Carpool / High-Occupancy Vehicle (HOV) Lanes
A high-occupancy vehicle lane is a restricted traffic lane reserved for the exclusive use of vehicles with a driver and one or more passengers, including carpools, vanpools, and transit buses.
These restrictions may be only imposed during at peak travel times or may apply at all times.
Carpool lanes are special freeway lanes used only for carpools, buses, motorcycles, or low-emission vehicles.
The pavement in this lane is marked with a diamond symbol and the words “Carpool Lane.”
These lanes are also known as high-occupancy vehicle (HOV) lanes.
Do not cross over double parallel lines to enter or exit any carpool lane except at designated entry or exit places.
Motorcyclists are allowed to use carpool/HOV lanes, unless otherwise posted.
A high-occupancy vehicle lane (also known as an HOV lane, carpool lane, diamond lane, 2+ lane, and transit lane or T2 or T3 lanes) is a restricted traffic lane reserved for the exclusive use of vehicles with a driver and one or more passengers, including carpools, van-pools, and transit buses.
The introduction of HOV lanes in the United States progressed slowly during the 1970s and early 1980s. Major growth occurred from the mid-1980s to the late 1990s. The first freeway HOV lane in the United States was implemented in the Henry G. Shirley Memorial Highway in Northern Virginia, between Washington, DC, and the Capital Beltway, and was opened in 1969 as a bus-only lane.The busway was opened in December 1973 to carpools with four or more occupants, becoming the first instance in which buses and carpools officially shared a HOV lane over a considerable distance.
Introduction of HOV Lanes in the US
In 2005, the two lanes of this HOV 3+ facility carried during the morning peak hour (6:30 am to 9:30 am) a total of 31,700 people in 8,600 vehicles (3.7 persons/veh), while the three or four general-purpose lanes carried 23,500 people in 21,300 vehicles (1.1 persons/veh). Average travel time in the HOV facility was 29 minutes, and 64 minutes in the general traffic lanes. As of 2012, the I-95/I-395 HOV facility is 30 mi (48 km) long and extends from Washington, D.C., to Dumfries, Virginia, and has two reversible lanes separated from the regular lanes by barriers, with access through elevated on- and off-ramps. Three or more people in a vehicle (HOV 3+) are required to travel on the facility during rush hours on weekdays.
The second freeway HOV facility was the contraflow bus lane on the Lincoln Tunnel Approach and Helix in Hudson County, New Jersey, opened in 1970. According to the Federal Highway Administration (FHWA), the Lincoln Tunnel XBL is the country’s HOV facility with the highest number of peak hour persons among HOV facilities with utilization data available, with 23,500 persons in the morning peak, and 62,000 passengers during the four-hour morning peak.
The first permanent HOV facility in California was the bypass lane at the San Francisco–Oakland Bay Bridge toll plaza, opened to the public in April 1970. The El Monte Busway (I-10 / San Bernardino Freeway) in Los Angeles was initially only available for buses when it opened in 1973. Three-person carpools were allowed to use the bus lane for three months in 1974 due to a strike by bus operators, and then permanently at a 3+ HOV from 1976. It is one of the most efficient HOV facilities in North America and is currently being converted into a high-occupancy toll lane operation to allow low-occupancy vehicles to bid for excess capacity on the lane in the Metro ExpressLanes project.