HOV lanes in the U.S.

A high-occupancy vehicle lane (also known as a HOV lane) is a restricted traffic lane reserved at peak hour times or longer for exclusive use of vehicles with a driver and one or more passengers, including carpools, van-pools and transit buses. The normal minimum occupancy level is 2 or 3 occupants.

The introduction of HOV lanes in the U.S. progressed slowly during the 1970s and early 1980s. Major growth occurred from the mid-1980s to the late 1990s. 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.

As of 2005, the two lanes of this HOV 3+ facility were carrying 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 3 or 4 general purpose lanes carried 23,500 people in 21,300 vehicles (1.1 persons/veh). Average travel time in the HOV facility is 29 min while 64 min in the general traffic lanes. Three or more people in a vehicle (HOV 3+) are required to travel on the facility during rush hours on weekdays.