Average-speed monitoring vs spot-speed cameras

Speed monitoring aims to reduce speeding where it causes the most harm. The two main approaches change driver behaviour in different ways.

Spot-speed measurement

A radar, laser or camera system measures speed at a single point. It suits specific hazards — a school crossing, a junction, a sharp bend. Its weakness is well known: drivers brake for the camera and speed up again afterwards.

Average-speed measurement

Number-plate recognition cameras at two or more points record when each vehicle passes. The system calculates average speed over the distance between them. Because drivers must stay within the limit for the whole section, it tends to produce steadier speeds along a corridor.

Virtual speed cameras

AI video analytics can measure vehicle speed from camera footage on new or existing camera networks. This makes it practical to monitor more locations for traffic studies and planning. Where measurements are used for enforcement, the equipment and evidence must meet the enforcing authority's requirements.

Choosing

Use spot measurement for point hazards, average-speed for long risky sections, and camera-based monitoring to understand speeds across a network before deciding where enforcement is needed.

See our AI speed monitoring systems.