Whenever any railroad and state highway or part thereof shall cross each other at the same level and, in the opinion of the State Highway Commission, such crossing is dangerous to public safety or traffic is unreasonably impeded thereby and such crossing should be removed, the State Highway Commission may order such crossing eliminated either by having the State Highway Department carry such state highway under or over the tracks of such railroad.

The plans covering such proposed changes may be made either by the director of the State Highway Department, subject to the approval of the highway commission or the railroad company affected, but shall in either event be approved by both the highway commission and the railroad company before contract is awarded; but such provision shall not be used to unreasonably delay the construction of any proposed structure. When plans have been approved, such proposed work shall be advertised and contract awarded as elsewhere provided in this chapter for the advertising and awarding of contracts. Joint supervision of construction may be had by both the State Highway Department and the railroad company. The state highway commission and the railroad company shall pay equal parts of the cost of any underpass or overpass across the right-of-way of the railroad company. Such work shall be so planned and prosecuted as to allow the safe and regular operations of trains at every stage of the work.

Appeals from decisions or determinations of the State Highway Commission may be made by any party affected under this section, and the procedure for such appeal shall be the same as is provided by law for appeals from decisions and determinations of the boards of supervisors.