Vehicle inspection is a procedure mandated by national or subnational governments in many countries, in which a vehicle is inspected to ensure that it conforms to regulations governing safety, emissions, or both. Inspection can be required at various times, e.g., periodically or on transfer of title to a vehicle. If required periodically, it is often termed periodic motor vehicle inspection; typical intervals are every two years and every year. When a vehicle passes inspection, often a sticker (inspection decal or inspection sticker) is placed on the vehicle's windshield or registration plate to simplify later controls, but in some countries such a Netherlands since 2008 is not necessary anymore. Inspection stations are places to drive inside to see if a vehicle passes inspection once a vehicle is due for inspection. Most US inspection decals/stickers display the month's number and the year.
In some jurisdictions, proof of inspection is required before a vehicle license or license plate can be issued or renewed. In others, once a vehicle passes inspection, an inspection decal is attached to the windshield or registration plate, and police can enforce the inspection law by seeing whether the vehicle displays an up-to-date decal.
There is some controversy over whether periodically inspecting motor vehicles is a cost-effective way to improve road traffic safety.
In Brazil inspections are performed by private companies designated by the cities. Annual inspection is mandatory for all diesel vehicles; all natural gas, gasoline and alcohol vehicles except for new vehicles registered in the current year; all motorcycles and motorbikes, independent of year of fabrication (two-stroke engines are exempt).
After passing inspection the driver is issued an electronic stamp ('selo eletrônico') associated to the license plate of the vehicle. In São Paulo, traffic cameras identify vehicles that did not get their annual inspection and issue tickets. Inspection costs around R$40,00.
Emission testing programs in Canada include AirCare in the Lower Mainland of British Columbia and Ontario's Drive Clean in southern Ontario only.