Superstreet

A superstreet is a type of road intersection that is a variation of the Michigan left. In this configuration, in contrast to the Michigan left, traffic on the minor road is not permitted to proceed straight across the major road or highway. Drivers on the minor road wishing to turn left or go straight must turn right onto the major road, then, a short distance away, queue (wait) into a designated U-turn (or crossover) lane in the median. When traffic clears, they complete the U-turn and then either go straight or make a right turn when they intersect the other half of the minor road.

The superstreet typically requires four traffic light-controlled intersections, and most traffic must pass through two of them, but each light has only two phases, greatly increasing average traffic flow; there is no need for numerous left-turn phases where most traffic is waiting for only a few cars to clear the intersection. Turning movements on roads with lower cross-traffic volumes may be controlled with stop or yield signs for turning traffic rather than with signals.

Variations

A (standard) RCUT, in contrast to a Michigan left, typically allows left turns from the major road to minor roads. A variation, designated by the US Federal Highway Administration (FHWA) as a basic RCUT, prohibits such turns, restricting movements to right-in/right-outs and median U-turns only.) When the median is relatively narrow, a "bulb-out" or "loon" protrudes from the roadway, opposite from the median crossover, to accommodate a U-turn by a long vehicle, such as a tractor trailer.