(a) Whenever it is necessary for the department, a county, or a municipality to perform any maintenance in regard to a grade separation structure, protective devices, or grade crossing, responsibility for which is imposed on such department, county, or municipality by this part, and the regulation and control of railroad traffic is necessary for the performance of such maintenance, it shall be the duty of the railroad or railroads involved, after receiving notice, to assist the department, county, or municipality by providing reasonable regulation and control of railroad traffic, having due regard to the needs of such traffic and to the public welfare.

(b) Whenever it is necessary for a railroad to perform any maintenance in regard to a grade separation structure, protective devices, or grade crossing, responsibility for which is imposed on such railroad by this part, and the regulation and control of pedestrian and vehicular traffic is necessary for the performance of such maintenance, it shall be the duty of the department, the county, or the municipality, after having received notice, to assist the railroad by providing reasonable regulation and control of pedestrian and vehicular traffic, having due regard to the needs of such traffic and to the public welfare.