Texting while driving in the U.S. increased 50 percent last year, according to the National Traffic Safety Administration.

The agency revealed the statistics Thursday, claiming that two out of every 10 drivers says they have sent text messages or emails while driving. The statistics are alarming, in part, since many states have tried to tackle the issue with new laws to ban texting or messaging while driving. After a Pennsylvania law went into effect, 35 states now have laws against texting while driving.

A spokesman for the Governors Highway Safety Association in Pennsylvania said the increase in texting while driving is a concern.

It is clear that educational messages alone aren't going to change their behavior, Adkins told The Associated Press. Rather, good laws with strong enforcement are what is needed. Many drivers won't stop texting until they fear getting a ticket. The increase shows what an uphill challenge distracted driving remains.

NHTSA conducts an annual snapshot of driving behavior via stakeouts at selected stoplights and intersections where drivers are counted who use cell phones and other hand-held Web-based devices while behind the wheel.

From the 2010 study, activity of people surfing the Internet, sending text messages and other mobile communication activities increased in the most recent survey to 0.9 percent of all drivers, up from 0.6 percent the previous year.

The survey also found that most drivers will answer a phone call while driving and most will continue to drive after answering. 

In a different survey, this one conducted by telephone, the NHTSA found that 18 percent of all drivers said they have sent text messages or emails while driving. The survey was conducted among 6,000 drivers aged 18 or old. Among those, nearly half of the participants aged 21 to 24 years old said they have texted or emailed while driving.