Using a cellphone while driving increases crash risk. There is growing evidence that talking on a cellphone increases crash risk, though the connection hasn't been firmly established. Researchers have consistently linked texting or otherwise manipulating a cellphone to increased risk.

Cellphones and texting aren't the only things that can distract drivers. The National Highway Traffic Safety Administration defines distracted driving as any activity that could divert attention from the primary task of driving. Besides using electronic gadgets, distractions can also include adjusting a radio, eating and drinking, reading, grooming, and interacting with passengers. The crash risk associated with these other activities isn't well established.

It's not clear that banning hand-held phone use and texting reduces crashes. This is the case even though IIHS research has documented that bans on hand-held phone use reduce overall phone use. Crashes have increased in recent years, but overall cellphone use has not. Drivers are distracted by things other than cellphones, so prohibiting phone use will not eliminate distracted driving. Broader countermeasures that keep drivers from becoming distracted or that mitigate the consequences of distracted driving, such as crash avoidance technology, may be more effective than cellphone bans.