Leftturning

Left-turning, in traffic engineering, refers to the act of steering a vehicle to the driver's left at an intersection or junction. The maneuver typically begins from a lane that allows turning left and ends in the street or road heading in the driver's new direction. Left turns usually require yielding to oncoming traffic and pedestrians, and are regulated by traffic signals, signs, and road markings. In many countries, a protected left turn is provided by a dedicated turn signal (a green arrow) that authorizes the maneuver independently of oncoming traffic. When such protection is not present, drivers may perform a permissive left turn after stopping or waiting for a gap in traffic, depending on local rules. Some jurisdictions allow left turns on red after a complete stop, while others prohibit it.

Design features commonly associated with left turns include dedicated left-turn lanes, two-stage left turns in complex intersections to reduce conflicts, and restrictions in areas with high pedestrian or tram traffic that require special procedures. Safety concerns include collisions with pedestrians crossing the street being turned into, cyclists riding in the turning lane or adjacent bike lane, and opposing traffic conflicts. Providing protected signals, clear signage, and well-designed intersection geometry helps reduce these risks.

In right-hand traffic countries (driving on the right), turning left crosses opposing traffic; in left-hand traffic countries, the crossing is with traffic from the opposite direction as well. The exact rules vary by jurisdiction.