Atlanta -- More than half of high school seniors admitted in a government survey that they've texted while driving.
It's the first time the question was asked in a teen poll on risky behavior, and the finding comes amid a renewed federal crackdown on distracted driving.
Texting and cell-phone use behind the wheel is "a national epidemic," Transportation Secretary Ray LaHood said Thursday.
"We need to teach kids, who are the most vulnerable drivers, that texting and driving don't mix," LaHood said at news conference to announce pilot projects in Delaware and California to discourage distracted driving.
In the survey, about 58 percent of high school seniors said they had texted or e-mailed while driving during the previous month. About 43 percent of high school juniors acknowledged they did the same thing.
The findings released Thursday are the first federal statistics on how common the dangerous habit is in teens. Distracted-driving deaths are most common in teens, blamed for about 16 percent of teen motor vehicle deaths.
Focusing on a cell-phone instead of the road leads to delayed reaction times, lane swerves and other lapses with sometimes fatal consequences, experts say.
Thirty-nine states ban texting for all age groups, and an additional five states outlaw it for novice teen drivers. And authorities are increasingly cracking down. In the last two weeks, teens in Missouri and Massachusetts have been sentenced to jail - one for a year - for fatal accidents involving texting.
For the survey, the Centers for Disease Control and Prevention last year questioned more than 15,000 public and private high school students across the country.