streets and highways, and parking area comprises another 10 percent. Ninety five percent of this area constitutes local streets and rural roads that carry 5 percent of the traffic, and 5 percent of the area is dedicated to highways and freeways that carry 95 percent of the traffic. These two types of roads are financed in very different ways. The local streets and roads that provide access to property are paid for from local property taxes and local sales taxes. The other five percent of roads is financed by user fees in the form of gas taxes or tolls. This has been very successful because it provides more money as traffic increases, and that money is used exclusively to build and maintain the roads. There is far less competition for resources than would be the case if government were to pay for roads out of general funds.

  1. The environmental impacts of the automobile. The automobile has had a mixed effect on health. Access to health care facilitated by the automobile is one of the most important variables for increasing life expectancy. But air pollution caused by exhaust emissions and water pollution caused by runoff from roads have had a negative effect, and disposal of old automobiles, tires, parts and motor oil cause additional environmental problems. But over the past few decades, enormous progress has been made, mostly through new technologies, and the United States is on its way toward creating a sustainable transportation system.

  2. Relationships between mobility or travel and urban form. The automobile has profoundly affected the form of cities. Earlier, city population densities were much higher, with resulting disease, fires, accidents, and other disasters. Public transit, the automobile, the creation of suburbs, and decentralization have lowered the densities and made the cities much more livable. Now this solution has given rise to new problems—sprawl, congestion, energy waste, pollution and even racial Segregation—and proposed solutions include a return to higher densities in the urban centers. However, it is now politically more difficult to redesign the cities, and only a few places, like Portland, Oregon, have been able to make significant gains in this direction.

  3. The impact of the transportation system on the distribution of well-being in society. Modern land use patterns are designed with the automobile as part of the system, and those who have no cars (the elderly, poor, minorities, and the disabled) are left out of some benefits. Automobiles also cause 41,000 deaths a year in the United States, including pedestrians and cyclists, more than all the wars in its history. It is the leading cause of death for those under 35 years of age. Important improvements have been made in vehicle design, seat belts, etc., but there has been less progress in traffic management. Some of the proposed innovations in this area involve applications of information technology to control traffic flow and charge for road use.

Wachs concluded by stating that in the United States, automobile use has had a generally beneficial effect on society. However, urban design and community planning has not been sufficiently sophisticated in coping with the automobile. Automobile users should be charged a greater proportion of the full social costs of their travel, and other modes of travel, like cycling, walking and transit need to be treated more fairly in transportation planning. While adequate roads and parking facilities should be provided, those who benefit from them should pay their full social costs, with due regard for the needs for sidewalks, bicycle paths, and transit facilities. It is possible to integrate urban transit and pedestrian facilities safely and economically with streets and highways and to protect urban parks, waterfronts, landmarks, and tourist attractions from being overrun by parked cars. Much of the criticism aimed at the automobile itself should be directed at the poor urban design decisions that have been the root of many of the inequities that characterize mobility in urban areas.



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement