1.    A public highway-railroad crossing at grade shall be constructed of a grade of earth on one or both sides of the railroad track, as the location may require, for the entire width of the highway grade but in no case less than twenty feet [6.10 meters] in width, the middle point of which shall be as nearly as practicable at the middle point of the highway and such grade shall be of such slope as shall be necessary for the safety and convenience of the traveling public.

2.    Firmly fastened planks, concrete, asphalt, or other suitable material for highway construction shall be used on and for the full length of the ties used in the roadbed of such railway where such crossing occurs. The highway material next inside of the rail shall not be more than two and one-half inches [6.35 centimeters] from the inside surface of such rail. The highway material used in the crossing shall not be less than     three inches [7.62 centimeters] in thickness, and shall be laid so that the upper surface of the highway material shall be on a level with the upper surface of the rail.

3.    At such time as tracks through a railroad crossing are raised or otherwise altered by the railroad, the railroad shall, unless otherwise ordered by the commission, adjust and restore the crossing and the highway approaches, surfaces, and grades as shall be necessary for the safety and convenience of the traveling public. At such time as a public highway at a railroad crossing is altered by the road authority, the road authority at its expense shall adjust and restore the crossing and the highway approaches, surfaces, and grades as shall be necessary for the safety and convenience of the traveling public.

4.    It shall be the duty of the railroad to maintain all railroad crossings in a safe and convenient condition for the traveling public. Such responsibility for maintenance shall be limited to that portion of the crossing lying between the tracks and for two feet [.61 meters] beyond the ends of the crossties on each side of the crossing.