The report continued, “Construction to the standards recommended will certainly be expensive beyond the common experience in building most of the ordinary existing roads and streets, but the merit of the expenditure is to be judged not by such a comparison but rather by the value of the advantages to be gained in traffic facilitation, in reduced costs of vehicle operations, and in lowered accident rates.”[1]
As noted earlier, the 1958 and 1961 estimates, each totaling $41 billion in cost, formed the basis for the 1961 Act. In compliance with statutory requirements, additional cost estimates were submitted to Congress in 1965, 1968, 1970, 1972, and 1975. Future estimates are to be submitted in January 1977.
In each of the reports to Congress, information was submitted regarding the difference in total costs reported. With the changes in the statutory requirements as to the total system concept and the enactment of new environmental and sociological requirements, it was expected there would be introduced elements of cost not considered in the initial estimates. These increased costs were not “overruns” or “errors” in previous estimates, but were rather, a reflection of changing construction prices and changes in law enacted by Congress in recognition of changing public need, including design changes for mobility, safety, and environmental requirements.
Table 2 categorizes the major influences affecting total costs and shows the cost increase in each category. Some elements of the 1973 highway legislation are yet to be implemented, and the permissive substitution of System segments and cost in urban areas will be reflected in the highway and mass transit construction programs in urban areas. These changes will affect the construction cost on the Interstate System.
Category No. |
Description of cost category | Estimate cost increase by years | |||||
1965 over 1961 |
1968 over 1965 |
1970 over 1968 |
1972 over 1970 |
1975 over 1972 |
Total | ||
1 | Unit price increase | $1,135 | $1,875 | $2,395 | $3,825 | $5,870 | $15,100 |
2 | Engineering cost increase | 161 | 385 | 350 | 125 | 515 | 1,536 |
3 | Right-of-way values—relocation assistance, homes and businesses
|
693 | 890 | 910 | 250 | 1,060 | 3,803 |
4 | Statutory design year change—added lanes, 4-lane minimum, etc.
|
739 | 675 | 320 | 100 | 515 | 2,349 |
5 | Statutory mileage increase, major System adjustments, etc.
|
941 | 930 | 4,155 | −235 | 30 | 5,821 |
6 | Added interchanges and grade separation structures
|
289 | 990 | 240 | 185 | 160 | 1,864 |
7 | Increase in roadway design, bridge width, tunnel clearances
|
445 | 1,245 | 3,265 | 1,015 | 2,355 | 8,325 |
8 | Additional safety elements on new and on completed sections
|
1,530 | 335 | 1,865 | |||
9 | Increased social, economic and environmental requirements
|
1,207 | 555 | 285 | 515 | 1,110 | 3,672 |
10 | Mass transit—fringe parking provisions of 1970 Act
|
125 | 125 | ||||
11 | Construction project overruns
|
257 | 257 | ||||
Subtotal[N 1] | 5,610 | 9,075 | 12,255 | 5,905 | 11,872 | 44,717 | |
Total Estimate 1961 = $41,000[N 1]
|
$46,800 | $56,500 | $69,870 | $76,300 | $89,200 |
484
- ↑ Id.