CARMICHAEL, Calif. -- On a peaceful early morning in February 1991, a fiery gasoline-tanker crash jolted this Sacramento suburb like a terrorist car bomb.
Incredibly, no one died. But property damage spread for blocks.
A computer analysis by the Los Angeles Times, using accident reports from the U.S. Department of Transportation, shows that in the past 10 years well over half the deaths and almost half the property damage from major hazardous-material accidents on the nation's highways was caused by gasoline tankers.
A loaded gasoline truck generally carries fuel with a maximum potential energy equivalent to about 100 tons of TNT -- enough to level several city blocks.
Although the federal government has moved to increase tanker safety in recent years, the Times found that these trucks remain a serious potential menace:
* They are imperfectly designed. Their tanks are built high off the ground to limit the risk of damage to the pipes underneath. But that makes the trucks top-heavy. With a high center of gravity and a narrow wheelbase, scores of tankers roll over in serious accidents every year.
* Driver error is a major problem, accounting for up to two-thirds of all tanker accidents. Tankers traveling too fast around a curve are disasters waiting to happen.
* Tankers are especially vulnerable to the unexpected. The few seconds following a blown tire or brake failure can turn into life-and-death dramas. Thin aluminum tanks are readily punctured in accidents. A tanker pulling a trailer can be hard to control in an emergency.
With few restrictions on its transport, gasoline accounts for about half the nation's hazardous-materials shipments. Though the vast majority of gasoline tankers deliver their product safely, the fraction that does not poses a significant threat.
"There is no question that these trucks roll over with greater frequency [than other vehicles] and when they do, horrible things can happen," said David R. Pesuit, a veteran highway accident investigator in Northampton, Mass.
From 1982 to 1991, gasoline truck accidents killed 52 people, injured 79 and forced the evacuation of 1,648 people, according to U.S. Department of Transportation accident reports. The true toll is far higher, safety experts say, because major gaps exist in the government's data.
Defenders argue that gasoline tankers are much safer than they used to be and have excellent safety records -- if they are driven carefully and well-maintained. Some accidents are simply unavoidable in a petroleum-addicted nation that consumes more than 300 million gallons of gasoline a day, the trucking industry contends.
The Times study found a steady increase in hazardous-materials incidents on the nation's highways during the past 10 years, with the annual tally of spills climbing 34 percent from 1982 to 1991.
Still, given the volume of liquids hauled, some front-line law enforcement officials argue that the roads are getting safer, as trucking companies pay increased attention to equipment maintenance and driver training.
A new nationwide commercial driver's license requires special tests for those who haul hazardous materials. Other federal rules, which take effect next year, aim to improve tank manufacture and maintenance. The goal is to avoid spills when a serious accident occurs.
Skeptics, though, say the new rules are confusing and question if they will make a difference.