Speed limit checker
Pick a road and a vehicle. The limits people get wrong are almost always the towing ones.
National speed limit
60 mph
One carriageway, traffic in both directions.
A limit is a ceiling, not a target
The Highway Code is explicit that the limit is the absolute maximum, and that it does not mean it is safe to drive at that speed. A narrow rural lane with a 60 mph limit is almost never a 60 mph road.
Signs always override the national limit. Where a lower limit applies you will see terminal signs and repeaters.