High-occupancy Vehicle Lane

A high-occupancy vehicle lane (also HOV lane, carpool lane, diamond lane, and transit lane or T2 or T3 lanes in Australia and New Zealand) is a restricted traffic lane reserved at peak travel times or longer for exclusive use of vehicles with a driver and one or more passengers, including carpools, vanpools and transit buses. The normal minimum occupancy level is 2 or 3 occupants. Many jurisdictions exempt other vehicles, including motorcycles, charter buses, emergency and law enforcement vehicles, low emission and other green vehicles, and/or single-occupancy vehicles paying a toll. HOV lanes are normally created to increase higher average vehicle occupancy and person throughput with the goal of reducing traffic congestion and air pollution although their effectiveness is questionable.

Regional and corporate sponsored vanpools, carpools, and rideshare communities give commuters a way to increase occupancy. For places without such services, online rideshare communities can serve similar purpose. Slugging lines are common in some places, where solo drivers pick up a passenger to share the ride and allow use of the HOV lane. High occupancy toll lanes (HOT lanes) have been introduced in the United States to allow solo driver vehicles to use the lane on payment of a variable fee which usually varies with demand. Motorcycles are permitted in the HOV lanes for safety reasons.