But now a new report by the United States Government Accounting Office (GAO) is causing ripples throughout the U.S. public transit industry. Confirming the work of Kain and his colleagues, GAO found that:

• Light rail is 2.5 times as expensive to construct as bus rapid transit (BRT) in its most expensive configuration, exclusive bus freeway lanes (Figure).

• Light rail is nearly four times as expensive to construct as bus lanes that also serve as high occupancy lanes.

• Stunningly, that light rail is more than 50 times as expensive to construct as bus lanes on arterial streets. This is an important finding, because arterial bus lanes have great promise. Curitiba, Brazil has pioneered an arterial street bus lane system that carries at least six times the hourly volume of the best US light rail line.

• In all configurations combined, light rail is 3.7 times as expensive as BRT to build.

Perhaps the most damaging finding from the perspective of the rail lobby, however, is that, all things being equal, BRT operating costs are less than light rail. For years, the rail lobby has been claiming that light rail operating costs are lower than bus costs. This is a statistical artifact, however, because such figures always include the very low ridership bus lines, rather than comparing comparable high volume bus routes. On average, GAO found that operating costs per passenger were 2.3 percent lower for BRT. If the system wide averages of the transit systems studied are considered, the gap is even greater. Light rail operating costs per passenger mile are nearly 50 percent higher than that of BRT.

But this is just the beginning. Because of light rail's prohibitive capital costs, BRT enjoys and even greater advantage in overall cost per passenger mile. It is estimated that light rail operating and capital costs per passenger mile are $3.16, nearly three times that of BRT at $1.08 (Figure).

Then there is the matter of speed. A number of transit authorities have incorrectly labeled light rail as "rapid transit." But, because of its operation without grade separation from street traffic, light rail is often little faster than buses. GAO found the average LRT operating speed to be 16.8 miles per hour. BRT was nearly double that, at 32.2 miles per hour (Figure).

Given the spread out nature of American cities and the highly dispersed patterns of travel, there is good reason to question the extent to which transit might be a realistic alternative to the automobile for all but a small percentage of trips. That does not mean, however, that the money spent on transit should not be used to maximize its benefits. The GAO report confirms what many have known for a long time. If buses systems are designed to the same standards as light rail systems, they can attract just as many riders, at a fraction of the cost. This, in the end, means more transit, whic h is the very purpose of public subsidy.