Slip lane

This article relates to at-grade intersections. For the British term referring to acceleration lanes at a grade-separated junction, see Interchange (road).

In road design, a slip lane is a road at a junction that allows road users to change roads without actually entering an intersection.[1] Slip lanes are "helpful... for intersections designed for large buses or trucks to physically make a turn in the space allotted, or where the right turn is sharper than a 90 degree turn."[2] Slip lanes may reduce congestion and "t-bone" motor vehicle collisions, but they increase the risk for pedestrians, cyclists and horse riders who cross the slip lane.

Illustration (left-hand traffic): the blue vehicle in the slip lane must normally give way to the green and red vehicles once they are on the major road.

Some intersections that are controlled by traffic light offer a slip lane, which allows users to bypass the lights when they turn. That helps ease congestion and improves journey times, as people who are turning do not have to stop at the light but can continue at the same speed.[3] There are two types of slip lanes at intersections: slip lanes that end and require traffic to merge to join the main road, and slip roads that continue onto the main road as another traffic lane.

  1. ^ "Pedestrians crossing slip lanes" (PDF). Main Roads Western Australia. September 2002. Retrieved 8 November 2015.
  2. ^ Davis, Stephen Lee (5 November 2019). "Slip Lanes Would Never Exist if We Prioritized Safety over Speed". Strong Towns.
  3. ^ Davis, Stephen Lee (5 November 2019). "Slip Lanes Would Never Exist if We Prioritized Safety over Speed". Strong Towns.