Any railroad company whose right of way, or whose track or roadbed upon such right of way, passes through any canyon, pass, or defile shall not prevent any other railroad company from the use and occupancy of said canyon, pass, or defile for the purposes of its road, in common with the road first located, or the crossing of other railroads at grade; and the location of such right of way through any canyon, pass, or defile shall not cause the disuse of any tramway, wagon road, or other public highway now located therein, nor prevent the location through the same of any such tramway, wagon road, or highway where such tramway, wagon road, or highway may be necessary for the public accommodation; and where any change in the location of such tramway, wagon road, or highway is necessary to permit the passage of such railroad through any canyon, pass, or defile, said railroad company shall, before entering upon the ground occupied by such tramway, wagon road, or highway, cause the same to be reconstructed at its own expense in the most favorable location, and in as perfect a manner as the original road or tramway: Provided, That such expenses shall be equitably divided between any number of railroad companies occupying and using the same canyon, pass, or defile, and that where the space is limited the United States district court shall require the road first constructed to allow any other railroad or tramway to pass over its track or tracks through such canyon, pass, or defile on such equitable basis as the said court may prescribe; and all shippers shall be entitled to equal accommodations as to the movement of their freight and without discrimination in favor of any person or corporation: Provided, That nothing herein shall be construed as depriving Congress of the right to regulate the charges for freight, passengers and wharfage.