Conventional wisdom holds that telecommunications is a natural substitute for transportation. Digital traffic on the fiber optic and wireless networks of the National Information Infrastructure (NII) can replace vehicle traffic on the streets and highways of the national transportation infrastructure. For example, telephone calls and videoconferencing can replace travel to meetings, and electronic-mail transmission of documents substitutes for postal delivery.

A leading example of travel substitution is telecommuting, which means using telecommunications to replace commuting between home and work. Telecommuting accounts for 7.6 million U.S. workers as of early 1993, up 15% from 6.6 million in 1992. The U.S. Department of Transportation (USDOT) estimates that telecommuting by the year 2002 will reduce the annual total vehicle miles traveled (VMT) by just 1% below the level expected to be seen if there were no telecommuting. A follow-up study by the U.S. Department of Energy (USDOE) calculates that the reduction in mileage from telecommuting by 2002 is likely to be even less because of (1) commuters living further from work, and (2) other travelers taking the road space vacated by telecommuters. However, telecommuting is not the only way that telecommunications can act as a substitute for transportation. Other examples of telecommunications substituting for travel include:


Telecommuting is only a small part of a large and expanding set of processes that govern how the National Information Infrastructure makes an impact on transportation. Present and future NII applications in health care, public education, government, and manufacturing offer opportunities for general societal benefits that are more significant than travel savings.


Because of the popularity and effectiveness of telecommuting as a work practice, telecommunications is becoming embedded primarily as a transportation substitute in the thought processes of transportation researchers and government planners. But a closer examination of the U.S. experience over the last few decades does not reveal a natural evolution of telecommunications substituting for travel. Both grow together, one feeding the other. Travel per household is rising, urban congestion is increasing, and latent demand for travel emerges clearly when new road capacity is opened up, even as the NII is expanding. This report provides additional, cautionary perspectives on the idea that telecommunications is a force for reducing the need to travel. As telecommunications volumes build independently of direct substitution for transportation, an opposite effect occurs, namely, travel stimulation. A number of distinct stimulation effects can be identified:


The deployment of interactive, more functional, higher bandwidth communications into homes and rural areas will allow more telecommuting and other travel substitution practices. But at the same time a better telecommunications infrastructure will probably reinforce the dynamics that make telecommunications a travel stimulator as well. More powerful telecommunications will feed all of the ways listed above in which telecommunications expands the motivations to travel.

Other benefits of the NII are more important to the nation than travel savings: support of health care reform, efficient government, better education for our children, and rising manufacturing competitiveness. Telecommuting, in particular, is a very useful practice for stronger reasons than travel savings. It provides a work environment where workers can be more productive and closer to their families at the same time.

Whether the widespread deployment of more powerful, higher bandwidth telecommunications will lead advanced economies to show growing telecommunications usage per unit of economic output relative to transportation intensity depends significantly on changes in the price-performance of transportation. In the United States, for example, the cost of driving automobiles, based on fuel prices, vehicle prices, and taxation, is declining. This cost trend tends to work against trip substitution even while continual improvements in the price-performance of the NII supports substitution. An analytical, econometric determination of how telecommunications and transportation have been substituting for each other or complementing each other as economic inputs during the past few decades of NII expansion is an important follow-up research need coming out of this study.


A dominant public policy paradigm today is that telecommunications yields telecommuting which yields travel savings. The wide impact of telecommunications on the economy and society in contrast to the limited travel impact of telecommuting suggests that a better paradigm is now needed: Telecommunications yields some travel savings through telecommuting and other travel substitution effects, but also sets up a countervailing mechanism of travel stimulation that needs to be more widely recognized and better understood.

Governments must learn to coordinate public policy on telecommunications, transportation, land use, and capital facilities investment in light of the interactions described here. The overall challenge is to allocate resources and attention reasonably across the entire spectrum of public facility systems that provide support for the transactions and relationships comprising economic and social life. Such systems include the cables, circuits, services, and computers of the National Information Infrastructure; the roads and airports of the transportation system; and physical locations like schools, libraries, clinics, and meeting halls where people interact directly with other people.


A more explicit and complete inclusion of telecommunications in planning processes for improving the overall transportation system is a government responsibility deserving higher visibility at the state and metropolitan-area level and the encouragement of USDOE. Telecommuting and other telecommunications applications cut across both the supply and the demand sides of transportation, and are part of both the problem and the solution of state and metropolitan regions meeting the air quality and mobility goals mandated by the Federal Clean Air Act Amendments and the Intermodal Surface Transportation Efficiency Act.

Consideration of telecommunications would fit well into a least cost, integrated resource planning (IRP) framework that incorporates travel substitution, stimulation, and system management. IRP transfers ideas and methods that are now successfully used in electric energy planning to the transportation arena.

Also, government policy could focus on promoting and ensuring telecommunications-based alternatives to travel for the inevitable future periods when travel becomes difficult or expensive due to disruptions from special events, weather, disasters, or oil supply interruptions.

Although government policy intervention to accelerate the deployment of higher bandwidth and other more powerful telecommunications capabilities cannot be justified by the potential for travel savings alone, there are many other government roles in developing NII technology and applications that make productive use of tax dollars:

In short, government leaders must take their vision for transportation changes in the information age beyond telecommuting to a much larger set of NII applications that comprehensively affect the movement and location patterns for both organizations and individuals. Basing public policy on a more complete understanding of the new information technologies and their patterns of use will reduce the costs and increase the benefits to our society and economy from the parallel infrastructures of transportation and information.

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