Automated speed enforcement (speed cameras)

Automated speed enforcement uses roadside cameras to measure how fast a vehicle is going — with radar, lidar, in-road loops, or by timing a car between two points for an "average speed" check — and then automatically mails a fine to the registered owner. Detection, evidence and penalty run end to end with no officer at the roadside: a machine writes the ticket. That makes it distinct from ANPR, which reads number plates for access, tolling or parking; here the plate is only how the fine finds an owner, and the speed reading is the offence.

Cities deploy it mostly for road safety, and the measured gains can be large. New York's Vision Zero school-zone cameras report speeding down 94% at fixed sites, and a peer-reviewed study of Toronto's programme found the share of speeding vehicles fell 45%.

The honest trouble is rarely the technology; it is money and politics. Critics call the cameras a "tax grab," so who profits matters: San Francisco's law bans paying the vendor per ticket, while other contracts share the revenue. Fines often go uncollected — Washington, D.C. cannot bill out-of-state drivers who ignore the notice — and a higher tier of government can simply switch a working system off, as Ontario did to Toronto in 2025 and as Quebec never let Montreal turn on.