Intersection - Turn Lanes (Unsignalised)

Dedicated turn lanes allow vehicles to slow down to turn without effecting the flow of through traffic. This reduces the risk of rear-end crashes.

Unsignalised intersections turn lanes also provide a safe place for turning drivers to wait for a gap in the opposing traffic. This reduces the risk of a crash between the turning vehicle and opposing through vehicles.

Cross-traffic turn lanes sheltered by a median provide better separation from the opposing traffic stream but turn lanes can be also created with line marking. Sometimes the road can be made wider to fit the turn lane by sealing the shoulder or by taking parking space. Sometimes road carriageway widening is required.

  • Reduced rear-end and sideswipe crashes.
  • Reduced loss of control while turning crashes.
  • Improved traffic flow.
  • Increased intersection capacity.
  • Painted turn lanes must be clearly delineated and have good sight distance.
  • Turn lanes should be long enough to allow a vehicle time to stop within it (clear of through traffic).
  • If a turn lane is too long, through drivers may enter the lane by mistake.
  • Signs at the start of the turning lane may help prevent this.
  • Installing turn lanes can increase the width of the intersection and cause problems for pedestrians trying to cross. One solution is to provide a pedestrian refuge island in the median.

Benefits

  • Reduced rear-end and sideswipe crashes.
  • Reduced loss of control while turning crashes.
  • Improved traffic flow.
  • Increased intersection capacity.

Implementation issues

  • Painted turn lanes must be clearly delineated and have good sight distance.
  • Turn lanes should be long enough to allow a vehicle time to stop within it (clear of through traffic).
  • If a turn lane is too long, through drivers may enter the lane by mistake.
  • Signs at the start of the turning lane may help prevent this.
  • Installing turn lanes can increase the width of the intersection and cause problems for pedestrians trying to cross. One solution is to provide a pedestrian refuge island in the median.

Did you know?

Just a small reduction in vehicle speeds can dramatically increase the chance of a child surviving a collision.

Tell me more

Latest Case Studies

See practical examples of how deaths and serious injuries have been prevented.

Read more

Related Images

Treatment Summary

Costs
Low to medium
Treatment life
5 years - 10 years
Effectiveness
10-25%

References