What’s the purpose of road humps, chicanes and narrowings?

Explanation: Traffic-calming measures help to keep vehicle speeds low in congested areas where there are pedestrians and children. A pedestrian is much more likely to survive a collision with a vehicle travelling at 20 mph than they are with a vehicle travelling at 40 mph.

Category: Safety and your vehicle

References: The Official DVSA Guide to Driving: Section 6, Highway Code: Rule 153