Text messaging while driving makes drivers six times more likely to crash, according to a new study. The findings indicate that the practice is much more dangerous than talking on a cell phone while driving is.

The study by researchers at the University of Utah, employed a driving simulator and used 40 young men and women as drivers. All were both veteran texters and drivers who were comfortable performing each task. Perhaps too comfortable.

The researchers found that texting while driving decreased reaction time 30%, while talking on a cell phone decreased reaction time only 9%. This does not mean that using a cell phone while driving is safe...

Those who combined texting and driving had more crashes, left less distance between themselves and the car ahead of them, had decreased reaction times, were slower to respond to brake lights on cars in front of them and generally had less control of their car. In short, they were exactly the type of driver you go out of your way to avoid.

Much has been made recently about the dangers of using a cell phone while driving. The researchers found that texting while driving decreased reaction time 30%, while talking on a cell phone decreased reaction time only 9%. This does not mean that using a cell phone while driving is safe; it means that texting while driving is considerably more dangerous.

The researchers also found evidence that drivers are partially able to deal with the distraction of talking on a cell phone by dividing their attention between the two tasks, adjusting the amount of attention spent on each according to their moment to moment difficulty. But texting while driving requires a switch of attention between two different visual tasks, not a splitting of attention, meaning that some of the time, drivers are paying zero attention to the road, with predictable results. In the study, reading text messages was more distracting than composing them was.

A number of U.S. states and cities already have laws in place that make it illegal to text while operating a vehicle. This study helps to show the wisdom of these laws. Many studies have previously shown that using a cell phone while driving is dangerous. This study suggests that texting is much worse.

How many text messages are so important that they can't wait until you're off the road?

An article on the study was published online ahead of print by Human Factors: The Journal of the Human Factors and Ergonomics Society on December 16, 2009.