A slip lane is a road at a junction that allows people to change roads without actually entering an intersection.[1]

Illustration (left-hand traffic): the blue vehicle in the slip lane must give way to the green and red vehicles even though the latter is at a give way control.

Some intersections controlled by lights offer a slip lane that allows cars to bypass the lights when turning. This helps ease congestion and improves journey times, as people turning don’t have to stop at the light and can continue at the same speed.[2] There are two types of slip lanes at intersections: slip lanes that end and require traffic to merge in order to join the main road, and slip roads that continue onto the main road as another traffic lane.

Slip lane rulesEdit

In Australia, before entering a slip road, drivers must look to ensure that their blind spots are clear of other motorists, cyclists, and pedestrians. Then drivers must give way to any pedestrians crossing the slip road. Before joining the main road from a slip road, drivers must give way to all other traffic even when that traffic is faced with a give-way or other traffic controls.[3]


In countries such as the UK where partial conflicts between pedestrians and vehicular traffic is not permitted, slip lanes can be used as part of a 'walk with traffic' facility. Normally, pedestrian signals in the UK will operate on a full pedestrian stage, where all traffic is held at red, and all pedestrian crossings are given a green signal. With a slip lane, pedestrians can cross to the triangular island during the vehicle red phase, then cross the road while the traffic from their approach has a green.[4]


The organisation Strong Towns argues that slip lanes only exist to prioritise the speed of motor traffic and calls for the removal of slip lanes on local streets.[5]

When poorly designed, slip lanes can be a dangerous design element. For reasons of urban design and pedestrian safety, many road-controlling authorities are actively removing them in urban and suburban settings.[6][7] Slip lanes may need to be removed if considerations such as pedestrian safety grow to a point where they override the desire to facilitate free passage for cars.[8][9]

To minimise risks of collision, slip lanes can be shaped to enter the traffic flow at a higher angle than the 45 degrees shown in the sketch. Such lanes are called high entry angle slip lanes.[10]

See alsoEdit


  1. ^ "Pedestrians crossing slip lanes" (PDF). Main Roads Western Australia. September 2002. Retrieved 8 November 2015.
  2. ^ https://www.strongtowns.org/journal/2019/11/5/slip-lanes-would-never-exist-if-we-prioritized-safety-over-speed
  3. ^ http://www.cota-act.org.au/Livedrive/road_rules.html
  4. ^ Traffic signs manual. Chapter 6, Traffic control. Great Britain. Department for Transport, Northern Ireland. Department for Infrastructure, Scotland. Scottish Government, Wales. Welsh Government. London. 2019. ISBN 978-0-11-553744-8. OCLC 1134444798.CS1 maint: others (link)
  5. ^ "Slip Lanes Would Never Exist if We Prioritized Safety Over Speed". Strong Towns. Retrieved 2022-01-05.
  6. ^ "Well Designed Right–Turn Slip Lanes". Federal Highway Administration.
  7. ^ "Cities Are Replacing Dangerous Slip Lanes With Space for People". Streetsblog. July 2018. Retrieved 4 June 2019.
  8. ^ "City Road Draft Master Plan" (PDF). Melbourne City Council. July 2015. Retrieved 8 November 2015.
  9. ^ "Slip Lanes be gone". Matt L. 2 October 2015. Retrieved 8 November 2015.
  10. ^ "Guidelines for the signing and layout of slip lanes" (PDF). NZ Transport Agency. November 1993. Retrieved 9 May 2017.