Obviously, if the police observe an offence or reasonably expect that the vehicle or occupants have been involved in an offence, the vehicle may be stopped and checked. Otherwise, the police may stop a vehicle at any time to insure that the driver is properly licenced and that the vehicle is roadworthy, properly licenced and insured. Even though it has been ruled a Charter of Rights infringement, police may also operate a roadcheck to stop drinking drivers. The courts have ruled that this infringement is necessary to protect the public.