Train design that can save lives still rarely used; Southern California crash shows benefits

Technology that can blunt the tremendous force of a head-on collision appears to have paid off in the remarkably low number of serious injuries suffered when a Southern California commuter train slammed into a truck abandoned on the tracks.

And yet very few commuter train systems in the U.S. have this "crash energy management" technology.

Metrolink began investing heavily in new passenger cars with the technology after a 2005 crash that killed 11 people. Three of the four cars in Tuesday's accident had the new design, which disperses the energy of a crash away from where the passengers sit.

For years, federal regulators have weighed rules that might require such technology. But they have not formally proposed such measures.