JUST as the famous choo-choo put Chattanooga on the map years ago, today this Tennessee River city is becoming a center for another mode of transportation: electric buses.
Nine of the city's 62 buses run on batteries, and seven more will be added this year, making it the largest fleet in the United States. Chattanooga is also home to the nation's only electric-vehicle test facility and one of only two electric-bus manufacturers.
Today fewer than 50 electric buses ply the streets of a handful of cities -- among them Santa Barbara, Calif., Denver, Savannah, Ga., Phoenix, Charlotte, N.C., Anderson, Ind., and Chattanooga.
While some experts question the cost and reliability of these quiet behemoths, advocates tout their advantages and say they will play a major role in America's urban mass transit.
''We know they work, we know they're clean, and people want more of them,'' says Joe Ferguson, president of Advanced Vehicle Systems Inc., Chattanooga's electric-bus manufacturer. ''Technology is so dynamic right now and moving forward so quickly'' the market for the buses is going to grow, he says.
Chattanooga began its experiment with electric buses in 1991, after city officials spent several years pondering how to transport tourists and workers through the city in a nonpolluting way.
Study done first
The Chattanooga Area Regional Transportation Authority (CARTA) asked Mr. Ferguson to study if it was feasible to use electric buses. He found it was and then formed a company to build the buses.
The vehicles run along a downtown loop that connects the Chattanooga Choo-Choo tourist site with the aquarium on the river.
Federal, state, and local funds pay for the $20-million project, which will eventually include 22 buses, recharging equipment, and three parking garages. Revenue from the garages will be used to pay for the cost of running the shuttle system, which is free.
Rick Hitchcock, CARTA chairman, calls Chattanooga's downtown shuttle route a ''living laboratory'' because it has become a national test site for the research, design, development, and demonstration of electric buses. Vehicle research consortiums, including a research-and-development arm of the military, are testing products such as batteries and motors on Chattanooga's buses.
The buses look similar to their diesel-fueled counterparts, but they are quieter, don't belch smoke, and weigh about 10,000 pounds less. They use electrically charged batteries that run about 75 miles before needing recharging.
Transit industry officials cite battery limitations as one of the biggest disadvantages of electric buses. But according to Ferguson, two new technologies soon to be tested on Chattanooga's buses could change that.
One would extend the range of the batteries to about 125 miles. Another device would enable batteries to be juiced up in 20 minutes instead of eight hours.
''I could easily see a growing number of local governments switching to electric buses once the bugs are ironed out,'' says Kenneth Orski, president of the Urban Mobility Corporation, a transportation consulting firm.
Mr. Orski points out, however, that some transit officials question the maintenance requirements electric buses put on transit agencies.
Still, Ferguson contends the maintenance costs on electric buses are about half that of diesel vehicles because they don't have a transmission or any exhaust, cooling, or fuel systems.
He adds: ''It costs about 6 cents a mile on electricity; diesel is about 16 cents a mile. You have to replace the batteries [on electric buses] every three to five years, but even then you still have lower operating costs.''
Ferguson sells a 22-foot battery-powered bus loaded with all the frills for about $165,000. In most cases diesel buses will cost about 10 percent more, he says.
Because the federal government's stricter emission standards are pushing public-transit authorities to find cleaner modes of transportation, the move toward electric buses will be a slow but continuing trend, says Jerry Trotter, director of bus technology at the American Public Transit Association.
But, he says, the transportation industry currently is focusing more attention on creating alternative fuels for diesel buses.