1.0 Introduction

1.1 The Problem of Congestion

The last several decades have witnessed steady growth in the demand for freight transportation in the United States, driven by economic expansion and global trade. But today, the nation is entering the early stages of a capacity crisis. Freight transportation capacity is expanding too slowly to keep up with demand, and the freight productivity improvements gained though investment in the Interstate highway system and economic deregulation of the freight transportation industry in the 1980s are showing diminishing returns.

The effects of growing demand and limited capacity are felt as congestion, upward pressure on freight transportation prices, and less reliable trip times as freight carriers struggle to meet delivery windows. Higher transportation prices and lower reliability can mean increased supply costs for manufacturers, higher import prices, and a need for businesses to hold more expensive inventory to prevent stock outs. The effect on individual shipments and transactions is usually modest, but over time the costs can add up to a higher cost of doing business for firms, a higher cost of living for consumers, and a less productive and competitive economy.

Freight congestion problems are most apparent at bottlenecks on highways: specific physical locations on highways that routinely experience recurring congestion and traffic backups because traffic volumes exceed highway capacity. Bottlenecks on highways that serve high volumes of trucks are "freight bottlenecks." They are found on highways serving major international gateways like the Ports of Los Angeles and Long Beach, at major domestic freight hubs like Chicago, and in major urban areas where transcontinental freight lanes intersect congested urban freight routes.

Freight bottlenecks are a problem today because they delay large numbers of truck freight shipments. They will become increasingly problematic in the future as the U.S. economy grows and generates more demand for truck freight shipments. If the U.S. economy grows at a conservative annual rate of 2.5 to 3 percent over the next 20 years, domestic freight tonnage will almost double and the volume of freight moving through the largest international gateways may triple or quadruple. Without new strategies to increase capacity, congestion at freight bottlenecks on highways may impose an unacceptably high cost on the nation's economy and productivity.

1.2 The Federal Role

The Intermodal Surface Transportation Efficiency Act (ISTEA) and the Transportation Equity Act for the 21st Century (TEA 21) called upon the Federal government to develop a "National Intermodal Transportation System that is economically efficient and environmentally sound, provides the foundation for the Nation to compete in the global economy, and will move people and goods in an energy efficient manner…." ¹ The recently enacted Safe, Accountable, Flexible, Efficient Transportation Equity Act: Legacy for Users (SAFETEA LU) reaffirms the need for Federal government leadership in freight transportation. Therefore, the U.S. Department of Transportation (DOT) will have an increasing responsibility to develop and shape freight transportation policy options and programs. To do so, the Federal Highway Administration (FHWA), which oversees a National Highway System that carries 71 percent of all freight tonnage, must build a new generation of freight planning and policy analysis tools. The FHWA must be able to understand freight patterns, anticipate changes, and estimate the benefits and costs of capital investment, policy, and regulatory strategies to improve freight transportation.

The FHWA Office of Policy has begun to build these capabilities under is its "Strategic Analysis of Multimodal Transportation Policy Options" initiative. This initiative will develop a multimodal freight transportation network model and benefit/cost analysis tools that can evaluate capital, policy, and regulatory strategies for freight transportation.

1.3 The Objective of This Paper

This white paper is an initial effort to identify and quantify, on an national basis, highway bottlenecks that delay trucks and increase costs to businesses and consumers. The paper is the first to look specifically at the impacts and costs of highway bottlenecks on truck freight shipments. The paper builds on three streams of research:

• Bottlenecks – The paper improves and applies a bottleneck identification methodology developed for a project commissioned by American Highway Users Alliance that identified general highway bottlenecks—"Unclogging America's Arteries: Effective Relief for Highway Bottlenecks: 1999-2004."² That project built on prior work by Cambridge Systematics and others for the FHWA's mobility monitoring initiative and the FHWA's Highway Performance Monitoring System. The improved method provided a means of rapidly and systematically identifying and quantifying the congestion and delay associated with freight bottlenecks.
• Freight Flows – The bottleneck identification methodology was applied to commodity and truck flow estimates developed by Battelle, Cambridge Systematics, and others under the FHWA's Freight Analysis Framework project.³ The project integrated data from a variety of public and private sources to estimate commodity flows and related freight transportation activity among counties, states, regions, and major international gateways for the years 1998, 2010, and 2020. It provided the first, comprehensive picture of truck freight flows over the National Highway System, and provided a foundation for identifying truck freight bottlenecks and quantifying delay to trucks at the bottlenecks.
• Congestion – The paper also drew on research and findings reported by the Texas Transportation Institute's series of studies and reports on urban mobility, and on research on congestion undertaken by Cambridge Systematics and the Texas Transportation Institute for the FHWA's Office of Operations.⁴,⁵ The paper begins to fill in information about impacts and costs of congestion on trucks and freight transportation separate from the impacts and costs of congestion on automobiles and passenger transportation, which have been the general focus of prior research.

The paper sets up a typology for highway freight bottlenecks, identifies an initial list of significant bottlenecks, and recommends ways to improve the analysis of bottlenecks and use the information in developing policies, programs, and projects to improve freight flows. The methods, findings, conclusions, and recommendations of the white paper are organized and presented as follows:

• Section 2.0, National Freight System Capacity and Performance, describes recent trends in national freight system capacity and performance and the implications of increasing freight demand and diminishing freight transportation capacity for shippers and carriers.
• Section 3.0, Highway Truck Bottleneck Typology, sets out a typology of highway bottlenecks for describing and classifying bottlenecks. The typology is based on the type of bottleneck constraint, the type of roadway, and the type of freight route. The typology is necessary to avoid double counting when calculating truck hours of delay and to establish—for future policy and program analysis work—a framework for attaching strategies and costs for congestion mitigation to each type of bottleneck.
• Section 4.0, Methodology, describes the data and analytical methods used to identify highway bottlenecks and estimate the truck hours of delay accruing to trucks caught in the bottlenecks.
• Section 5.0, Highway Truck Bottlenecks, summarizes the key findings about the number of bottlenecks identified and the truck hours of delay associated with each type of bottleneck.
• Section 6.0 presents the Conclusions and Recommendations of the paper.

The paper has four appendices.

• Appendix A lists bottlenecks caused by urban interchanges (freeway-to-freeway, and freeway-to-arterial roadway);
• Appendix B lists bottlenecks caused by steep grades on intercity and urban roads;
• Appendix C lists bottlenecks caused by congestion at signalized intersections on arterial roadways; and
• Appendix D lists bottlenecks caused by congestion at highway lane-drops (e.g., where highways narrow from three to two or two to one lane) on freeways and arterial roadways.