The mass use of motor vehicles was bound to have some unforeseen and undesirable consequences, of which three can be singled out: traffic congestion, air pollution, and highway accidents. The approach to each of these problems illustrates a common tendency to blame the technology, rather than the way in which the technology has been used.
City streets were congested long before the automobile existed, but the problem has been compounded enormously by the masses of motor vehicles that enter or leave cities at peak traffic hours. The constantly growing number of automobiles throughout the world adds to the difficulty of finding remedies for congestion. The heart of the problem is that few city street systems were originally designed for automobile traffic. Reliable estimates are that some two-thirds of the vehicles in central business districts are passing through and should have been routed on different highways around the city. Remedying this situation is difficult and expensive. It calls for modern highways to provide both ready access into downtown areas and ways to avoid them. Programs for this purpose encounter vigorous opposition, frequently justified, on the ground that building freeways in cities disrupts neighborhoods and destroys scenic or historic areas.
The widespread use of automobiles for business travel has also led in many cities to a decline in public-transit systems, and the need to develop and use mass transit has been much discussed. Given the trend toward dispersal of people and businesses from urban areas, it seems doubtful that mass transit will appreciably diminish motor vehicle traffic. Still, in most cities, bus systems can provide the needed capacity for public transportation and are the most economical way of doing so. The building of "light-rail" and subways have helped dial with this problem.
Atmospheric pollution predates the automobile, but the concentration of many thousands of motor vehicles in large cities has given the problem a new dimension. Automobile exhausts commonly contribute half the atmospheric pollutants in large cities and even more in cities where atmospheric and topographic conditions cause the smog formation. In the 1960s, federal and state legislation in the United States required the installation of catalytic converters and other controls on motor vehicles to restrict the emission of pollutants.
Exhaust fumes from the engines of automobiles contain a number of polluting substances, including carbon monoxide and a variety of complex hydrocarbons, nitrogen oxides, and other compounds. When acted upon by sunlight, these substances undergo a change in composition producing the brown, smog for which Los Angeles is well known. Efforts to reduce pollution from automobile engines and to develop pollution-free engines may eventually eliminate the more serious air pollution problems. In the meantime, however, air pollution has driven many forms of agriculture from the Los Angeles basin, has had a serious effect upon the pine forests in nearby mountains, and has caused respiratory distress, particularly in children, elderly people, and those suffering from respiratory diseases.
Los Angeles is neither a unique nor the worst example of polluted air. Tokyo has such a serious air-pollution problem that oxygen is supplied to policemen who direct traffic at busy intersections. Milan, Ankara, Mexico City, and Buenos Aires face similar problems. Although New York City produces greater quantities of pollutants than Los Angeles, it has been spared from an air-pollution disaster only because of favorable climatic circumstances. The task of cleaning up air pollution, though difficult, is not believed to be impossible. Use of fuels that are low in pollutants, such as low-sulfur forms of petroleum; more complete burning of fossil fuels, at best down to carbon dioxide and water; and the shift to less polluting forms of power generation, such as solar or electrical cars in place of combustion engines--all are methods that can be used for controlling pollution.
Highway accidents create a distressing toll of fatalities and injuries wherever there is widespread use of automobiles. Each year there are hundreds of thousands of motor vehicle fatalities worldwide and about 50,000 in the United States alone. The social and economic costs of such accidents are enormous. Efforts to improve highway safety have been successful in most countries, but a reduction in the ratio of fatalities and injuries per distance traveled is often offset by increases in numbers of accidents because of the ever-growing use of motor vehicles.
Beginning with the National Traffic and Motor Vehicle Act of 1966, the United States has required automobiles to have safety features such as seatbelts. By the early 1990s, all new cars sold in the United States were equipped either with automatic seat belts or with air bags that inflate upon impact. In 1973-74 the US Congress, attempting to reduce fatalities and conserve fuel, passed a law making 55 miles per hour (mph) the national maximum speed limit. According to the Department of Transportation, the law resulted in a slower, more uniform flow of traffic that saved 18,000 lives between 1974 and 1979. Many state officials, however, especially those in Western states, raised strong opposition to the national speed limit, arguing that it imposed economic and personal hardship on people who had to travel long distances in short periods of time. In the late 1980s, states were allowed to raise the maximum speed limit on certain highways to 65 mph, and now even 75 mph on some highways.