The department has and exercises throughout the states such police powers and duties as are vested in sheriffs and peace officers generally, and such other powers and duties as are presented by chapter 43.43 RCW and other applicable RCW chapters. The members of the department enforce, throughout the state, laws having statewide application. The individual officer assumes his law enforcement role after a period of rigorous training, and is vested with certain discretion in his contact with alleged law violators in the same degree as are sheriffs and other peace officers. His role also encompasses providing nonlaw enforcement assistance to members of the public within his competence and training, including first aid, traffic direction, aid to stranded motorists, etc.