Introduction
The really big issue in urban transportation policy for at least a decade has been the controversy about how much emphasis to place on new investment in urban highways vis-à-vis improvements in public transportation facilities and services. This controversy is founded on disagreement over a number of underlying issues, including the effects of transportation on the pattern of urban development; the role of apparent consumer preferences in determining transportation investment; the use of the price system; and the role of the different levels of government. But before examining these issues and the policies they imply, it is well to ask: are the two modes of transportation (the private auto and public transportation) really as competitive as the heat of the controversy implies?
The Distinctive Roles of Transportation Modes
In American urban areas as a whole, travel in private automobiles accounts for roughly 95 percent of all travel. In the aggregate, travel by bus, subway, suburban railroad, taxicab, and ferry appears relatively unimportant, even in the very large metropolitan areas that have extensive transit, rail, and taxi services. This, however, refers to all kinds of urban travel, regardless of purpose of trip, location within the urban area, time of day or day of week. The urban transportation problem, however, can be more narrowly defined. Public policy is concerned with travel at the times and along the routes that involve congestion and needs for additional investment to improve service.
Much of the congestion problem is associated with journeys to work, because these tend to be concentrated into a few hours of each working day. Moreover, the worst of the journey-to-work congestion problem is connected with trips to and from the central business districts of large cities, because very large numbers of people are trying to move along a necessarily limited number........
