LOS ANGELES --- Last Friday's catastrophic train collision in Chatsworth, CA, which killed 25 and injured 135, has served to place a spotlight on safety hazards that affect not only trains but vehicles as well.

Federal investigators have told the Los Angeles Times that records from Metrolink engineer Robert M. Sanchez's cellphone show that he sent and received text messages while on duty the day of the collision. However, investigators have not yet determined whether he was texting at the time of the collision.

What's more, federal investigators are trying to determine whether Sanchez's back-to-back, split-shift workdays, which began before dawn and ended at 9 p.m., played a role in the tragedy.

As any vehicle fleet manager knows, drowsy driving and texting behind the wheel are major safety risks.

A Nationwide Mutual Insurance survey found that one in five drivers admitted to texting while behind the wheel. In another survey from FindLaw.com, a website for the legal community, nearly half of drivers ages 18-24 admitted to sending text messages, instant messages or e-mail messages while driving.

Law enforcement officials told ABC News that it's nearly impossible to determine how many accidents are caused by texting because drivers rarely admit to texting after they're involved in an accident. But Donald Fisher, a professor of engineering at the University of Massachusetts at Amherst, told ABC News that the risk of crashing while texting is "in the neighborhood of the crash risk when you've had three to four drinks of alcohol."

Fisher and other engineers at the university used a simulator to study multi-tasking drivers. Special glasses fitted with a camera monitored the drivers while they texted.

"Most people think they can get away with typing out some quick phrases while they're driving," Fisher said. "But our research shows if you look away from the road for just a few seconds it nearly triples your risk of crashing."

Alaska, Louisiana, Minnesota, New Jersey and Washington all have state laws that specifically prohibit texting behind the wheel, ABC News reported.

Another study, conducted by the RAC Foundation in the U.K., tested drivers ages 17-24 and found that reaction times deteriorated by an average of 35 percent when the drivers were texting, BBC News reported. This study also used simulators.

"We need to ensure that text devotees understand that texting is one of the most hazardous things that can be done while in charge of a motor car," RAC Foundation Director Stephen Glaister told BBC News.