Safe speeds
The difference between 20mph zones and 20mph limits
How and why traffic calming measures are used in certain areas
20mph zones
A 20mph (miles per hour) zone sets the maximum speed to 20mph. It also uses physical traffic calming features to help drivers and riders maintain a safe speed.
Traffic calming features can include:
- Speed humps or raised tables. Theses are raised sections of road that slow vehicles.
- Build‑outs, chicanes or narrowed lanes. These are road layouts that reduce width or add bends to slow traffic.
- Raised junctions or entry treatments. These are raised entrances that signal a slower‑speed area.
20mph zones have signs to indicate when you are entering and leaving a zone.
They are best on streets that do not have a high proportion of larger vehicles.
20mph limits
A 20mph limit sets the maximum legal speed to 20mph on a road or group of roads.
These areas have 20mph signs with repeater signs along the street.
20mph limits suit residential streets, village roads, and urban areas. Lower speeds are more appropriate for these areas, but traffic calming features are not practicable. This could be because:
- The roads need to cater for larger vehicles and traffic calming features would make this difficult
- Traffic calming would cause discomfort to bus passengers
- Traffic calming would cause unwanted noise
