No 

special tags, stickers, license plates, or transponders are 

required.

The list of qualifying hybrids is provided to enforcement 

personnel who monitor the use of the HOV lanes. 

Eligible hybrids include the Ford Escape Hybrid, Mazda 

Tribute Hybrid, Toyota Prius Hybrid, Toyota Highlander 

Hybrid, Honda Insight Hybrid, Honda Civic Hybrid, 

Honda Accord Hybrid, and Lexus RX400H. Use of the 

HOV lanes by hybrid vehicles is not monitored since the 

owners must still pay the appropriate toll.

3.9 New York

1

October-December 2010.

2

January-September 2013.

The Clean Pass pilot program, which began in 2006, 

allows eligible hybrid vehicles to use the HOV lanes 

on the Long Island Expressway (LIE). Clean Pass was 

initiated as part of the then governor’s Strategic Energy 

Action Plan. The LIE Clean Pass is sponsored through 

a partnership involving the New York State Department 

of Transportation (NYSDOT), the New York State 

Department of Motor Vehicles (NYSDMV), and the State 

Department of Environmental Conservation (DEC).

Owners of eligible hybrid vehicles apply to the NYSDMV 

to register for the program. The NYSDMV issues four 

stickers to eligible vehicle owners, which must be placed 

on the front, rear, and each side of the vehicle.

The NYSDMV and the NYSDOT monitor a number of 

elements of the Clean Pass program. The NYSDMV 

tracks the total Clean Pass vehicles registered statewide 

and by county. The number of hybrid vehicles 

registered in the state by county is also recorded. A 

comparison can be made of eligible hybrid vehicles by 

county and registered Clean Pass vehicles by county 

using these data. Sales of hybrid vehicles in the U.S. 

are monitored using commercially-available information.

Source: New York State Department of Transportation.

Table 4. Number of Annual Plug-In Vehicle HOV Permits Issued 

in Maryland

Source: Texas A&M Transportation 

Source: Battelle
IMPACT OF EXEMPT VEHICLES ON 

MANAGED LANES 2014 19

A total of 2,119 Clean Pass stickers were issued by the 

end of 2006. A total of 19,895 Clean Pass stickers had 

been issued as of October 1, 2013. Approximately 94 

percent of the eligible vehicles in Suffolk County and 64 

percent of the eligible vehicles in Nassau County have 

been registered for the program.

NYSDOT has an ongoing program monitoring use of 

the LIE. Traffic counts from October, 2006, indicate 

that hybrid vehicles accounted for between 15-to-90 

vehicles or 1 percent and 6 percent of the HOV lane 

volumes during the morning and the afternoon peak 

hours. Traffic counts in 2010 and 2011 indicate that 

the number of Clean Pass vehicles had increased to 

between 400 and 500 of the 1,500-to-1,600 vehicles 

using the LIE HOV lanes during the morning peak hour. 

As of October 2013, there was a maximum of 681 Clean 

Pass vehicles at exit 50, with an average of 551 Clean 

Pass vehicles across the length of the HOV lanes. The 

eastbound peak had a maximum of 520 Clean Pass 

vehicles at exit 50, with an average of 405 Clean Pass 

vehicles across the length of the HOV lanes. Thus, 

Clean Pass vehicles currently account for approximately 

26-to-31 percent of all peak hour vehicles using the LIE 

HOV lanes. The percent of carpools using the LIE has 

declined over this same time period.

3.10 North Carolina

Legislation passed in 2011 by the General Assembly 

of North Carolina allows PIVs, dedicated natural gas 

vehicles, and fuel cell electric vehicles to use the HOV 

lanes in the state without meeting the vehicle-occupancy 

requirements. The legislation does not include hybrid 

vehicles. Currently, the only HOV lanes in North Carolina 

are on I-77 in the Charlotte area. The North Carolina 

Department of Transportation website notes that gaselectric hybrid vehicles are not allowed to use the HOV 

lanes.

The HOV Smart Pass program was initiated in 2009, 

allowing hybrid vehicles to use the HOV lanes in the 

state without meeting the occupancy requirements. 

HOV lanes are currently in operation on I-65, I-40, and 

I-24 in Nashville and on I-40 and I-55 in Memphis. The 

Tennessee Department of Revenue is responsible for 

the Smart Pass program; the Tennessee Department 

of Transportation (TDOT) is responsible for planning, 

designing, and operating the HOV lanes; and the 

Tennessee Department of Safety is responsible for 

enforcing the HOV lanes.

Owners of hybrid and other qualifying vehicles can 

apply for a Smart Pass decal at no cost by 

e-mail, fax, or mail. The decal must be displayed 

to drive in an HOV lane without meeting the vehicleoccupancy requirement. The required placement of the 

decal is the outside of the rear vehicle window on the 

lower right or passenger side.

As of November, 2013, 2,133 HOV Smart Pass decals 

had been issued by the Tennessee Department of 

Revenue. TDOT does not currently collect data on use 

of the HOV lanes by vehicles with HOV Smart Pass 

decals. Plans are underway to begin collecting these 

data, however.

3.11 Tennessee

Source: Tennessee Department of Revenue.

Introduction Summary of State 

Programs

Appendix BReferences

Case Studies Issues/

Considerations

Appendix AAcknowledgements

Appendix BReferences

Source: Battelle
3.12 Utah

IMPACT OF EXEMPT VEHICLES ON 20 MANAGED LANES 2014

Legislation approved in 2001 allowed vehicles with 

clean fuel special group license plates to use HOV 

lanes in the state without meeting minimum-occupancy 

requirements. The initial exemption was scheduled to 

expire December 31, 2005, but was continued through 

legislative extensions. To qualify for a clean fuel license 

plate, a vehicle must meet EPA standards. An applicant 

must annually obtain a clean fuel vehicle permit. As of 

the fall of 2004, there were approximately 659 active 

vehicle registrations with clean fuel license plates in the 

state. This figure includes AFVs in agency fleets. 

Based on new state legislation, the Utah Department 

of Transportation (UDOT) began issuing a Clean Fuel 

Vehicle Decal to new applicants on July 1, 2011. The 

new C Decal program replaced the clean fuel license 

plate program for hybrid access to the I-15 Express 

Lanes with only the driver and without paying a toll. The 

change was made because the definition of “clean fuel” 

used in the previous legislation did not match the more 

stringent federal definition.

Individuals with an existing clean fuel license plate 

were notified if their vehicle did not qualify for a new C 

Decal. These individuals did not receive a new permit 

and C Decal. Individuals with an existing clean fuel 

license plate whose vehicle did qualify under the new 

requirements received a new C Decal. Individuals with 

qualifying vehicles can continue to obtain C Decals, 

as UDOT determined the I-15 Express Lanes can still 

accommodate additional C Decal vehicles without 

impacting carpools and HOT vehicles. As of November 

2013, 5,555 C Decals had been issued to hybrid 

vehicles, as well as compressed natural gas (CNG) and 

electric vehicles. No data was found on the use of the 

I-15 Express Lanes by vehicles with the C Decals.

3.13 Virginia

Virginia was the first state to allow hybrid vehicles to 

use HOV lanes without meeting vehicle-occupancy 

requirements. Hybrid vehicles have been able to access 

HOV lanes in the state since 2000, before it was allowed 

by federal legislation. Virginia provides a good example 

of an extensive ongoing HOV lane monitoring program 

conducted through the coordinated efforts of the Virginia 

Department of Transportation (VDOT), the Metropolitan 

Washington Council of Governments (WASHCOG), 

and the Virginia State Patrol. This monitoring program 

documented congestion in the HOV lanes in northern 

Virginia from hybrid use. Virginia has addressed this 

congestion by changing the clean special fuel license 

plate design and limiting hybrid vehicle access to 

specific HOV lanes based on the license plate design.

HOV lanes are in operation in northern Virginia and in 

the Hampton Roads, Norfolk, and Newport News area 

in southeastern Virginia. Three of the HOV lanes in 

northern Virginia – I-95, I-395, and I-66 – serve traffic 

in and out of Washington, D.C. The fourth HOV lane 

in northern Virginia is on the Dulles Toll Road, which 

feeds into I-66. HOV lanes in the Hampton Roads area 

include I-64 and I-264.

Legislation approved in Virginia in 1993 established 

a clean special fuel license plate for AFVs. State 

legislation approved in 1994 allowed vehicles with 

clean special fuel license plates to use the HOV lanes 

in Virginia without meeting the minimum-occupancy 

requirements. Subsequent legislation has extended the 

sunset date for the HOV lane access and limited use 

of some HOV facilities by changing the design of the 

required clean special fuel license plate. Three different 

special fuel license plates are currently in use. In 2013, 

the Virginia General Assembly extended the exemption 

indefinitely. The 2013 legislation also requires that 

the exemption must be compliant with federal laws. It 

further requires that the Commissioner of Highways 

shall provide annually to the Chairman of the Senate 

Source: Utah Department of Transportation. Source: Battelle
IMPACT OF EXEMPT VEHICLES ON 

MANAGED LANES 2014 21

and House of Delegates Committees on Transportation 

traffic volumes on the HOV facilities that result in a 

degradation condition as defined by federal law and as 

reported to FHWA.

Hybrid vehicles, which became available in the state 

in 2000, were initially determined not to be eligible for 

the clean special fuel license plates by the Virginia 

DMV, in consultation with the Virginia Department 

of Environmental Quality. After several citizens 

approached their state legislators about the issue, the 

decision was reversed.

Only vehicles with clean special fuel license plates are 

authorized to use the HOV lanes in Virginia without 

meeting the occupancy requirements. An individual 

must apply to the Virginia DMV for the special plates. 

A vehicle owner must submit the application and 

documentation to the DMV headquarters Special 

License Plate and Consignment Center. Staff at the 

Center review the application and documentation and 

determine if the vehicle qualifies for the clean special 

fuel license plate. The special plates and an invoice are 

sent to the owner of qualifying vehicles.

Table 5 presents the number of active clean special 

fuel license plates for different time periods. During 

the six years from 1994 through 1999 when only AFVs 

qualified, there were 78 active clean special fuel license 

plates. By June 2006, with hybrids qualifying for the 

HOV exemption, there were 15,485 clean special fuel 

license plates. By June 2011, there were 26,829 active 

clean special fuel license plates issued. The number of 

active clean special fuel license plates declined slightly 

to 25,646 in October 2013.

This increase was directly attributed to hybrid vehicle 

owners applying for the clean special fuel license 

plates. Hybrid vehicles account for 99.2 percent of the 

total active clean special fuel license plates. Further, 

84.4 percent of the existing special fuel vehicle plates 

were issued in counties and cities in northern Virginia, 

which are served by the I-95, I-395, I-66, and Dulles Toll 

Road HOV lanes.

WASHCOG, in coordination with VDOT, has an ongoing 

program for monitoring and reporting on the use of 

HOV facilities in northern Virginia. In the fall of 2003, 

clean special fuel vehicles accounted for between 

2 percent and 12 percent of the HOV volumes during 

the peak periods on the different HOV facilities in 

northern Virginia.

Counts from October 2004 indicated that clean special 

fuel vehicles accounted for between 11 percent and 

17 percent of the vehicles in the I-95 HOV lanes 

during the 6:00 a.m.-to-9:00 a.m. peak period in the 

northbound direction. These percentages translate 

into a range of 844-to-1,422 vehicles with clean special 

fuel license plates using the HOV lanes during the 

three-hour period, and the corresponding total vehicle 

volumes in the HOV lane ranged from 7,994 to 8,450. 

In 2005 and 2006, hybrid vehicles accounted for 

approximately 24 percent of the peak-hour vehicles 

using the I-95 HOV lane.

The Virginia HOV Enforcement Task Force examined 

hybrid vehicle use of the HOV lanes and other issues. 

The Task Force was established in 2003 by the Virginia 

Secretaries of Transportation and Public Safety in 

response to concerns from numerous groups about 

the large numbers of non-HOV vehicles in the HOV 

lanes during the restricted time period. The Task Force 

included representatives from state, regional, and local 

transportation and enforcement agencies. Reports 

issued by the Task Force in 2003 and 2005 included 

recommendations for addressing these concerns.

In an effort to limit or cap the number of clean fuel 

vehicles using the I-95/I-395 HOV lanes, legislation 

approved in 2006 required that a new distinctively 

different design be used for clean special fuel license 

plates issued after July 1, 2006. The legislation limits 

the clean fuel exemption on the HOV lanes in the 

I-95/I-395 corridor to vehicles registered with and 

displaying the clean special fuel license plates issued 

prior to July 1, 2006. Individuals with clean special fuel 

license plates registered to vehicles before July 1, 2006 

are able to renew or transfer their plates to a newly 

purchased qualifying vehicle after July 1, 2006 and 

continue to use the I-95/I-395 HOV lanes.

Year

Number of Active 

Clean Special Fuel 

License Plates

1994 – 19991 78

2000 – June 20062 15,485

July 2006 – June 20113 26,829

July 2011 – January 20124 26,516

February 2012 – October 2013 25,646

1

 Only AFVs eligible for clean special fuel license plates and allowed to use all HOV lanes in 

the state.

2

 Hybrid vehicles eligible for clean special fuel license plates and allowed to use all HOV lanes 

in the state.

3

 New clean special fuel license plates design implemented on July 1, 2006. Use of the HOV 

lanes on I-95 and I-395 limited to vehicles with the old clean special fuel license plates.

4

 Third clean special fuel license plate design implemented on July 1, 2011. Use of the HOV 

lanes on I-66 limited to vehicles with the first two clean special fuel license plates.

Table 5. Number of Active Virginia Clean Special Fuel 

License Plates

Source: Texas A&M Transportation 

Introduction Summary of State 

Programs

Appendix BReferences

Case Studies Issues/

Considerations

Appendix AAcknowledgements

Appendix BReferences
IMPACT OF EXEMPT VEHICLES ON 22 MANAGED LANES 2014

The legislation also increased the fee for the clean 

special fuel license plates from $10 to $25. For each 

$25 fee collected after the first 1,000 registrations, $15 

is paid to the State Treasurer and credited to a special, 

non-revenue HOV Enforcement Fund for use by the 

Virginia State Police for enhanced HOV enforcement.

In October 2010, hybrid vehicles accounted for between 

13.3-to-14.8 percent of peak hour vehicles on I-66 

inside the Beltway and 10-to-14.6 percent of peak hour 

vehicles on I-66 outside the Beltway. On I-395, hybrid 

vehicles accounted for between 11.8 percent and 14.1 

percent and between 13.9 percent and 15.3 percent on 

I-95.

The hybrid volumes on I-66 resulted in legislation 

establishing a new clean special fuel license plate and 

limiting use of I-66 to vehicles with either the special fuel 

I-95 and I-395 – Only vehicles 

with clean special fuel license 

plates issued before July 1, 

2006 (with the image on the left 

side of the plate) are allowed to 

use the HOV lanes on I-95 and 

I-395. These plates may only 

be renewed or transferred to 

a newly-purchased qualifying 

vehicle.

Figure 1 illustrates the three different clean special fuel license plates currently in use. The restriction on use of the 

different HOV lanes is also summarized.

I-66 – Only vehicles with clean 

special fuel license plates issued 

before July 1, 2006, and clean 

special fuel license plates issued 

after July 2, 2006 and before July 

1, 2011 (with the image on the 

right side of the plate), are allowed 

to use the I-66 HOV lanes. Both 

types of plates can be renewed or 

transferred to a newly-purchased 

qualifying vehicle

Dulles Toll Road and I-64 and 

I-264 in Hampton Roads – 

Vehicles with all types of clean 

special fuel license plates can 

use the HOV lanes on the Dulles 

Toll Road and on I-64 and I-264 in 

Hampton Roads. In addition to 

the two clean special fuel license 

plates noted above, the third 

license plate (with the image in 

the middle of the plate) has been 

issued since July 1, 2011. It is 

currently available for qualified 

hybrid vehicles.

Clean Special Fuel License Plates

Figure 1. Image. Virginia Clean Special License Plates Source: Virginia Department of Transportation.

license plates issued before July 1, 2006 or between 

July 1, 2006 and July 1, 2011. As noted previously, use 

of the HOV lanes in the state by vehicles with all of the 

clean special fuel license plates is currently scheduled 

to expire on July 2, 2012, although the Virginia General 

Assembly is considering extending this date.

As presented in Table 5, the number of active clean 

special fuel license plates in January 2012 and October 

2013 recorded a decline from the number in June 2011. 

As of July 1, 2011, hybrid vehicle owners applying 

for new clean special fuel license plates can only use 

the HOV lanes on the Dulles Toll Road and those in 

the Hampton Road areas, not the HOV lanes on I-95, 

I-395, and I-66. It appears the restrictions on use of 

the HOV lanes in the congested travel corridors serving 

Washington, D.C. have lowered the demand for the 

clean special fuel license plates.
IMPACT OF EXEMPT VEHICLES ON 

MANAGED LANES 2014 23

VDOT’s June 2013 report on HOV hybrid exemption 

certification indicates that HOV lanes in the 

Commonwealth are operating within the requirements of 

MAP-21, with the exception of I-66 outside the Beltway. 

The analysis, which examined operation of the HOV 

lanes from April 1-to-June 30, 2013, found I-66 to be 

degraded approximately 20 percent of the time in the 

morning peak period and almost 31 percent in the 

afternoon peak-period. 

The VDOT degradation mitigation plan for I-66 outside 

the Beltway includes five phases. These phases are 

increasing HOV enforcement and public awareness, 

improving available capacity management by 

implementing ATM and reducing merge activities, 

adding managed lanes, discontinuing clean fuel (nonHOV) vehicles, and increasing the vehicle-occupancy 

requirements from 2+ to 3+.

Introduction Summary of State 

Programs

Appendix BReferences

Case Studies Issues/

Considerations

Appendix AAcknowledgements

Appendix BReferences
IMPACT OF EXEMPT VEHICLES ON 24 MANAGED LANES 2014
IMPACT OF EXEMPT VEHICLES ON 

MANAGED LANES 2014 25

4.0 Issues/Considerations With Hybrid 

Vehicle Use of HOV/HOT Lanes

The experiences from states allowing hybrids and/or 

AFVs to access HOV and HOT lanes without meeting 

vehicle-occupancy requirements provide insight 

into possible issues that may be encountered with 

these programs. As highlighted in this section, these 

issues include creating congestion in the HOV/HOT 

lanes, reducing carpooling, causing confusion among 

user groups, addressing hybrid vehicles from other 

states, determining the eligible hybrid and AFVs, and 

expanding HOV lanes to HOT lanes. Consideration 

of these issues and possible approaches to address 

them prior to allowing hybrid access is important. 

Communicating this information to hybrid owners, other 

HOV/HOT users, and policy makers is also important to 

provide realistic expectations if changes in operations or 

user groups need to be made.

•	Congestion in the HOV/HOT Lanes. The addition of 

hybrid vehicles to HOV/HOT lanes already operating 

at or near capacity may cause congestion and 

reduce the travel-time savings and trip-time reliability 

historically provided to HOVs – buses, vanpools, 

and carpools. MAP-21 requires that state agencies 

demonstrate that an HOV facility is not already 

degraded and that the pressure of low-emission and 

energy-efficient vehicles will not cause the facility to 

become degraded. They must also report annually 

on HOV lane use and develop mitigation plans to 

address any degradation. In Virginia, this issue 

occurred and was initially addressed by legislation 

establishing new clean special fuel license plates, 

which limited access to individual HOV facilities based 

on the different license plates. Further, both California 

and Virginia have developed degrading mitigation 

plans to address specific concerns with allowing these 

vehicles to access HOV lanes in both states.

•	Reducing Carpooling. Current carpoolers who 

can afford to purchase a hybrid vehicle may do so 

solely to use an HOV/HOT lane, thus diminishing 

the intent of supporting carpooling. While no formal 

surveys have been conducted documenting existing 

carpoolers, vanpoolers, or bus riders purchasing 

hybrid vehicles primarily to use HOV/HOT lanes, the 

trends on the LIE indicates that carpool use of the 

HOV lanes has decreased while permits for hybrid 

vehicles have increased. The purchase of hybrid 

vehicles and applications for clean special fuel license 

plates are much higher in northern Virginia than in the 

Hampton Roads area, and use of the HOV lanes in 

northern Virginia by drivers of hybrid vehicles is much 

higher than the HOV lanes in Hampton Roads.

•	Causing Confusion among User Groups. Changing 

requirements for use of HOV/HOT lanes by hybrid 

vehicle owners may cause confusion among different 

user groups. Changing the clean special fuel license 

plate designs and limiting access to different HOV 

lanes in northern Virginia adds complexity to the 

program and may make it more difficult for users 

to understand. The Dr. Gridlock column in the 

Washington Post has addressed questions from 

individuals purchasing or thinking of purchasing a 

hybrid vehicle, only to find out that they are not able to 

use the HOV lanes on I-95, I-395, and I-66.

•	Hybrid Vehicles from Other States. The HOV/

HOT lanes in some areas, such as northern Virginia 

and New York, are very close to adjacent states and 

may serve multi-state travel patterns. Residents 

owning qualifying hybrid vehicles in adjacent states 

have questioned why they are not allowed to use 

these HOV/HOT lanes. For example, the Maryland 

State Highway Administration HOV website warns 

that hybrid vehicles with Maryland license plates are 

not allowed to use the HOV lanes in Virginia. NonNew York residents have written their congressmen 

questioning why out-of-state hybrid vehicle owners are 

not allowed to use the LIE HOV lanes.

•	Establishing Hybrid Vehicle Eligibility. While 

the EPA and additional state requirements provide 

guidelines for establishing hybrid vehicle eligibility, 

vehicle manufacturers and owners have challenged 

these guidelines and test procedures when their 

vehicles were not deemed eligible. For example, 

there has been disagreement over the Chevy Volt not 

being classified as eligible for the Clean Pass pilot 

program on the LIE in New York. GM and Volt owners 

have argued that the emissions and fuel economy 

was not tested in the way many people actually drive 

the Volt. The Volt operates solely on electricity for the 

first 40 miles. The gasoline engine begins powering 

the vehicle after 40 miles. Individuals driving the Volt 

for less than 40 miles and recharging it before their 

next trip, argue it never uses gasoline, and thus never 

generates any emissions. As a result, they argue, that 

Introduction Summary of State 

Programs

Appendix BReferences

Case Studies Issues/

Considerations

Appendix AAcknowledgements

Appendix BReferences
IMPACT OF EXEMPT VEHICLES ON 26 MANAGED LANES 2014

the Volt is effectively an “all electric” vehicle and should 

be classified as eligible.

•	HOV Lane to HOT Lane Expansion. The “free pass” 

given to hybrid vehicles in HOV lanes may be an 

issue when those HOV lanes are expanded to HOT 

lanes. Similarly, the development of new HOT lanes 

in states allowing hybrid access to HOV lanes may 

present issues. HOT lanes introduce toll collection, 

and thus, introduce elements of revenue generation. 

Allowing hybrid vehicles to use HOT lanes without 

paying the toll reduces revenues, while increasing 

vehicle volumes. For example, qualifying hybrids are 

currently able to access the I-95 Express Lanes in 

Miami, the I-25 Express Lanes in Denver, and the I-15 

Express Lanes in Salt Lake City, which are all HOT 

lanes, without paying a toll or meeting the vehicleoccupancy requirements. Qualifying hybrid vehicles 

were allowed to use the previous HOV lanes on I-95 

and I-15, while the program allowing qualifying hybrids 

to use the I-15 Express Lanes, as well as HOV lanes 

in Denver, was initiated after the expansion to HOT 

lanes. In another example, vehicles with white and 

green clean air vehicle stickers in California can use 

the I-25 HOT lanes in San Diego and the I-680 HOT 

lanes in the Bay Area without paying a toll. Vehicles 

with AFV license plates and tags are allowed to use 

the I-85 Express Lanes in Atlanta. In all of these cases, 

the potential loss of revenues is weighed against the 

state’s initiatives to encourage the sale and use of 

environmentally-friendly vehicles.

4.1 Other Exempt Vehicles

Other exempt vehicles are allowed to use HOV, HOT, and 

managed lanes in most states. These typically include 

public transit buses with only the driver and marked 

(rooftop emergency lights and sirens) law enforcement 

and emergency vehicles with only the driver.

Public transit buses carrying passengers are important 

elements of most HOV, HOT, and managed lanes. Buses 

are carrying more people in fewer vehicles, adding to 

the people-moving capacity of HOV, HOT, and managed 

lanes. Public transit buses with only the driver, which 

are typically dead-heading or out of service to begin or 

end service, are allowed to use most HOV, HOT, and 

managed lanes. This approach provides operating 

efficiencies and cost savings to the transit agencies and 

improved service for riders. Issues may arise, however, if 

taxicabs, airport shuttles, and other private transportation 

vehicles request the same access. No HOV, HOT, or 

managed lanes were identified in the literature review 

allowing these types of vehicles without meeting the 

occupancy requirement or paying a toll.

Marked law enforcement and emergency vehicles, 

which typically include police, sheriff, state patrol, EMS, 

and other related vehicles, are allowed to use most 

HOV, HOT, and managed lanes without meeting the 

occupancy requirements. The use of HOV facilities 

by marked law enforcement and emergency vehicles 

appears to be relatively low and does not appear to be 

monitored.

The use of HOV, HOT, and managed lanes by unmarked 

law enforcement and emergency vehicles or by law 

enforcement and emergency personnel traveling in their 

own vehicles was an issue on the HOV lanes in northern 

Virginia in the early 2000s. The Code of Virginia provides 

an HOV exemption for law enforcement, but no specific 

definition of a law enforcement vehicle is provided in 

the state statute. The Virginia HOV Enforcement Task 

Force noted issues with the use of HOV lanes in northern 

Virginia by off-duty law enforcement and emergency 

personnel, as well as federal employees who consider 

themselves law enforcement personnel, traveling to and 

from work in their personal vehicles. Although the Task 

Force was not able to determine the number of these 

individuals, it recommended that the statute be better 

defined and that an education and outreach effort be 

undertaken focused on these individuals. Outreach 

efforts were initiated which appear to have helped 

address the issue.

4.2 Report Summary

The purpose of this report was to review the programs in 

use by states allowing low-emission and energy efficient 

vehicles, and other exempt vehicles, access to HOV, 

HOT, and managed lanes without meeting the vehicleoccupancy requirements. Possible issues to consider 

with allowing low-emission and energy efficient vehicles 

to use HOV, HOT, and managed lanes was summarized. 

MAP-21 regulations require that states must submit a 

report that the facility is not already degraded, and that 

the presence of the vehicles will not allow the facility 

to become degraded are discussed, along with the 

requirement for ongoing monitoring and certification that 

the facilities meet the operating requirements.

The report should be of benefit to personnel responsible 

for planning and operating HOV, HOT, and managed 

lanes, as well as policy makers. The variety of 

approaches being used by states, and the differences 

in impacts, should be of interest to others considering 

new programs or changes in existing programs. The 

information highlights that states have the authority to 

develop programs that best meet their needs within 

the oversight provided by MAP-21 and the federal 

government.
IMPACT OF EXEMPT VEHICLES ON 

MANAGED LANES 2014 27

A number of individuals assisted with the preparation of this report. Mr. Neil Spiller, Federal Highway 

Administration (FHWA) served as the Government Task Manager (GTM) providing guidance throughout the 

project. A peer development group assisted in the preparation of the report by providing information on the 

case studies, participating in conference calls, and reviewing draft sections of the report. Members of the peer 

development group included Kari Grant, Colorado Department of Transportation; Rebecca Gibson, New York 

State Department of Transportation; Monica Kress and Joe Rouse, California Department of Transportation; 

Valerie Pardo, Virginia Department of Transportation; Stephanie Wiggins, Los Angeles Metropolitan Transportation 

Authority; and John Doan, Atkins. Kylynn Slayton, Gar Dingess, Tami Hannahs, Bonnie Duke and Gary Lobaugh, 

Texas A&M Transportation Institute, provided document layout, word processing and editing assistance, 

respectively. The assistance of all of these people is both recognized and appreciated. 

Appendix A - Acknowledgements

Introduction Summary of State 

Programs

Appendix BReferences

Case Studies Issues/

Considerations

Appendix AAcknowledgements

Appendix BReferences
IMPACT OF EXEMPT VEHICLES ON 28 MANAGED LANES 2014
IMPACT OF EXEMPT VEHICLES ON 

MANAGED LANES 2014 29

1. Moving Ahead for Progress in the 21st Century (MAP-21). http://www.gpo.gov/fdsys/pkg/PLAW-112publ141/pdf/

PLAW-112publ141.pdf. 

 

2. Chandra, A., S. Gulati, and M. Kandliker. Green Drivers or Free Riders? An Analysis of Tax Rebates for Hybrid 

Vehicles. Unpublished, Working Paper, 2009. 

3. Gallahger, K., and R. Muehlegger. Giving Green to Get Green: Incentives and Consumer Adoption of Hybrid 

Vehicle Technology. Unpublished, Faculty Research Working Paper Series, Harvard University, 2008.

4. Diamond, D. “The Impact of Government Incentives for Hybrid-Electric Vehicles: Evidence from U.S. States.” 

Energy Policy, 37: 972-983, 2009.

5. Diamond, D. “Impact of High Occupancy Vehicle (HOV) Lane Incentives for Hybrids in Virginia.” Journal of Public 

Transportation, Vol. 11, No. 4. Center for Urban Transportation Research, University of South Florida, Tampa, 

Florida, 2008.

6. Shewmake, S., and L. Jarvis. Hybrid Cars and HOV Lanes. University of California, Davis, 2009.

7. Breiland, C., C. Lianyu, and H. Benouar. “Operational Effect of Single-Occupant Hybrid Vehicles in HighOccupancy Vehicle Lanes.” Transportation Research Record: Journal of the Transportation Research Board, No. 

1959. Transportation Research Board of the National Academies, Washington, D.C., pp. 151-158, 2006.

8. Brownstone, D., L. Chu, T. Golob, K. Nesamani, and W. Recker. Evaluation of Incorporating Hybrid Vehicle Use of 

HOV Lanes. California PATH Program Research Report UCB-ITS-PRR-2008-26. Institute of Transportation Studies, 

University of California, Berkeley, Berkeley, California, 2008.

9. Jang, K., and M. Cassidy. Dual Influences on Vehicle Speeds in Special-Use Lanes and Policy Implications. 

University of California, Berkeley Center for Future Urban Transport. Institute of Transportation Studies, University 

of California, Berkeley, September 2011.

10. Arizona State Legislation, Senate Bill 1002. http://www.azleg.state.az.us/ FormatDocument.asp?inDoc=/

legtext/42leg/7s/bills/sb1002s%2Ehtm&DocType=B (link no longer available).

11. Arizona State Legislation, Senate Bill 1004. http://www.azleg.state.az.us/legtext/44leg/7s/bills/sb1004s.pdf.

12. Arizona State Legislation, Senate Bill 1429. http://www.azleg.state.az.us/legtext/45leg/1r/bills/sb1429s.pdf.

13. California State Legislation, Assembly Bill 2628. http://www.calcog.org/2004%20Agendas%20&%20

Minutes/040524mtg/ab_2628_bill_20040401_amended_asm.pdf (link no longer available).

14. California State Legislation, Chapter 330.

15. Alan C. Lloyd, chairman, California Air Resources Board, memorandum, May 18, 2000, Low-Emission Vehicles 

Permitted to Access High-Occupancy Vehicle (HOV) Lanes Under Assembly Bill 71 (AB71).

16. California Department of Motor Vehicles. Vehicle Code – Low-Emission Vehicle Identification for High-Occupancy 

Vehicle Lane Use: Tolls. http://www.dmv. ca.gov/pubs/vctop/d03/vc5205_5.htm.

17. California Department of Transportation, Division of Traffic Operations. Determination Report: Hybrids on the HighOccupancy Vehicle Facilities in California. Sacramento, CA, June 30, 2006. 

Appendix B - References

Introduction Summary of State 

Programs

Appendix BReferences

Case Studies Issues/

Considerations

Appendix AAcknowledgements

Appendix BReferences
IMPACT OF EXEMPT VEHICLES ON 30 MANAGED LANES 2014

18. California Department of Transportation. Hybrids in the HOV Lanes Traffic Counts, Los Angeles Freeways, April, 

2006.

19. California Department of Transportation. Traffic Counts, I-80 and US 101, April, 2006.

20. California Department of Transportation, 2011. California High-Occupancy Vehicle Lane Degradation Determination 

Report. July 31, 2013.

21. California Department of Transportation, 2011. California High-Occupancy Vehicle Lane Degradation Action Plan. 

July 31, 2013.

22. Colorado State Legislation, Senate Bill 30 (1998). http://www.state.co.us/ gov_dir/leg_dir/sess1998/sbills98/sb030.

htm.

23. Colorado State Legislation, Senate Bill 91 (2003). http://www.leg.state.co.us/2003a/inetcbill.nsf/fsbillcont/AD9789B

9458EF99387256C780069ECEB?Open&file=091_enr.pdf (link no longer available).

24. Colorado Department of Revenue Division of Motor Vehicles. 1CCR 204-28. Rules for Establishing and Regulating 

the Use of HOV/HOT Lanes for Certain Hybrid Vehicles for the Use and Benefit of the Colorado Department of 

Transportation. April 20, 2008.

25. I-25 Express Lane FY 2013 1st Quarter Performance Report, Quarterly Report July – September, 2012. Colorado 

High Performance Transportation Enterprise, September 2012.

26. I-25 Express Lane FY 2013 2nd Quarter Performance Report, Quarterly Report October – December 2012. 

Colorado High Performance Transportation Enterprise, December 2012.

27. I-25 Express Lane FY 2013 3rd Quarter Performance Report, Quarterly Report January – March 2013. Colorado 

High Performance Transportation Enterprise, December 2012.

28. I-25 Express Lane FY 2013 3rd Quarter Performance Report, Quarterly Report April – June 2013. Colorado High 

Performance Transportation Enterprise, June 2013.

29. I-25 HOV/Tolled Express Trends – 2006 to Present. Colorado High Performance Transportation Enterprise, June 20, 

2012.

30. Florida State Legislation, Senate Bill 88 (2003). http://www.flsenate.gov/data/session/2003/Senate/bills/billtext/pdf/

s0088.pdf (link no longer available).

31. Chris Porter, Anita Vandervalk, and Michael Williamson, Cambridge Systematics, Inc. to Jeff Weidner, Florida 

Department of Transportation, memorandum, October 12, 2002, “Analysis of the Impact of Inherently Low-Emission 

Vehicles on I-95 High-Occupancy Vehicles Lanes.”

32. FDOT District Six – 95 Express Monthly Operations Report, September 2013. Florida Department of Transportation, 

November 1, 2013.

33. Georgia State Legislation, Senate Bill 116. http://www.legis.state.ga.us/ legis/1997_98/leg/fulltext/sb116.htm.

34. Georgia State Legislation, House Bill 719, Section 2. http://www.legis.state. ga.us/legis/2003_04/fulltext/hb719.htm.

35. State of Hawaii. Act 290, Section 4, July 1, 1997.

36. Plug-In America. Hawaii EV Ready – Guidebook for Commercial Electric Vehicle Charging Station Installations. May 

2012.
IMPACT OF EXEMPT VEHICLES ON 

MANAGED LANES 2014 31

37. Maryland General Assembly, HB 674/SB 602 Authorizing Plug-In Vehicles with a State Permit to Use HOV Lanes, 

2010 Session.

38. Motor Vehicle Administration and State Highway Administration, Maryland Department of Transportation, 4th 

Annual Report to the Maryland Governor and General Assembly Regarding the Effects of the Use of Permits 

Issued to Plug-In Electric Vehicles on the Operation of HOV Lanes, December 2013.

39. New York State Department of Transportation. Long Island Expressway (I-495) HOV Lanes. January, 2007.

40. Utah State Legislation, House Bill 289. http://www.le.state.ut.us/~2001/bills/hbillint/HB0289S1.pdf (link no longer 

available).

41. Kevin Park, Utah Department of Motor Vehicles, E-mail to Author, December 13, 2004.

42. Virginia State Legislation, Section 33.1-462.

43. Virginia State Legislation, House Bill 585/Senate Bill 274. http://leg1.state.va.us/cgi-bin/legp504.

exe?961+ful+HB585, http://leg1.state.va.us/cgi-bin/legp504.exe?961+ful+SB274.

44. Virginia Department of Motor Vehicles Clean Special Fuel License Plate Data. June, 2011.

45. Virginia Department of Transportation, HOV and Hybrid Data Counts. 2004.

46. Virginia Department of Transportation, HOV and Hybrid Data Counts. 2005 and 2006.

47. High-Occupancy Vehicle Enforcement Task Force. Report of the High-Occupancy Vehicle Enforcement Task 

Force. Virginia Department of Transportation, Richmond, Virginia, August 15, 2003.

48. High Occupancy Vehicle Enforcement Task Force. Report of the High-Occupancy Vehicle Enforcement Task 

Force. Virginia Department of Transportation, Richmond, Virginia, January 4, 2005.

49. Virginia Department of Transportation, October 2010 Hybrid Counts, e-mail to author from Valerie Pardo, 

September 14, 2011. 

50. Virginia Department of Transportation. HOV Hybrid Exemption Certification Report. June 2013. 

Introduction Summary of State 

Programs

Appendix BReferences

Case Studies Issues/

Considerations

Appendix AAcknowledgements

Appendix BReferences
IMPACT OF EXEMPT VEHICLES ON 32 MANAGED LANES 2014

U.S. Department of Transportation

Federal Highway Administration

Office of Operations (HOP)

1200 New Jersey Avenue, SE

Washington, DC 20590

FHWA-HOP-14-006

January 15, 2014