The Washington State Department of Transportation (WSDOT) owns and operates 47 safety rest areas across the state, most open to the public 24 hours a day.  Features of the safety rest areas include motor vehicle parking, commercial truck and recreational vehicle parking, Americans with Disabilities Act–accessible restrooms, drinking water, traveler information, vending machines, picnic areas, public telephones, and more.  WSDOT estimates more than 24 million visitors use the state's safety rest areas annually.

It is unlawful for any person to park a vehicle, which include trailers, campers, and motorcycles, that is not disabled for more than eight hours within a 24-hour period at a state-owned safety rest area.  Disabled vehicles may be parked in safety rest areas up to forty-eight hours before they are subject to mandatory impoundment.  Commercial vehicles may be parked at safety rest areas up to an hour beyond federally mandated rest periods.  WSDOT may designate zones within a safety rest area with shorter parking time limits to maximize efficiency and safety. 

The Washington State Patrol (WSP) is charged with enforcing these safety rest area parking limitations to the maximum extent practicable.  The WSP, under its authority to remove vehicles from the highway system including safety rest areas, may remove the vehicles directly through contracted towing operators appointed by the WSP and called on a rotational or other basis.  WSDOT must post appropriate signage at all safety rest areas regarding parking time limits and impoundment.  The signage must include the times a vehicle may be impounded as an unauthorized vehicle, and the name, telephone number, and address of the towing firm where the vehicle may be redeemed.

For the purposes of statutes related to towing and impoundment, "unauthorized vehicle" is defined as a vehicle that is subject to impoundment after being left unattended in public or private locations for indicated periods of time.

Vehicles that are not disabled are subject to impoundment for violating safety rest area parking limits, in addition to disabled vehicles.

Signage regarding safety rest area parking time limits is required to be posted near each entrance, and on the property in a clearly conspicuous and visible location to all who park on the property.  The signage must indicate a phone number for contacting the law enforcement agency, or WSDOT to locate the impounded vehicle.

The definition of unauthorized vehicle related to towing and impoundment is amended to include vehicles subject to impoundment after being left unattended, and in violation of safety rest area parking time limits.