Light-Rail Systems as a Response to Traffic Congestion

Description of Technique
This technique consists of building an on-the-surface fixed-rail public transit system in order to expand the transportation capacity of a metropolitan area. “Light rail” differs from “heavy rail” because the former (1) often uses tracks or rights-of-way of existing railroads for movement; (2) relies primarily on surface tracks rather than subway tracks, and often on surface tracks running on existing city streets rather than totally separate rights-of-way, thus permitting entry on a level with the street; (3) involves smaller trains (fewer cars per train and smaller cars) with less frequent headways; and (4) usually involves a limited number of routes servicing only relatively limited portions of the entire region, rather than a comprehensive set of routes designed to serve all parts of the region. The Light Rail Transit Association classifies systems as either “tramways” or “light rail systems,” with the former resembling the streetcars of yore. However, these two types closely resemble each other and form a continuous spectrum of variations rather than two clearly separate categories.

Potential Benefits of Technique From General Public Point of View
The major purposes of light rail systems are (1) to remove many travelers from highways, thereby reducing traffic congestion and air pollution; (2) to provide mobility for persons who cannot travel by private vehicle, either because of age, disability or poverty; (3) to strengthen the economic vitality of a region’s central business district, which is normally a key destination point in every light rail system; (4) to provide alternatives to private vehicle transportation without incurring the high costs of a complete heavy rail or metro system; and (5) to save the costs of building more highways. However, the extent to which it achieves these goals is a matter of hot dispute across the nation.

Potential Drawbacks of Technique from General Public Point of View
The potential drawbacks of this technique are:

• When a city builds a light rail system, it often changes its previous bus routes to channel public transit users to the new system. This may result in a decline in the quality and quantity of bus service, and even a net decrease in total public transit ridership, including both bus and light-rail users, even if light-rail usage equals or exceeds initial forecasts. The • Light rail systems require substantial public subsidies for both construction costs and operating costs. Yet they may carry far fewer persons per million dollars of public subsidy than would additional highway capacity.

• Service on light rail systems is rather slow because they have many stops—more than heavy rail systems. Critics claim the Portland light rail system moves at only an average of 19 miles per hour.

• The argument that light rail reduces traffic congestion during peak hours is probably false, for two reasons:

• Many people who ride light rail systems formerly used buses. Therefore, their shift does not significantly reduce peak-hour traffic. However, in some cases where buses connect to light transit outside a central business district (CBD) and passengers switch to the light rail system, the number of buses entering the CBD may decline. This happens in Denver, for example.

• If a significant number of travelers shift from private vehicles to light rail during peak hours, they will be replaced on highways by other private vehicle users moving from other routes, other times and other modes. This is the Principle of Triple Convergence.³⁰

Strategic Considerations for NAIOP Members Faced with Technique
The light rail systems that appear to be most successful link major outlying population centers or employment centers (such as regional airports) with the central business district. Thus, the St. Louis system connects the airport with downtown, major museum centers, a major medical center, and a large park.

A study by Judy Davis and Samuel Seskin shows that light rail cost efficiency varies directly with the total employment in the CBD and residential density within 10 miles of the CBD.³¹ It also varies somewhat less forcefully with the density of the CBD (employment per gross CBD acre), although ridership on heavy rail commuter systems is even more affected by CBD density. Light rail systems are less effective at serving areas that are more than 10 miles from the CBD than at serving those within 10 miles. Comparisons of actual traffic on light rail systems after they have opened with previous estimates made by those advocating them must be viewed with great care for two reasons.

• Those advocating such systems typically make two forecasts. One is a relatively high one made during the time when the city is deciding whether to adopt a light rail system. The second is a much lower one made after the decision to adopt has been made, but just before the system is put into operation. In most cases, actual ridership is much lower than the first estimate—the one relevant when deciding whether to adopt such a system—but may be higher than the second estimate. Defenders of light rail typically compare actual ridership figures with the second, lower estimate; opponents typically use the first, higher, estimate.

• Data concerning ridership are confusing because they often do not distinguish between boardings and trips. A person who boards a bus and then transfers to a light rail system has made two boardings, but only one trip. Data compiled as boardings tend to exaggerate the number of trips being made in any given period. In particular, many light rail passengers use both a feeder bus and light rail in making a single trip when they previously used only a bus—but that trip is then reported as two boardings rather than one.

When light rail systems are opened, transit authorities often greatly alter previous bus routes so as to coordinate with the new rail systems. For example, many direct long-distance bus routes are eliminated or transformed into feeder trips to light rail stations. Therefore, in order to evaluate the effects of a light rail system, it is vital to look at the overall number of trips made on buses and the light rail system combined, not just those on the light rail system alone. In some cities, the total number of trips on all forms of public transit has declined even though a significant number of persons are using the light rail system. Thus, total boardings on buses, heavy rail, and light rail systems combined fell from 1980 to 1995 in Baltimore, Buffalo, Denver, and Los Angeles, even though these cities opened light rail systems during that period.

Total ridership on buses and light rail can be greatly influenced by both overall transportation trends and specific fare changes. In the 1980s in general, national transit ridership increased about 8 percent; whereas it fell 14 percent in the first five years of the 1990s, according to the American Public Transit Association. Reductions in fares tend to increase transit ridership, while increases in fares reduce it, other things equal. Transit operators often influence ridership on light rail systems by making it more or less expensive than the bus alternatives available before the light rail system opened.

There is no persuasive evidence that light rail systems have reduced automobile traffic congestion or improved air quality anywhere, except in Denver. There routing most downtown-bound buses into a light rail terminal outside downtown and making passengers travel downtown on the light rail system have greatly reduced the number of buses passing through downtown each day. True, a notable percentage of light-rail commuters formerly drove to work. But their departure from key roads during peak hours has been offset by the entry onto those same roads in peak hours of an equal number of additional drivers who formerly traveled at other times, or on other routes.

Light rail systems cost more capital to set up than using “normal” buses, are not more efficient than buses in operating costs, and are less flexible in service quality than exclusive busways. Hence, from a purely economic viewpoint, they are not very advantageous.

Sources of Further Information
Web site of the Light Rail Transit Association.

Judy S. Davis and Samuel Seskin, “Effects of Urban Density on Rail Transit,” Land Lines, Volume 8,Number 3 (May 1996), the Lincoln Institute of Land Policy.

Anthony Downs, Stuck in Traffic (Washington, D.C.: The Brookings Institution, 1992).

Jonathan E.D. Richmond, New Rail Transit Investments—A Review (Cambridge: Alfred Taubman Center for State and Local Government in the John F. Kennedy School of Government at Harvard, June 29, 1998).

Don Pickerell, Urban Rail Transit Systems: Forecast Versus Actual Ridership and Cost (Washington, D.C.: Urban Mass Transit Administration, October 1990).

American Public Transit Association, Off Track: Response of the American Public Transit Association

³⁰ See Anthony Downs, Stuck in Traffic (Washington, D.C.: The Brookings Institution, 1992) 27-31. See also the NAIOP white paper entitled, “Coping with Traffic Congestion,” summarized in Appendix Three.

³¹ Judy S. Davis and Samuel Seskin, “Effects of Urban Density on Rail Transit,” Land Lines, Volume 8, Number 3 (May 1996), Lincoln Institute of Land Policy.