Accommodating interregional travel: Insights and opportunities

By Mary Ebeling

The Transportation Research Board Special Report 320, Interregional Travel: A New Perspective for Policy Making, offers important insights into interregional travel. This category, defined as trips between 100 and 500 miles, makes up approximately three-quarters of long distance trips but suffers from insufficient data for making system investments.

In addition to a lack of data, there are few organizations or agencies that plan and track interregional travel.

The report notes that, “In the United States, few institutional structures align with transportation systems that are regional in scope rather than local or national.” In the absence of such structures, to help coordinate interregional transportation planning, funding, construction, and operations, states and regions can look to the NEC and models of inter-governmental coordination like multi-state Metropolitan Planning Organizations.

The last American Travel Survey, which comprehensively documents long-distance travel and provides an important basis for decision making, was completed in 1995 and therefore outdated. While there is information from the 2001 National Household Travel Surveys and FHWA trip tables from 2008, it is not adequate to provide needed data related to changes in interregional travel preferences. This situation creates uncertainty for departments of transportation as they plan for the future. To rectify this problem, the report recommends:

  1. Supporting the establishment of a national data program focused on observing and understanding the behavior of long-distance travelers and the transportation services available to them.
  1. Supporting the development and application of state-of-the-art analytical tools for planning and prioritizing interregional transportation investments, including methods for representing the uncertainties that can accompany decisions to invest in long-lived transportation systems that require forecasting of public benefits and traveler demand.
  1. Creating, by seeking authority from Congress as necessary, the incentives for states to collaborate in developing multimodal, interregional transportation planning and decision-making organizations.

The study finds that interregional travel is multimodal, but the preferred mode varies by region. Outside of the Northeast corridor, which has the nation’s most robust train service, trips of less than 300 miles are most commonly made by car, with families and groups of non-business travelers preferring driving. This is particularly true in the Midwest and western states, where regional cities are more widely separated than in the more densely populated East Coast. Longer trips tend to be made by air. Notably, between 1995 and 2008, rail travel more than doubled and intercity express buses experienced a resurgence, suggesting a need for additional study before making major infrastructure investments.

Although driving is the preferred mode for many trips, the study also found that there is a significant percentage of trips where a car is inappropriate or undesirable, supporting the finding that rail and intercity express bus service have become more popular. These trips include solo business trips, where driving precludes work, and trips where traffic conditions or lack of parking at the destination mean a car is a burden.

Mary Ebeling is a Transportation Policy Analyst at SSTI.