If there's no speed-limit sign, the limit is set by the type of road. These "national" limits are worth memorising.
| Road type | Car / car-derived van |
|---|---|
| Built-up area (street lights) | 30 mph |
| Single carriageway | 60 mph |
| Dual carriageway | 70 mph |
| Motorway | 70 mph |
These are the defaults. A sign always overrides them — for example a 20 mph zone, or a 50 mph limit on a stretch of dual carriageway.
If a road has street lights and no other speed-limit signs, the limit is almost always 30 mph. It's a common theory test question.
Larger vehicles and cars towing a trailer/caravan usually have lower limits. A car towing is limited to 50 mph on single carriageways and 60 mph on dual carriageways and motorways. Goods vehicles also have reduced limits. The test may ask you to spot the right limit for the vehicle described.
Increasingly common near schools, in residential areas and town centres. They're shown with signs and often traffic-calming features. Wales now has a default 20 mph limit on many restricted roads.
Higher speed dramatically increases your stopping distance — doubling your speed roughly quadruples the braking distance. See our stopping distances guide.
