SOME argue that light rail would reduce traffic congestion and, as a result, reduce air pollution in Houston. They are willing to spend billions of the taxpayers' hard-earned dollars in order to prove that point. But there is plenty of evidence to suggest that such an investment is not worthwhile, that the taxpayers of Houston will not get their money's worth when it comes to light rail. 

We need to be very careful before we commit the people of Houston to light rail. Three questions need to be answered before we move forward on this project: 

• Has it worked elsewhere? The evidence is pretty discouraging. In Portland, Ore., traffic volumes on the adjacent freeway are up 70 percent since before light rail opened. Even 12 years after opening, Portland's light rail carries a third fewer riders than were projected after five years. In Buffalo, N.Y., ridership fell 68 percent short of projections, and overall transit ridership is less than before light rail. In Los Angeles, over the past 13 years transit ridership has dropped 25 percent. During that period, Los Angeles and the nation's taxpayers have spent more than $5 billion to open two light-rail lines, a subway and six commuter-rail lines. But annual debt since exceeds bus and rail-fare revenues, and will increase to $400 million by 2004. Construction of three lines on which more than $300 million has been spent has been put on hold indefinitely. An organization representing Los Angeles' large low-income transit-dependent population has successfully argued that funding is inappropriately being taken from fare increases and bus-service reductions to fund rail construction. 

• Is there evidence that it will work in Houston? Texas Transportation Institute data indicate that traffic congestion has not been reduced in any city that builds rail. On the other hand, TTI's data show that traffic congestion has declined in two cities - and one of them is Houston, where we have continued to build highway capacity. Ridership on the Dallas Area Rapid Transit system is above projections. But is it taking cars off the road? In fact, ridership on DART's directly operated bus and light-rail services is up only 15 percent since before light rail. (This is estimated using passenger miles, which counts riders based on their entire trip, rather than based on each leg of their trip to artificially inflate the data.) Since transit's share of travel in Dallas County is less than 2 percent, this means that, at most, light rail has attracted a minuscule “0” percent of travel. Moreover, even with the 15 percent increase, ridership remains at least 5 percent below 1991 levels. 

• What about benefits to the environment? Based on figures from the North Central Texas Council of Governments, estimates show that DART rail lines will likely reduce air pollution in the region by approximately 0.0001 percent. 

• Is it worth the cost? U.S. Department of Transportation research indicates that busways are one-fifth the cost of light rail per passenger to build and operate. Busways can carry as many riders as light rail and as fast. Yet, almost without exception, other cities have chosen rail. 

All of this has not prevented local civic and transit officials from declaring their systems a success, as if success consists of the construction alone. But a successful rail system is more than a monument to taxpayer funding and it must do more than swell the beasts of its promoters for whom, all too often, meaningful reduction of traffic congestion is less than an afterthought. 

Does all of this mean that we should not build rail in Houston? No. But it does mean that we need to do a much better job of planning and reviewing the alternatives than other cities have done. And the review must be objective. Any analysis should include a healthy bus alternative - one with service levels as high as proposed for rail, and with dedicated rights of way. It should also include an alternative that would allow competitive contracting to the private sector, which the Metropolitan Transit Authority has used successfully on some services to reduce costs. 

I have great hopes for Houston. Metro has already shown itself to be a leader. During the 1980s, Houston was one of only two U.S. cities where the percentage of people using transit to get to work increased. It declined in all the cities that built rail. 

For example, Portland's light-rail bravado ignores a 35 percent fall in the percentage of people taking transit to work. In contrast, during the 1970s prior to building its light-rail system, Portland relied on bus-fare reductions and bus-service expansions to attract riders, and the percentage of people using transit to get to work increased. In Houston, bus ridership has increased significantly, though at a much slower rate than traffic volumes. 

Whether we build rail should depend upon three criteria. 

• The first has to do with reducing traffic congestion. Rail's success is not demonstrated by the number of people on the train, rather it is demonstrated by how many cars it takes off the road. The number must be material.

• The second test is financial - that whatever rail accomplishes, it should do so for less than any other alternative. 

• And the third criteria is just as important - that the alternative finally selected must be the result of objective and rigorous planning and studies, whose design and processes are not skewed for or against any of the alternatives.