20mph zones can be very effective at controlling traffic speeds, reducing the number of accidents that cause injuries and reducing the severity of accidents.
Where are they introduced?
Zones can be introduced on a single road or part of a network of roads. They need to be accompanied by physical traffic calming measures to ensure they are self-enforcing – that is, to make motorists slow down automatically.
20mph zones are often introduced near schools and in residential areas. They make it safer for children to walk and cycle to school.
Typically, 20 mph zones are introduced on roads where:
- A significant number of drivers travel at speeds of approximately 25 mph or higher
- There is a clear aim to reduce speeds to 20 mph or lower
Such zones are particularly effective in reducing accident numbers when part of an area-wide local safety scheme.