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Derailing Illusions That Kill

Errors in perception, such as underestimating the speed of trains, add to danger at crossings, experts say. They propose remedies.

November 20, 2003|Patricia Ward Biederman | Times Staff Writer

In the United States, trains collide with vehicles 3,000 times a year, killing more than 300 people.

On Sept. 16, Benjamin Martinez of Orange became the sixth Southern California resident killed in such a crash this year when his Acura Legend was struck by a Metrolink train traveling at 90 mph through Santa Ana. According to some witnesses, Martinez, 29, speeded up just as the arm of the train's warning gate came down.

No one will ever know what Martinez was thinking in the seconds before the train slammed into him. But in almost every case, grade-crossing accidents such as Martinez's are blamed on driver carelessness.

In fact, it is a lot more complicated than that.

Scientists say that many of these accidents are caused by deadly misperceptions, the visual and behavioral quirks known to science but not to ordinary drivers. And making rail-crossing encounters even more treacherous are train and crossing designs that fail to take into account how people perceive and behave.

It's not enough to stop, look and listen at railroad crossings, these experts warn, because what you think you see can kill you.

"The attitude of the Federal Railroad Administration is that almost every accident that ever happened at a railroad crossing is the driver's fault," said cognitive psychologist Marc Green, a partner in the Toronto consulting firm Visual Expert.

One peculiarity of human perception is that large objects in motion appear to be moving more slowly than they really are. We can observe this phenomenon at any airport, said Herschel Liebowitz, emeritus professor of psychology at Pennsylvania State University. Jumbo jets appear to drift down to the tarmac during landings, while smaller jets seem to race toward the runway, even when the larger plane is going faster.

Liebowitz, who first described the size/speed effect and other grade-crossing perils in 1985, field-tested his theories by riding in the cab of a locomotive and questioning railroad personnel: "It was almost immediately obvious what the problem was.... People misestimated the speed of trains."

The problem is compounded by perspective.

When we look down a railroad track, we don't see the rails, or the telephone poles running along the tracks, as parallel. We see them converging in the distance at what artists and scientists call the vanishing point. As Liebowitz explains, we have learned to associate that apparent convergence with distance, and so we are likely to assume that the train is farther away than it really is.

Collisions also have what Liebowitz calls a "deceptive geometry" that can prove fatal.

Green explains the problem: Typically, you glimpse the train with your peripheral vision. Never as clear as central vision, peripheral vision is especially poor at gauging velocity. Even as the train moves toward you, and you move toward it, the train's image maintains a relatively constant position on your retina, at the edge of your visual field. The result: "You don't see it moving," Green said, and you assume it is still a safe distance away.

Then, when you are about to collide, the train's image on your retina suddenly expands in all directions -- a condition called looming. But at that point, you probably can't stop in time, and neither can the train.

By Green's estimate, perception -- or misperception -- is a factor in more than 80% of highway accidents, including those involving trains.

Many public officials charged with train-related safety are aware of the science of rail accidents but continue to take a Darwinian view of them.

"We know that the problem is there are just too many impatient drivers who fail to obey traffic regulations at either active or passive crossings," said Warren Flatau, a spokesman for the Federal Railroad Administration.

The tendency to blame the victim in grade-crossing accidents exasperates cognitive psychologist Green: "That lets the authorities off the hook. Then they don't have to redesign the system."

The United States has made progress in train safety, experts say.

"Railroad crossing deaths in the U.S. have come down from 786 in 1975 to 315 in 2001. That's a pretty good achievement, " said Eric Wigglesworth, an Australian accident researcher who won the Order of Australia -- comparable to British knighthood -- for his contributions to Australian public health and safety.

"I think this was largely due to the U.S. government's rail-highway crossings program which since 1978 has injected $4 billion into crossings improvements," Wigglesworth said.

The elimination of thousands of grade crossings and the increase in so-called active crossings, especially in heavily populated areas, have been important advances.

Twenty years ago, only about 50,000 of the country's 225,000 public grade crossings were protected by flashing lights, bells and/or gates that drop down when a train is about to pass. Today, there are about 62,000 of these active crossings out of 154,000.

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