SANTA CLARITA, Calif. --- In response to last Friday's chain-reaction crash on Interstate 5 that killed three people, the California Department of Transportation is examining why the speed limit for the tunnel was raised several years ago from 45 mph to 55 mph. Douglas Failing, Caltrans district director for Los Angeles and Ventura counties, told the Los Angeles Times he has called for a "geometric analysis" of the road and 550-foot tunnel where the deadly accident occurred to determine the proper speed for trucks. Failing has directed his staff to investigate the reasons behind the speed limit changes over the years since the bridge was built in the early 1970s. Transportation officials are also exploring ways to make the bridge safer. Truckers have complained that this section of highway is particularly dangerous because lighting in the tunnel is dim and the road outside the tunnel curves, the L.A. Times reported. A truck carrying coffee beans and other goods triggered the pileup last Friday night when the truck lost control and caught fire.