TRANSPORTATION RESEARCH BOARD
Most long-distance trips begin in one metropolitan region and end in another less than 500 miles away. These “interregional” trips account for about three-quarters of all long-distance trips. Several recent developments have emphasized the importance of this segment of travel. Among them are California’s plan to invest more than $60 billion in a new high-speed rail line connecting the state’s southern and northern cities and the emergence of express curbside bus lines in the interregional corridors of the Northeast and in other parts of the country. In these and other cases where new transportation systems—some requiring large public investments in long-lived infrastructure—are being considered, interregional travel demand, transportation service options, and corridor traffic and trip-making patterns need to be well understood.
This study reviews the demand for interregional travel in the United States and the uncertainties that arise in supplying transportation services and infrastructure to accommodate it. Consideration is given to relevant experience in other countries, especially in providing intercity passenger rail. A central finding is that appropriate analytical tools and up-to-date data on long-distance travel in the United States are lacking, which complicates decisions about how to invest in the country’s interregional corridors in ways that will serve future travelers most effectively and further other policy goals such as protecting the environment, enhancing safety, and curbing energy use. In addition, the study finds significant gaps in the decision-making capacity itself, largely because transportation funding sources and institutions do not align well with the country’s interregional corridors, which can span multiple states.
Experience at the metropolitan level suggests that filling this institutional gap will provoke demand for better travel data and the analytical tools needed to inform public investments in transportation systems serving interregional markets. After the key study findings are summarized, several recommendations are offered with the intent of improving long-distance travel data, supporting the development and application of state-of-the-art analytical tools, and providing incentives for the creation of interregional planning entities to inform regional and corridor-level transportation decisions.
Because of outdated travel behavior survey data, long-distance travel is not nearly as well understood as local travel.
Understanding of long-distance travel in the United States is informed mainly by the American Travel Survey (ATS), a national survey of long-distance trips conducted in 1995. If a long-distance travel survey were conducted today, it would likely reveal many travel patterns not observed by the ATS, as would be expected after two decades of demographic, economic, and technological change. Interregional travelers who do not travel by automobile must typically make at least one mode transfer near the origin and destination, and they may use different modes for the access and line-haul portions of the trip. Such trip complexity can create challenges for data collection and modeling. This complexity, coupled with a reliance on travel information and behaviors observed a generation ago, is a source of considerable uncertainty for today’s decision makers as they plan and invest in interregional transportation systems that will be used for decades to come.
The automobile is used for most interregional trips, especially by families and other people traveling together for nonbusiness purposes. Understanding the strong appeal of driving for nonbusiness travel is critical in planning transportation investments to accommodate interregional travelers.
The private automobile has many service attributes that differentiate it from other modes. Among them are its ability to provide door-to-door service and carry multiple people at little extra cost. These attributes and widespread automobile ownership make the automobile the mode of choice for most interregional trips, especially by families. However, driving is not an option for people who lack access to a car. In addition, it can have limited utility for those who are traveling alone, for business purposes, for longer distances, or to locations such as downtowns where a car is not needed and is costly to park. The car’s dominance in interregional travel means that transportation planners have a critical need for information concerning whether and how uses of the automobile may be changing over time and in specific markets—for example, because of changes in vehicle availability, technology, operating costs, and utility.
The recent proliferation of intercity express bus services illustrates the uncertainties associated with forecasting the demand for interregional travel and with anticipating how the demand will be met.
During the 1990s, the nation’s intercity bus industry was in the midst of a long-term decline in ridership. Today, the industry has been rejuvenated by bus companies providing nonstop service between the downtowns of major cities. The express bus appears to have filled a void in the low-fare and shorter-haul interregional market. It accommodates mostly solo travelers who lack access to automobiles, find driving too expensive or a car unnecessary at the destination, or want to make enjoyable or productive use of travel time through onboard amenities and the uninterrupted use of portable electronic devices. On the one hand, public officials noticing this renaissance might question whether capital-intensive transportation investments are needed or will be competitive with the low-cost private bus. On the other hand, they might view this development as indicative of more people seeking transportation alternatives to the automobile and thus perhaps as a signal for investing in other options, such as intercity train service and priority access lanes and terminals for intercity buses.
Sparse interregional train service throughout much of the country can be attributed to a number of factors. One is the preponderance of trains operating over the lines of private freight railroads, which limits opportunities for competitive schedule times and frequencies.
Intercity trains in most of the country’s interregional corridors operate on freight lines. Corridor investments to increase passenger train speeds and frequencies are generally not attractive to the private freight railroads that own these lines, and they may be undesirable if they hinder the efficient movement of freight. With their skeletal passenger train service and their limited prospects for introducing competitive service levels on heavily trafficked freight lines, few corridors other than the passenger-oriented Northeast Corridor (NEC) have developed a large ridership base. The absence of such a base increases the uncertainty associated with introducing competitive passenger service, particularly when a large commitment of public funds is needed for infrastructure development.
The NEC is the only interregional corridor having train frequencies and schedule times that can compete successfully for market share with airlines, buses, and automobiles, and it accounts for most interregional train ridership in the United States. The 400-mile corridor, which links Boston, New York, and Washington, contains many large metropolitan areas that are closely spaced and positioned linearly so that multiple city-pair markets can be served with frequent trains on a single line. Another factor fundamental to the success of train service in the NEC is Amtrak’s control of the electrified right-of-way, which carries little freight and is used mainly by local commuter and intercity passenger trains.
About the Transportation Research Board
The mission of the Transportation Research Board is to provide leadership in transportation innovation and progress through research and information exchange, conducted within a setting that is objective, interdisciplinary, and multimodal.