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Potential Impact of Exempt Vehicles on HOV Lanes

compact car METRO bus

HOV lane in use

Prepared for the
Federal Highway Administration
By the
Texas Transportation Institute

August 2005

NOTICE

This document is disseminated under the sponsorship of the Department of Transportation in the interest of information exchange. The United States Government assumes no liability for its contents or use thereof.

Technical Report Documentation Page

1. Report No.
FHWA-HOP-05-058

2. Government Accession No.

3. Recipient's Catalog No.

4. Title and Subtitle
Potential Impact of Exempt Vehicles on HOV Lanes

5. Report Date
August 2005

6. Performing Organization Code

7. Author(s)
Katherine F. Turnbull

8. Performing Organization Report No.
Report

9. Performing Organization Name and Address

Texas Transportation Institute
The Texas A&M University System
College Station, TX 77843-3135

Prime Contractor:
Battelle
505 King Ave.
Columbus, Ohio 43201-2693

10. Work Unit No.

11. Contract or Grant No.
DTFH61-01-C-00182

12. Sponsoring Agency Name and Address
Office of Transportation Policy Studies
Federal Highway Administration
Room 3324, HTPS, 400 Seventh Street, S.W.
Washington, D.C. 20590

13. Type of Report and Period Covered
Research:

14. Sponsoring Agency Code

15. Supplementary Notes
Patrick DeCorla-Souza and Angela Jacobs, FHWA, Office of Transportation Policy Studies, Contracting Officer Technical Representative (COTR)

16. Abstract

This report explores the use of high-occupancy vehicle (HOV) lanes by exempt vehicles, including Inherently Low-Emission Vehicles (ILEV), environmentally friendly vehicles, law enforcement and emergency vehicles, and designated public transportation vehicles. Potential issues and approaches for allowing these types of exempt vehicles to use HOV lanes are examined. This information could be of use to state departments of transportation and other agencies in considering possible HOV exemption policies, and in monitoring and evaluating the use of HOV lanes by exempt vehicles.

As authorized in recent federal legislation, at least 10 states have approved legislation allowing ILEVs to use HOV lanes without meeting the minimum occupancy requirement. Additional legislation in five states includes hybrid vehicles in the HOV lane exemption, if allowed by federal laws or federal agency regulations. Contrary to federal law, Virginia already allows hybrid vehicles to use HOV lanes in the state. The available information examined in this report indicates that the use of HOV lanes by ILEVs is low. However, based on monitoring hybrid vehicle use of the HOV lanes in northern Virginia there is evidence that hybrids are contributing to congestion problems on some facilities.

Clearly marked law enforcement and emergency services vehicles, equipped with rooftop emergency lights and sirens, and designated public transportation vehicles are allowed to use most HOV facilities. There does not appear to be any major issues with the use of HOV lanes by these types of vehicle. However, there do appear to be issues in some areas with the unauthorized use of HOV lanes by law enforcement and emergency services personnel traveling in their personal vehicles or in unmarked agency vehicles while not on duty.

17. Key Words
HOV facilities, high-occupancy vehicle lanes, carpool lanes, energy-efficient vehicles, low-emission vehicles.

18. Distribution Statement
No restrictions. This document is available to the public through NTIS:
National Technical Information Service
5285 Port Royal Road
Springfield, Virginia 22161

19. Security Classif.
(of this report)
Unclassified

20. Security Classif.
(of this page)
Unclassified

21. No. of Pages
81

22. Price

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

LIST OF FIGURES

LIST OF TABLES

REPORT OVERVIEW

CHAPTER ONE—INTRODUCTION

OBJECTIVES OF STUDY

BACKGROUND

ACTIVITIES CONDUCTED