WASHINGTON - For all the criticism and new legal bans, texting by drivers keeps increasing, especially among younger motorists.

About half of American drivers between 21 and 24 say they have thumbed messages or e-mailed from the driver's seat. What's more, many drivers don't think it's risky when they do it - only when others do.

A national survey, the first government study of its kind on distracted driving, and other data released Thursday by the National Highway Traffic Safety Administration underscore the difficulty authorities face in discouraging texting and cellphone-talking while driving.

At any given moment last year on America's streets and highways, nearly one in every 100 car drivers was texting, e-mailing, surfing the Web, or otherwise using a handheld electronic device, the safety administration said. Those activities spiked 50 percent over the previous year, even as states rush to ban the practices.

Last month, Pennsylvania became the 35th state to forbid texting while driving.

In 2010 there were an estimated 3,092 deaths in crashes affected by a wide range of driver distractions, from eating meals to thumbing e-mail, the NHTSA said. That number was derived using a new methodology aimed at getting a more precise picture of distracted driving and can't be compared with previous years, officials said.

The agency takes an annual snapshot of drivers' behavior behind the wheel by staking out intersections to count people using cellphones and other devices, as well as other distracting behavior.

While electronic gadgets are in ever greater use by drivers, motorists are deeply conflicted about it, a NHTSA survey of more than 6,000 drivers found.

Most said they would answer a cellphone call while driving and continue to drive after answering. And nearly two of 10 acknowledged sending texts or e-mails from behind the wheel. That spiked up to half of drivers 21 to 24 years old.

More than half of drivers said making a cellphone call made no difference to their driving performance, and a quarter said texting or e-mailing made no difference. But 90 percent said that when they are passengers they feel very unsafe if the driver is texting or e-mailing.

Indeed, big majorities of drivers surveyed support bans on handheld cellphone use and texting while driving - 71 percent and 94 percent, respectively. Most said they wanted people who violate the bans to be punished with fines of $100 or more. Almost a quarter support fines in the $200-to-$499 range.

"Everyone thinks he or she is an above-average driver - it's all the nuts out there who need educating," said Russ Rader, a spokesman for the Insurance Institute for Highway Safety.