One-way pair

A one-way pair is a pair of parallel, usually one-way streets that carry opposite directions of a signed route or major traffic flow, or sometimes opposite directions of a bus or streetcar route.

This is usually done to provide higher capacity by increasing the number of lanes in each direction. It also makes traffic lights on the through route easier to time optimally, because fewer phases are needed at each intersection.

On a one-way pair, traffic usually flows the same way as on a normal divided highway, though occasionally flow is switched.