46.61.530
Racing of vehicles on highways — Reckless driving — Exception.

No person or persons may race any motor vehicle or motor vehicles upon any public highway of this state. Any person or persons who wilfully compare or contest relative speeds by operation of one or more motor vehicles shall be guilty of racing, which shall constitute reckless driving under RCW 46.61.500, whether or not such speed is in excess of the maximum speed prescribed by law: PROVIDED HOWEVER, That any comparison or contest of the accuracy with which motor vehicles may be operated in terms of relative speeds not in excess of the posted maximum speed does not constitute racing.