The word "highways" as used in this act shall include without limitation all state, county and township highways and roads and all highways, streets, avenues, boulevards and alleys in cities and villages, and any place wheresoever situated in this state which is dedicated to the use of public vehicular traffic.

     A public authority having jurisdiction and control over any highway in this state that determines that the safety of persons and property require the installation of the devices provided for in this act at any intersection of that highway with any other highway or at any bridge approach in that highway, may construct, install, operate, and maintain at each such place automatic or mechanically operated barricading devices, which, when giving warning, shall rise from a bed in the highway and become a barrier in the highway.

     Whenever such barricading device shall be constructed, installed, operated or maintained, the public authorities having jurisdiction and control over the highway at any such place shall install and maintain at the side of such highway, immediately adjacent to such device, reflectorized warning signs with the words "automatic barrier" in letters not less than 3 inches high. Whenever such device is located at a railroad intersection, additional reflectorized warning signs, of a design to be prescribed by the state highway commissioner, shall be installed and maintained on both sides thereof at a distance not less than 400 feet therefrom when such intersection is located on a highway where vehicular traffic is permitted to travel at speeds in excess of 30 miles per hour, and not less than 200 feet therefrom when such intersection is located on a highway where vehicular traffic is permitted to travel at speeds not in excess of 30 miles per hour, and such device and warning signs shall be in lieu of all other protection at such intersection. The advance warning signs required by any other law of this state shall also be installed and maintained.

     The public authorities, or the political subdivision of the state, having jurisdiction and control over any highway, in which such device is constructed, installed, operated and maintained, shall bear the expense thereof, unless the parties in interest agree otherwise in writing.