The entire cost, including costs of culverts, headers, filling, engineering, attorney’s fees, labor, and material, of the improvement shall be apportioned as follows: (1) The abutting real estate owners shall pay all the costs of paving or improving streets and street intersections, the cost of the intersection to be pro-rated against all of the property abutting the street; (2) When a railway occupies a portion of the street or alley, the owner thereof shall pay in the proportion that the area of the space occupied by its roadbed bears to the total area of the street, alley or portion thereof to be improved.