A cloverleaf interchange is a two-level interchange in which left turns (reverse directions in left-driving regions), are handled by ramp roads (US: ramps, UK: slip roads). To go left (in right-hand traffic), vehicles first continue as one road passes over or under the other, then exit right onto a one-way three-fourths loop ramp (270°) and merge onto the intersecting road. The objective of a cloverleaf is to allow two highways to cross without the need for any traffic to be stopped by red lights, even for left and right turns.