City of Seattle 72-Hour On-Street Parking Ordinance

Regardless of whether or not there is any sign posted, the City's Traffic Code does not allow a vehicle to be parked on a city street for longer than 72 hours.  Move your vehicle off the blockface at least once every 72 hours.  If you are going on vacation, find off street parking or leave your keys with a trusted neighbor to check your vehicle and move it as needed.  

Because parking restrictions on any street can change with 24-hour notice for such things as emergency utility work, cleaning or a special event, people should check for temporary signage every day. Vehicles must be moved by the time indicated or drivers may receive a citation and their vehicle may be towed and impounded.