In 1998, with the Interstate System essentially complete, FHWA's Office of Engineering compiled information about development of the program. In making this information available to the public, we have not updated the material. All information is as of 1998 when the Office of Engineering compiled the report.

Engineering Data

Report Index

Introduction

Part I - History

• A Brief History of the Interstate System
• Legislative History Related to Size of the System
• Interstate Designations
  • 2,102 miles after 1956 Act
  • 1,472 miles after 1968 Act (from 1,500 authorization)
  • 402 mile added under Howard-Cramer Additions
  • Individual Additions via Special Legislation
  • Additions under 23 U.S.C. 139(a)
  • Additions under Section 332 of 1995 NHS Act

Part II -- Mileage

• Summary
• List of Individual Routes and Lengths by State
• Miles of Interstate Routes By State
• Main Routes (1- and 2-Digit Route Numbers)
• Auxiliary Routes (All 3-Digit Routes)
  • Interstate Loop Routes
  • Interstate Spur Routes
• Mileage by Urbanized Area

Part III -- Cost

• The Interstate Cost Estimate (ICE)
  • Summary of the ICE Process
  • Listing of ICE Reports to Congress
  • Reasons for Cost Increases in ICEs
• Cost as Reported in the 1991 ICE
  • System Cost by PE, R/W & Construction
  • Cost of PE, R/W, Construction & Other
  • Cost by State - Alphabetical
  • Cost by State - Ranked by Cost
  • Cost by State - Detailed
  • Cost by Route - Detailed
• Cost Updated to 4/30/98

Part IV -- Funding

• Authorizations of Interstate Construction (IC) Funds
  • Annual Authorizations & Legislative Reference
  • Legislative History of Annual Authorizations
• Basis for Apportioning IC Funds
  • Background, etc.
  • Table With References to Applicable ICE and Legislation
  • Apportionment Factors from ICE Reports to Congress
  • IC Apportionment Deferrals
• Minimum Apportionments of IC Funds
  • Legislative History
  • Table of Minimum Apportionments
• Interstate Discretionary (ID) Funds
  • Allocations by State & Year
  • "Double Dipping"
• Transfers of Interstate Funds [23 U.S.C. 119(d)]

Part V -- Interstate Withdrawal-Substitution Program

• Legislative History
• Howard-Cramer Interstate Substitutions, 103(e)(2)
  • Maps of Withdrawn-Substituted Interstate Routes
• List of Withdrawal Actions, 103(e)(4)
  • Individual Withdrawals -- Background and Map

Part VI -- Interstate Status and Progress

• FHWA Bulletin of Status as of 12/31/97
• States With All Mileage Open to Traffic
• Year-by-Year Progress

Part VII -- Miscellaneous Interstate Facts

• Numbering Interstate Routes and Exits
• Fun Facts (Trivia)
• Vehicle Miles Travelled
  • Rural/Urban by Year
  • States with Heaviest Travelled Routes
• Tunnels Built with Interstate Construction Funds
• Capital Beltway - Washington, DC
• Central Artery/Third Harbor Tunnel - Moston, MA

Part VIII -- Other Interstate Programs

• Interstate 3R/4R
• Interstate 4R Discretionary
• Interstate Maintenance
• Interstate Reimbursement

Introduction

What This Notebook Attempts to Do

Part I - History
Many authors have written detailed histories of the Federal-Aid Highway Program and in particular the Interstate System. The high points in the development of the Interstate System are summarized in Part I of this notebook. Part I also includes a bibliography of historical books and articles on the origins of the Interstate System.

Part II - Mileage
Interstate routes have been designated or added to the system under several provisions of law. Part II includes various types of listings of all the Interstate routes, and their lengths and indicates the mileage designated under each provision.

Part III - Cost
The Interstate Cost Estimate (ICE) process is described and the costs of the System with breakdowns by State and route are provided from the 1991 ICE and updated to 1998.

Part IV - Funding
Details on annual authorizations, ICE reports to Congress, apportionments, allocations, transfers, etc.

Part V - Withdrawal-Substitution
Many segments became controversial for a number of reasons and were never built as originally planned. Part V identifies these routes and describes the two parts of the Interstate Withdrawal-Substitution Program, Howard-Cramer substitutions under 23 U.S.C. 103(e)(2) and withdrawals under 103(e)(4). Maps are included showing all withdrawals.

Part VI - Status/Progress
Includes summaries of year-by-year and State-by-State progress on constructing the system and its current status.

Part VII - Miscellaneous Facts
Provides a number of facts such as numbering of routes and exits, traffic, tunnels, and includes trivia questions frequently posed to FHWA about the first, the longest, the most, the least, etc.

Part VIII - Other Programs
Describes some of the other Interstate programs including 3R, 4R, 4R Discretionary, Maintenance, and Reimbursement.

Credits

Much of the credit for developing the Interstate System is given to President Eisenhower, members of Congress, and FHWA and State Leaders.

This notebook is dedicated to the four engineers who led the BPR - FHWA Washington Office branch which for nearly 40 years daily dealt with the Interstate System, its cost and funding, eligibility issues, legislation, completion status, etc. The branch was variously known as the Interstate Reports Branch, the Interstate Management Branch, and the Interstate & Program Support Branch. We are indebted to these four engineers:

Henry R. Paterick
Curtis L. Shufflebarger
Lawrence A. Staron
Donald J. Marttila