Speed limit enforcement is the action taken by appropriately empowered authorities to check that
road vehicles are complying with the
speed limit in force on roads and highways. Methods used include roadside
speed traps set up and operated by the police and automated roadside 'speed camera' systems which may incorporate the use of an
automatic number plate recognition system. Traditionally, the police would have used
stopwatches to measure the time taken for a vehicle to cover a known distance, but more recently, they have had
speed guns and automated
in-vehicle systems at their disposal.