HOV lane

US /ˌeɪtʃ.oʊˈviː leɪn/
UK /ˌeɪtʃ.oʊˈviː leɪn/
"HOV lane" picture
1.

a lane on a highway reserved for vehicles carrying a specified minimum number of passengers, typically two or more, to encourage carpooling and reduce traffic congestion

:
During rush hour, the HOV lane moves much faster than the regular lanes.
You need at least two people in the car to use the HOV lane.