A high-occupancy vehicle lane is a restricted traffic lane reserved for the exclusive use of vehicles with a driver and at least one passenger, including carpools, vanpools, and transit buses. These restrictions may be only imposed during peak travel times or may apply at all times. There are different types of lanes: temporary or permanent lanes with concrete barriers, two-directional or reversible lanes, and exclusive, concurrent, or contraflow lanes working in peak periods.
A high-occupancy vehicle lane on Interstate 5 in Seattle
The first HOV freeway, which opened in 1969, was on Shirley Highway in Northern Virginia; as of 2012, the I-95/I-395 HOV facility operates as a two-lane barrier-separated reversible HOV 3+ facility (center lanes) with access through elevated on- and off-ramps.
For 50 years, from 1970 to 2020, the California Department of Transportation preferred to use the term "carpool", as seen on I-405 in Los Angeles, as opposed to "HOV".
The I-495 Capital Beltway in the Washington D.C. Metropolitan Area. The facility is located in the median, has two HOV lanes in each direction with elevated on/off ramp access with a total of 224.0 mi (360.5 km) of lanes.
The Capital Beltway is a 64-mile (103 km) auxiliary Interstate Highway in the Washington metropolitan area that surrounds Washington, D.C., the capital of the United States, and its inner suburbs in adjacent Maryland and Virginia. It is the basis of the phrase "inside the Beltway", used when referring to issues dealing with US federal government and politics. The highway is signed as Interstate 495 (I-495) for its entire length, and its southern and eastern half runs concurrently with I-95.
The Woodrow Wilson Bridge carrying I-95/I-495 over the Potomac River between Alexandria, Virginia, and Oxon Hill, Maryland, April 2007
"Maryland Welcomes You" sign on the Outer Loop over the Woodrow Wilson Bridge
I-95/I-495 and I-295 interchange in Maryland seen from the air above the Potomac River, 2012