It didn't take the full two months of training for Bob Myers to recognize the greatest fear of all Baltimore light-rail operators.
"Howard Street," he says without hesitation.
In the chaos of a city street, cars and pedestrians, traffic lights and parked delivery trucks test his reaction time. Anything can happen. And, as the former bus driver observes, Baltimore's new two-car light-rail trains weigh 107 tons -- about the same as a Boeing 747 jumbo jet. They "do not stop on a dime."
"At least in a 747 there'd be someone sitting next to me, a co-pilot with a second pair of hands," said Mr. Myers, a Catonsville resident and 28-year transit veteran. "It's an awful lot of responsibility."
When the first 13-mile segment of Baltimore's Central Light Rail line opens full time next month, there are bound to be accidents. Judging from the experience of similar systems in the nation, they're most likely to occur where the trains share the road with cars and pedestrians.
In the first two months of testing, light-rail trains have collided with cars twice in the downtown area. Both incidents involved minor damage and were the fault of inattentive motorists.
"It comes from being human -- occasionally someone's going to screw up," said Lawrence M. Engleman, safety director for the Mass Transit Administration. "If people pay attention to a traffic light, it's not a problem. Unfortunately, people not paying attention to a light is how accidents usually happen."
A recent study by the Federal Transit Administration found that light-rail systems experience about three accidents every 100,000 miles driven, an accident rate 100 times worse than subway trains.
Transportation planners say this is part of the trade-off state government made four years ago when Gov. William Donald Schaefer proposed building the $446.3 million system to link Timonium to Glen Burnie through downtown Baltimore.
Light rail is faster to build and cheaper than a subway. By way of contrast, Baltimore's 9-year-old Metro subway system cost $1.32 billion for 15.5 miles, including the 1.5-mile extension to Johns Hopkins Hospital that is still under construction. But light rail is also slower and has a smaller capacity.
Subway systems have an exclusive right of way; light rail does not. As a result, there are far more opportunities for collisions.
"By the nature of light rail, there's lots of grade crossings, and people and automobiles have to become acquainted with and have respect for a train," said Frank J. Cihak, chief engineer for the Washington-based American Public Transit Association. "People don't step out in front of moving automobiles but they will step in front of light-rail trains with great frequency."
In other light-rail systems -- there are about 20 in the United States and Canada -- the consequences have sometimes been disastrous. In Los Angeles, six people have been killed in accidents since the 22-mile-long Blue Line to Long Beach opened in July 1990.
The San Diego Trolley, one of the nation's first modern light-rail systems, still experiences about 3 1/2 accidents each month, a spokesman said. Since July, the 34-mile-long light-rail line has recorded 33 collisions with cars, and the trains have hit at least five pedestrians.
Even in Pittsburgh, where light-rail trains have their own underground tunnel through the downtown area, there have been safety problems. The 22-mile-long system recorded 32 accidents in 1990 but has seen no fatalities since its opening in 1985.
"We've had problems," said Harry Saporta, manager of safety for MAX -- the Metropolitan Area Express system in Portland, Ore. "In terms of safety, the downtown was the challenge and we had to make changes. A train just can't stop as quickly as a car."
Part of the problem, experts have found, is that the electric trains areso quiet, motorists sometimes don't realize they're nearby despite their horns and bells. Accidents frequently happen at intersections when drivers veer their cars into tracks to make a turn or stretch a light.
In Los Angeles, the most serious safety hazard has turned out to be at grade-level crossings where roads intersect the train's right of way.
Motorists stopped at such crossings would sometimes see a slow-moving Southern Pacific freight train but not the speedier light-rail train running alongside and try to get around the lowered barriers.
"When these accidents happen, everybody shakes their heads and goes, 'Tsk, tsk,' " said Greg Davy, spokesman for the Southern California Rapid Transit District, which operates the Blue Line. "All we can do is try to get the message out to people. It's like a child that keeps misbehaving."
MTA officials in Baltimore are spending $100,000 to educate elementary school students along the light-rail route about how to use the system and recognize the dangers of everything from trains moving almost 60 mph to the overhead wires that carry a 750-volt charge.