Drivers who use cellular phones while operating their vehicles are at an increased risk of crashing, according to a recent study commissioned by the Insurance Institute for Highway Safety (IIHS). The fourfold increase in crash likelihood was consistent among drivers, with male and female drivers experiencing similar levels of risk, as well as senior drivers and drivers under 30. The IIHS study underscores the need for 21st Century Insurance's (NYSE:TW) public safety billboards, which remind drivers to put down their cell phone and "Just Drive."

The study, which used cell phone billing records and interviews with crash victims to form the basis for its data, also found that generally, weather played a nearly non-existent role, and that there was no distinction between hands-free and hand-held cell phones. The study surveyed phone and accident records from drivers in Western Australia. Phone companies in the United States declined to share customer billing records, even with customer permission.

"This isn't intuitive. You'd think using a hands-free phone would be less distracting, so it wouldn't increase crash risk as much as using a hand-held phone. But we found that either phone type increased the risk," said Anne McCartt, IIHS Vice President for Research and an author of the study.

Another recent study by the National Highway Traffic Safety Administration showed that distracted driving also contributes to one in four traffic accidents.

In partnership with the Arizona Governor's Office of Highway Safety, 21st's "Just Drive" campaign encourages drivers to avoid common distractions such as using portable electronic devices, eating or talking on a cell phone while driving. Each board comprises a cartoon driver with headlines that read: "World's Deadliest Office," "World's Riskiest Restaurant," and "World's Most Dangerous Phone Booth." Additional billboards show drivers shaving, applying make-up or reading, and contain headlines that read: "World's Scariest Shaving Mirror," "World's Costliest Make-up Mirror" and "World's Dumbest Library."

"The results of this study clearly indicate that drivers should concentrate on the road when driving their cars," said Joyce Prager, Assistant Vice President of Community Relations, 21st Century Insurance. "That's why we encourage people to think twice before dialing and driving. It's important for all of us to avoid distractions while driving, focus on safety and to 'Just Drive.'"