High-occupancy vehicle (HOV) lanes are one or more lanes of a roadway that have restrictions on use to encourage ridesharing and can reduce vehicle miles traveled (VMT). Rules for HOV lanes vary and are usually posted. Typically, HOV lanes are open to motor vehicles carrying two or more people, and sometimes access is open to motorcycles or vehicles that use alternative fuels (hybrid or electric vehicles). Access restrictions on HOV lanes can apply 24-hours a day or only during peak congestion periods. The goal of HOV lanes is to provide an incentive to use ridesharing and public transportation, remove congestion from normal lanes of travel, and improve overall traffic operations. In places with excess capacity on HOV lanes, high-occupancy toll (HOT) lanes have been implemented. These differ from HOV lanes in that motor vehicles carrying only one person can use these lanes for a fee. Users may be able to use HOT lanes at all times that HOV lanes are in operation or HOT lane use may be restricted during the most congested periods.
Related Transportation and Heath Tool Indicators
How can this strategy result in health benefits?
- Address chronic disease (e.g., asthma, diabetes, heart disease)
- Reduce transportation's contribution to air pollution
How has this worked in practice?
The Metropolitan Transit Authority of Harris County (METRO) operates a total of 120 miles of HOV lanes serving Houston and the surrounding eight-county region. The Houston region’s HOV network was built primarily for buses. It also promotes ridesharing through vanpools and carpools, including METRO’s RideSponsor (employer-based commuter program), RideShare (ride-matching for vanpools/carpools), and METRO STAR vanpool programs. The METRO HOV system is predominantly HOV-2 (minimum 2 occupants), with some corridors designated HOV-3 (minimum 3 occupants) during peak hours. The system includes both barrier-protected lanes and lanes designated by pavement markings. A 2006 report found that METRO's HOV lanes (consisting of 113 miles at the time) handled almost 118,000 person trips each weekday, by serving about 36,400 multi-occupant vehicle trips. The report found that the HOV lanes had lower average travel times than adjacent corridors and saved the average commuter 12–22 minutes per trip. The HOV system in Houston is promoted by METRO and the Texas DOT as conserving fuel and improving air quality in the region. It does that by reducing the levels of congestion, number of vehicles, and idling time of vehicles along these key commuter corridors. METRO converted the HOV lanes to HOT lanes, allowing single-occupant vehicles to use the lanes for a toll only during non-peak and non-congested hours.
Where can I learn more?
Managed Lanes and High-Occupancy Vehicle Facilities is a web page of the Federal Highway Administration’s (FHWA) Freeway Management Program that includes legislation and guidance, studies, an inventory of facilities, and other resources.
Travel Demand Management Publications and Reference Materials is FHWA’s library of resources addressing demand-side strategies to relieve congestion.
Boriboonsomsin K, Barth M. A microscopic approach to modeling air quality impacts of HOV lane conversion. Transportation Land Use, Planning, and Air Quality 2008;338-344.
Center for Environmental Research and Technology (CERT). Modeling the Effectiveness of High Occupancy Vehicle (HOV) Lanes at Improving Air Quality. Riverside, CA: University of California Riverside, CERT; 2006.
Federal Highway Administration (FHWA) Office of Operations. A Review of HOV Lane Performance and Policy Options in the United States. Prepared for the HOV-Pooled Fund Study and the FHWA by Booz Allen Hamilton Inc. and HNTB; 2008.
Fenno, DW, Benz, RJ, Vickich, MJ, Theiss, L. Quantification of Incident and Non-incident Travel Time Savings for Barrier-Separated High-Occupancy Vehicle (HOV) Lanes in Houston, Texas. Austin, TX: Texas Transportation Institute. FHWA/TX-05/0-4740-1; 2005.
Shewmake S. Can carpooling clear the road and clean the air?: Evidence from the literature on the impact of HOV lanes on VMT and air pollution. Journal of Planning Literature 2012;27(4):363–74.
State of Utah, Office of Legislative Auditor General. A Limited Review of HOV Lanes. Report Number ILR2010-C. 2010.
U.S. EPA. Transportation Control Measure Information Documents: High-occupancy vehicle lanes. EPA400-R-92-006; 1992.