Built-up area (Highway Code)

A 30 mph speed limit reminder road sign. Used when there is insufficient street lighting for a road to legally have an automatic 30 mph speed limit.

In the UK Highway Code for England, Scotland and Northern Ireland, a built-up area is a settled area in which the speed limit of a road is automatically 30 mph (48 km/h). In Wales it's 20 mph (32 km/h). These roads are known as 'restricted roads' and are identified by the presence of street lights.