Gatso

These use a powerful flash, to show the rear of the vehicle, its registration plate, and calibration lines on the road (in many jurisdictions).

It can be a common misconception by drivers that the police do not use the distance travelled between the secondary check marks before issuing a notice in the post.

The police can make mistakes, but the combination of radar reading and secondary check marks is a robust case for prosecution.

[citation needed] The Department of Transport took an interest, and sponsored a trial involving the Home Office and the Metropolitan Police.

They had to be marked, made visible, located in places with a history of serious accidents, and where there was evidence of a speeding problem, or where there was a local community concern.

It is still recommended that cameras be made visible and roads with fixed ones, clearly signed, but they can now be placed at any location, regardless of its crash history.

The Specific Road Safety Grant was cancelled in 2010 by the Department for Transport following the 2010 UK Government's Comprehensive Spending Review.

Concerns have been raised that the powerful flash used when the cameras trigger may dazzle drivers travelling in the opposite direction.

The company was later formed to market the devices as police speed enforcement tools and remains largely a family concern with two Gatsonides among the five directors.

The company's products, particularly the "Gatsometer 24", have achieved such a high level of market penetration in the UK and some European countries that the term "Gatso" became synonymous with "speed camera" across a significant proportion of Europe.