This document is a summary of the 2004 Status of the Nation's Highways, Bridges, and Transit: Conditions and Performance report to Congress (C&P report). The C&P report is intended to provide Congress and other decision makers with an objective appraisal of highway, bridge, and transit physical conditions; operational performance; financing mechanisms; and future investment requirements. This edition of the C&P report is the sixth in the series that combines information on the Nation's highway and transit systems.
The main body of the report is organized into five major sections. Part I, "Description of Current System," includes the core retrospective analyses in the report, including chapters on the role of highways and transit, system and usage characteristics, physical conditions, operational performance, safety performance, and finance.
Part II, "Investment/Performance Analysis," includes the core prospective analyses of the report. As in previous editions, the future investment requirements analysis in this edition of the C&P report focuses on two 20-year scenarios for highways, bridges, and transit systems.
The highway investment requirements in this report are developed in part from the Highway Economic Requirements System (HERS), which uses benefit-cost analysis to optimize highway investment. The HERS model quantifies user, agency, and societal costs for various types and combinations of improvements, including travel time, vehicle operating, safety, capital, maintenance, and emissions costs.
Investment requirements for bridge rehabilitation and replacement are developed from the National Bridge Investment Analysis System (NBIAS). Comparable to HERS, NBIAS includes benefit-cost analysis in its calculations.
The transit investment analysis is based on the Transit Economic Requirements Model (TERM). The TERM consolidates older engineering-based evaluation tools and introduces a benefit-cost analysis to ensure that investment benefits exceed investment costs. Specifically, TERM identifies the investments needed to replace and rehabilitate existing assets, improve operating performance, and expand transit systems to address the growth in travel demand, and then evaluates these needs in order to select future investments.
Part III, "Special Topics," further explores some topics related to the primary analyses in the earlier sections of the report. Some of these chapters reflect recurring themes that have been discussed in previous editions of the C&P report, while others address new topics of particular interest that will be included in this edition only. Part IV, "Supplemental Analyses of System Components," builds on the analyses developed in Chapters 2 through 10 by focusing more closely on particular components of the Nation's highway and transit systems. Part V, "Afterword: A View to the Future," identifies potential areas for improvement in the data and analytical tools used to produce the analyses contained in this report, as well as describing ongoing research activities.