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Cardiff Council

Box junctions

Yellow box junctions are placed at busy junctions to aid the flow of traffic through the junction. They can also be placed to keep a road space free to ensure emergency services have a clear exit from fire stations and hospitals. 

Recognising a box junction

Yellow box junctions are indicated by yellow crisscross lines painted on the carriageway:

Yellow box junction
They can be found at road junctions and at some roundabouts and there are no requirements for yellow box junctions to be accompanied by signs or a Traffic Regulation Order.

Using a box junction

The rules of box junctions can be found in the Highway Code (174)

You may enter a yellow box junction when your exit is clear and there is enough space on the other side of the junction for your vehicle to clear the box completely without stopping. You can stop in a yellow box junction when turning right if you are prevented from turning by oncoming traffic, or by other vehicles waiting to turn right.

Top tips to avoid a Penalty Charge Notice (PCN)

We issue PCNs for a failure to comply with the rules of box junctions. 

  • Check your exit is clear. If you simply follow the vehicle in front of you without doing so it may stop and prevent you from fully crossing the junction.
  • Just because a traffic light is green this does not mean the rules of box junctions do not apply.
  • Don't let other drivers pressure you into entering the box when a clear exit is not available

© 2022 Cardiff Council