The public utilities commission is hereby vested with the power and jurisdiction to supervise and regulate public utilities and railroads, to require all public utilities to furnish their products and render all services exacted by the commission or by law, and to promulgate and enforce all orders relating to the protection, welfare, and safety of railroad employees and the traveling public, including the apportionment between railroads and the state and its political subdivisions of the cost of constructing protective devices at railroad grade crossings.