You've heard of DWI. But the new traffic-safety issue is DWT, driving while texting.
The engineer of the Los Angeles-area train that killed 25 people when it crashed into a freight train Friday was sending text messages while on board, sources close to the crash investigation say. Officials still don't know how close to the moment of the accident the texts were sent.
Even as California prepares to vote Thursday on an emergency order banning train operators from using cell phones while on the rails, studies suggest driving while texting may be an even bigger issue on the nation's roads.
One in five drivers in a Nationwide Mutual Insurance survey admitted to texting while behind the wheel. And in another survey from FindLaw.com, a legal website, nearly half of drivers age 18 to 24 admitted to sending text messages, instant messages or e-mail messages while driving.
Law enforcement officials say it is nearly impossible to determine how many accidents are caused by texting because few drivers will admit to texting after being in an accident.
However, Donald Fisher, a professor of engineering at the University of Massachusetts at Amherst, said 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 University of Massachusetts engineers used a simulator to study what happened when people multitasked while driving. Special glasses fitted with a camera monitored what happened when drivers tried to sneak in a few messages on the road.
"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."
Only five states -- Alaska, Louisiana, Minnesota, New Jersey and Washington -- have laws specifically prohibiting texting behind the wheel. Twenty-one other states are considering passing similar legislation.
Gloria and Bob Wilhelm of Illinois are among those fighting for stricter regulation of mobile devices in cars after their son Matt was killed by a driver who was downloading ringtones.
"There's nothing worse than watching my son die before my very eyes," Gloria Wilhelm said. "I think people totally overestimate what they can do while they're driving."
She added that education is not enough.
"People can hear all the statistics they want," she said. "But unless there are severe penalties -- financial penalties or revoking licenses if the accidents are severe enough -- that behavior won't change."
Other people say laws against texting are not the answer and that the drive for such rules is just the latest example of too much legislation.
"There is a point where we actually have to trust the American people to have a certain amount of common sense," said Katherine Mangu-Ward, associate editor of Reason magazine. "When they first put radios into cars, we had this exact same debate: How could people possibly handle adjusting their radio dial while driving?"
"Turns out we get used to certain things," she added. "We get better at them. I think texting will fall in that category, eventually."