The commissioners having charge of movable span bridges shall cause to be posted in each commissioner’s or operator’s shelter rules and regulations governing the operation of the structure and all parts appertaining thereto, and shall see that every operator complies with such regulations. Such regulations shall be in accordance with the specifications of the state highway department as applying to movable bridges and with such other regulations in regard to signals, lights, etc., as may be prescribed by the war department of the United States government or as may be otherwise existent for the control of navigation.