A 30 percent growth over the last year in mobile speed camera use in the UK has generated controversy. Fixed speed camera units are marked bright yellow and may only be placed in locations with a significant crash history. Mobile units, on the contrary, are often hidden in vans or on motorcycles and their locations aren't strictly regulated.

Drivers have begun using GPS locators to warn of upcoming fixed camera sites. Companies such as Chevrolet, Vauxhall and MG have begun offering them as optional or standard equipment on new cars. But mobile sites are not always detected by GPS.

Some believe the country has reached the saturation point with 6,000 fixed camera sites. Cyclops, a UK company which manufactures GPS locators, estimates at the current rate there could be as many mobile sites as fixed units by the end of the year.

Motorist advocates argue the reason for this expansion is the US $212 million in yearly revenue generated from camera fines.

Key Statistic:
There were 3,499 cameras hidden in police cars, vans and motorcycles last year, compared with 2,601 in 2003. About 1.8 million £60 fixed-penalty notices were issued in England and Wales in the financial year 2003-2004 - up from 260,000 three years earlier.