LOS ANGELES -- Freight and passenger rail traffic is projected to sharply increase in coming years across the Los Angeles region, and with it, some fear, the number of delays and accidents, according to a wire service report.

On Tuesday, a Burlington Northern Santa Fe freight train failed to stop at a signal and slammed into Metrolink commuter train in Orange County, killing two passengers and injuring nearly 270.

The accident took place on a stretch of rail owned and operated by Burlington, but shared by about 70 freight, Amtrak and Metrolink trains each day.

Although rare in places like Europe, that type of arrangement is typical throughout the nation. Amtrak, for example, operates its passenger trains almost exclusively on freight lines outside of the Northeast.

Because they share the rails, American passenger rail cars are the most crash-worthy in the world, said Warren Flatau, a spokesman for the Federal Railroad Administration.

In Southern California, experts predict the number of trains plying the region's tracks to jump soon. More freight will make its way to and from the nation's busiest port complex by rail and more workers will choose rail over the region's congested freeways, officials predict.

Together, the increased traffic will further tax an already burdened rail network.

"The projections are pretty scary," said Jeff Lustgarten, a spokesman for the Southern California Association of Governments.

Today, about 140 trains travel each day between downtown Los Angeles and San Bernardino, 64 miles to the east, according to SCAG estimates.

That number could jump to 265 by 2010, and to 390 by 2025.

Until Tuesday's accident, rail officials were most concerned with delays on the shared tracks.

Just last month, Metrolink put Union Pacific Railroad on notice that its dispatching practices were causing regular delays of 30 to 120 minutes to its commuter trains. Metrolink leases track rights from both Union Pacific and Burlington.

With Tuesday's accident, officials stress that safety is also at stake.

Hal Bernson, a Los Angeles city councilman and chairman of the Metrolink board, said he has lobbied, largely to no avail, for state and federal funding to add tracks to the commuter line's routes.

"If we had had double tracking, this could have been avoided," Bernson said of Tuesday's accident.

Rail collisions in California have been on the rise in recent years, according to the California Public Utilities Commission, which oversees rail safety. There were 183 train-to-train collisions in the state in 2000, a 75 percent increase since 1997, said CPUC spokeswoman Sheri Inouye.

Mike Furtney, a Union Pacific spokesman, said more tracks will ease the problem, but that it required compromise as well.

"You can't just comfortably or easily impose a busy commuter rail system on a very busy freight rail system without some give and take from both sides," Furtney said.