The estimated cost of right-of-way is $735,000,000 for all rural sections to be improved, an average of $23,200 per mile, and about 12 percent of the cost of the rural sections. For all urban sections the estimated cost totaling $1,667,000,000 averages $517,600 per mile and is more than 31 percent of the cost of the urban sections.
The estimated cost of all bridges to be built or altered on the system is $2,888,900,000. This amounts to about one-fourth of the estimated cost of all work required. Of the total bridge cost, $1,687,200,000, or 58 percent, is for structures in urban areas. New structures to be built on relocated sections of the system represent 72 percent of the total bridge cost.
The estimated cost of all tunnel work proposed is $106,200,000. Of this amount, $82,400,000 is for the enlargement of existing tunnels, of inadequate width. The cost of the five new tunnels to be constructed is estimated at $23,800,000. Of the total cost of tunnels, $46,600,000 is for tunnels in rural areas and $59,600,000 for tunnels in urban areas.
Combined, the estimated costs of right-of-way, bridges, and tunnels amount to $5,397,100,000, which is 48 percent of the estimated total costs. In rural areas, the cost of these elements of the proposed improvements is $1,983,300,000, about one-third of the total rural cost; in urban areas it is $3,413,800,000, which is nearly two-thirds of the total urban cost.
Costs of road construction
After deduction of the costs of right-of-way, bridges, and tunnels, the remainder of the estimated cost, which is the net cost of all road construction, is $5,869,300,000, which represents an average cost of $168,400 per mile for the mileage to be improved. The corresponding cost of road construction work to be executed on rural sections of the system is $3,989,700,000, an average of $126,100 per mile; and for road work only in urban areas the cost is $1,879,600,000, an average of $583.600 per mile.
COST PER MILE
Including all costs, the $11,266,400,000 cost of the work proposed represents an average of $323,180 per mile for the mileage to be improved, and $303,190 per mile for the entire mileage.
Rural and urban costs per mile
The similar total cost for rural sections of the system, $5,973,000,000, represents an average of $188,800 per mile for the mileage to be improved, and $177,600 per mile for the entire mileage, including the 1,998 miles that are adequate in their present condition.
On the same basis, the total cost for urban sections, $5,293,400,000, represents an average of $1,643,400 per mile for the mileage to be improved and $1,503,400 per mile for the entire mileage, including the 300 miles already adequate.
Ratio of rural and urban costs
The cost of the actual work required, on a per-mile basis, appears from the above figures to be about 8.7 times as great for the urban as for the rural sections of the system. On the basis of the total mileage of the system, including the mileage on which no work is required, the per-mile costs of urban and rural work are in the ratio of about 8.5 to 1.
