Effects of public policy

The benefits of mass transportation result from the utilization of these services: more utilization produces more benefits. Crowded buses and trains signify a smaller market share for the automobile, with its attendant air pollution, congestion, accidents, and excessive land consumption. Heavy utilization of mass transportation can produce a larger revenue stream from passenger fares, which can help support these systems, either by reducing subsidy requirements or, in a few very high-density travel corridors, actually covering all the costs of providing mass transportation.

There are a number of ways to increase and maintain mass transit ridership. These differ by context and government policy, and none offers guaranteed results. Keeping transit utilization high is much easier where competition from the automobile is limited. In Third World cities, where the automobile has never taken hold, transit, bicycles, and walking remain dominant modes. Cities are more densely settled, and work, shopping, and residential activities are closely intermingled so that trip distances are short. This encourages walking and the use of bicycles, with their low energy requirements. Even if mass transportation is slow and crowded, it may be the dominant mechanized travel option in such settings.

Cities in many developed countries in Europe and Asia have long-standing government policies that simultaneously controlled the growth of automobile ownership through high taxes on vehicles and their fuel; restricted land development to encourage high-density activity centres, including suburban new towns, as well as mixed land uses to keep trips short; and funneled a steady stream of public resources to subsidize mass transit operations and make capital investments to extend systems into new areas. These public investments in transit were generally not matched with similar investments in facilities for the automobile. Indeed, a number of cities around the world have restricted automobile travel to their downtown areas by defining auto-free zones (e.g., Gothenburg, Sweden), prohibiting the growth of parking, or charging high entry tolls for vehicles carrying only one or two people (Singapore).

In the United States the approach has been to allow the free market, for both travel and land development, to determine the role of competing modes. Mass transportation does attract high market shares where the automobile is inherently less competitive, as, for example, travel to dense downtown areas during the rush hours. In the central areas of larger cities such as New York, Boston, Washington, Chicago, and even Los Angeles, street congestion can be intense and parking fees high. Where high-quality mass transportation is available (particularly rail service, which is as fast as or faster than the automobile), with frequent departures and high reliability, it can capture 50 to 80 percent of all travel to downtown in the rush hour. At other hours of the day, the mass transportation share of downtown travel may drop to 20 percent, and across the regions in which such cities are centred, the all-day transit share may be as little as 5 to 10 percent of trips.

Mass transit is critically important to the economic and social health of these cities, and it is also important in other communities where its market share is lower but its contributions to peak-period congestion reduction and mobility assurance are significant. These effects provide the argument for public involvement in transit, through ownership, development, operation, and service subsidies. The key policy choices about mass transit in the United States concern how to spend public funds to produce these benefits, including decisions about capital investments for new and replacement technologies, the quantity and quality of services to offer, and how to pay for all of this.