A circular sign with a red border containing the number '50' indicates a mandatory upper speed ceiling of 50 miles per hour.
It is frequently deployed on rural single carriageways with sharp bends, high collision rates, or through motorway smart roadworks zones.
What this sign means
The legal maximum speed for all vehicles on this stretch of road is 50 mph.
It overrides higher national speed limits on single or dual carriageways.
- Red circular border around numeral 50.
- Mandatory legal maximum speed limit.
- Deployed on high-risk rural roads, dual carriageways, and roadworks.
What to do when you see it
Gently decelerate to 50 mph or below prior to reaching the sign position.
Maintain careful speed monitoring, especially when driving down declines or through average speed camera corridors.
How this sign is tested
Theory test questions cover overall stopping distances and speed limit enforcement signs.
Questions check candidate understanding of temporary roadworks speed limit signs.
Common mistakes
Assuming a 50 mph roadworks sign on a motorway is advisory rather than mandatory (it is legally binding).
Failing to calculate increased stopping distance requirements when travelling at 50 mph.
Test yourself on this one
Road and traffic signs is the biggest category in the question bank with 102 questions, and signs turn up inside other categories too. Work through them free, no sign-up needed.
Practise road sign questionsFrequently asked questions
What is the average stopping distance at 50 mph?
The total average stopping distance at 50 mph is 53 metres (175 feet).
Are roadworks 50 mph signs mandatory?
Yes, signs enclosed in red circles set legally binding maximum speed limits.
How are 50 mph speed limits enforced on motorways?
They are enforced using average speed cameras and overhead digital gantries.