PLACENTIA, Calif. -- Despite the first passenger deaths Tuesday in Metrolink's fairly short history and a fatal Amtrak wreck in Florida last week, rail is still the safest way to travel on the ground, the San Bernardino County Sun reported.

“Overall, railroad safety has improved rather dramatically over the past decade,” said Warren Flatau, a spokesman for the Federal Railroad Administration. “Accidents on this scale are infrequent on passenger trains.''

But for at least three decades, regulators have been pushing to make that record even better with an automated safety system that would stop a train if something were in the way, a system that is only recently being tried in the East.

In 2001, 962 people were killed in rail accidents, according to FRA statistics, but the vast majority of those involved trains hitting cars, trucks or pedestrians. Only three passengers on trains were killed last year.

That passenger death total was doubled in the past week with the two who died Tuesday in Placentia and the four who were killed Thursday when 40 cars of an Amtrak train jumped the tracks in Florida.

More than 40,000 people a year are killed in cars and trucks. The 416-mile, 10-year-old Metrolink system, which serves more than 32,000 passengers daily, will carry its 50‚millionth passenger some time this year, said spokesman Francisco Oaxaca.

The Inland Empire-Orange County line, which runs from Riverside to San Juan Capistrano, is the fastest growing line in the system. In January, it carried an average of 2,930 passengers a day.

The San Bernardino-Los Angeles line, which does not share tracks with freight trains, carries about 10,000 passengers per day. The growth in both freight and commuter traffic should pose no safety problem on the Inland Empire route, Oaxaca said. Twelve Metrolink trains per day use the route along with about 55 freight trains.

“We're not in any situation where it's like gridlock on the freeway,” Oaxaca said. “It's not an issue of running out of capacity.”

Still, regulators have been pushing since at least 1970 for a system that would take human error out of the equation and prevent train crashes.

The positive train control system has been on the National Transportation Safety Board's most-wanted list since 1990. An automated system that would apply the brakes of a train if another train or obstacle were in the way “would prevent an accident like the one that occurred” Tuesday, said John Bentley, a spokesman for the Brotherhood of Locomotive Engineers.

Technology and cost are the major impediments to such a system, but after each major rail accident involving human error, the NTSB has stepped up its demands that automated safety systems be installed where freight and commuter trains share the rails.

The NTSB has no regulatory authority over the railroads, however. Some automated safety systems have been tried on the busier rail lines in the East, but the FRA has declined to require similar systems nationwide.

In a March 2001 response to the NTSB's recommendations, the FRA stated it cannot require all major rail lines to install such systems “- since to do so would require equipping thousands of freight locomotives - a cost that wold financially overwhelm the passenger railroads.”

But work continues on developing and deploying an automatic safety system.

“The Federal Railroad Administration believes positive train control has the potential to greatly increase railroad safety and efficiency, and we are working in partnership with the railroads and other stakeholders to implement such a system,” Flatau said.

The tracks on which Tuesday's crash occurred are owned by the Burlington Northern and Santa Fe Railway Co. and are controlled by the railroad's dispatch center in San Bernardino.

There is no way to tell yet if the crash was the result of a dispatch error, an error by the crews on one of the two trains, or a mechanical failure, officials said.

A number of accidents have been caused when a train crew proceeds through a red light and winds up on the same track with another train. Fatigue among rail crews is another issue being examined by federal regulators, Flatau said.