Traffic enforcement camera
A traffic enforcement camera is a camera which may be mounted beside or over a road or installed in an enforcement vehicle to detect motoring offenses, including speeding, vehicles going through a red traffic light, vehicles going through a toll booth without paying, unauthorized use of a bus lane, or for recording vehicles inside a congestion charge area. It may be linked to an automated ticketing system.
A Gatso speed camera. The camera's lens is visible at top left, while the large flash, used for illuminating number plates and calibration lines on the road when taking photographs, is visible on the bottom right.
A speed camera in Mong Kok, Hong Kong
A speed camera on the Highway 5 in Joroinen, South Savonia, Finland
Automatic speed enforcement gantry or "Lombada Eletrônica" with ground sensors in Brasília, D.F
Speed limits on road traffic, as used in most countries, set the legal maximum speed at which vehicles may travel on a given stretch of road. Speed limits are generally indicated on a traffic sign reflecting the maximum permitted speed, expressed as kilometres per hour (km/h) or miles per hour (mph) or both. Speed limits are commonly set by the legislative bodies of national or provincial governments and enforced by national or regional police and judicial authorities. Speed limits may also be variable, or in some places nonexistent, such as on most of the Autobahnen in Germany.
A road sign shows maximum and minimum speed limit for different types of vehicle on expressway in China. Speed limit signs are shown in kilometres per hour.
Historic New Hampshire speed limit sign
In 1920 a pastor was fined US$10 for "overspeeding his machine ... at a rate greater than 25 mph (40 km/h) ... in what appeared to be a reckless manner."
Example variable speed limit sign in the United States, in mph