Contraflow lane
（重定向自Contraflow）
In transport engineering nomenclature, a counterflow lane or contraflow lane is a lane in which traffic flows in the opposite direction of the surrounding lanes.
Contraflow lanes are often used for bicycles or bus rapid transit on what are otherwise one-way streets. In a sample configuration for buses, a street might have four lanes: the outermost lanes are reserved for buses in both directions, while the center two lanes are available for general traffic in only one direction. Thus, the street functions as two-way for buses, but one-way for all other vehicles.