The National Academies

NCHRP 20-24(052) [Final]

Future Options for the National System of Interstate and Defense Highways
[ NCHRP 20-24 (Administration of Highway and Transportation Agencies) ]

  Project Data
Funds: $726,793
Research Agency: PB Consult, Inc.
Principal Investigator: David Gehr
Effective Date: 5/11/2006
Completion Date: 12/5/2007

The Dwight D. Eisenhower System of Interstate and Defense Highways was planned more than 75 years ago, and the system has many sections that are more than 50 years old. The mechanism for funding the system was enacted 49 years ago. Early policy papers in the 1930s and 1940s assessed options on such issues as system size and extent, purpose, interstate travel versus intercity travel, and funding mechanisms (e.g., tolls, pay-as-you-go gas taxes, and use of federal eminent domain with excess right-of-way acquisition to gain value capture versus state-by-state processes).
Since the Interstate System was laid out, the population and vehicle travel demands in the nation have increased far beyond any forecasts, and the demographics in terms of ethnicity, age, population, and geographic distribution have changed significantly as well. Freight movement has exploded, and international trade is far different from 75 years ago and will be significantly different 50 years from now.
The recently enacted SAFETEA-LU includes a provision (Section 1909(b)) that establishes a National Surface Transportation Policy and Revenue Study Commission (the Commission) to explore a range of legislative and policy approaches for the Interstate for the next 15, 30, and 50 years. The commission will prepare a report to Congress; the report is scheduled to be delivered late in 2007.
Recognizing the changes facing the nation’s highway transportation system and to participate effectively in discussions associated with the work of the Commission and other national policy initiatives, the American Association of State Highway and Transportation Officials (AASHTO) and its member its member departments of transportation (DOTs) have been working to develop a strong, clear vision for the nation's future highway needs and options. This project was intended to provide analysis supporting identification of options for the future of the U.S. Interstate Highway System, with the greatest potential for improving highway operations and capacity, including intermodal passenger and freight connectors and access to military bases, strategic ocean ports, and airfields.
The project entailed analysis in several areas:
  • The criteria and process for designating and funding the existing Interstate Highway System and National Highway System designations, and how the Interstate System designation might be broadened to include selected NHS segments
  • Existing research on the economic impact of the Interstate Highway System, including the effects on U.S. economic productivity, the rate of return on investment in the system, and user benefits (including reductions in fatalities and serious injuries), that would provide a framework for assessing the economic benefits that would accrue to expanding the current system network and adding facilities to the system
  • Policy issues and scenarios that should be considered in suggesting a vision for the Interstate system’s future, for example, ensuring that all cities of a certain size are linked and that all major military installations, water ports (including those designated as strategic by the U.S. Department of Defense), airports, and rail heads--as well as all state capitals--are linked with full access-controlled facilities
  • Estimates of future travel demand for system, for 15-, 30-, and 50-year time periods, considering possible changes in the proportions of large trucks and automobiles using the system and evolution of truck sizes and weights
  • Estimates of restoration, rehabilitation, reconstruction, and resurfacing needs of the current Interstate Highway System in 15-, 30-, 50-year time periods, giving consideration to safety and security needs as well as mobility needs and how innovative materials, design and construction techniques, and contracting practices may facilitate restoration, rehabilitation, reconstruction, and resurfacing and reduce total lifecycle costs to government, users, and society
  • Estimates of needs for lane additions to the system in both rural and urban areas, considering particularly the needs for exclusive truck lanes, general capacity requirements, and HOV/HOT lanes, developed as toll or non-toll facilities
  • Estimates of investment requirements for new corridors to be added to the current system and new intermodal connections to key public, commercial, and defense rail, transit, air, and water terminals and ports and critical military installations, including both upgrading existing roadways and building new facilities, and giving particular consideration to special safety features, motorist information (511) systems, regulatory ITS activities (e.g., border crossings, hazmat tracking and routing, size and weight administration); and other innovative technologies that might be adopted, and alternative strategies for meeting future investment requirements
In addition to these analyses, the project included an investigation to develop the scope for a special study of the extent to which the US DOT Condition and Performance Reports and AASHTO Bottom Line Reports may be underestimating national highway system reconstruction needs and costs, considering methods and models used, data and assumptions, and the scope and context for the analyses. The research team worked with a selected group of knowledgeable individuals and the NCHRP project panel, conducting interviews and group discussions to identify the possible extent of the hypothesized bias, availability of data to assess and document that bias, and key issues related to the sources of underestimation. The researchers proposed methodologies for assessing the magnitude of rehabilitation and reconstruction need and cost underestimating and a plan for applying these methodologies in a subsequent research study
The project also entailed involvement of the consultant team in discussions with several AASHTO advisory groups and support to an AASHTO-sponsored policy conference on the future of the Interstate, held in June 28-29, 2006, in Washington, DC, and attended by approximately 100 participants.
PRODUCT AVAILABILITY: The work of the project was reported in a series of technical memoranda that were provided to AASHTO. One of these memoranda presents the principal results of the analyses and options for the future Interstate system. This agency report, Future Options For The National System Of Interstate And Defense Highways: Task 10 Final Report, may be viewed and downloaded by clicking here.

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