How many times have you seen some boneheaded driver make a stupid move on the road, only to drive up beside them and see them yapping away on their cell phones? Too many times, I'll bet you. Now a new study shows that cell phone users also drive more slowly and make poor lane-change choices, which may slow down traffic overall up to 10%. From the LA Times:

Researchers at the University of Utah have found that motorists jabbering on cellphones drive more hesitantly than undistracted drivers and, as a result, are increasing everyone's average drive time by 5% to 10%.

For someone with an hourlong commute each way, that translates into as much as 12 extra minutes behind the wheel each day, said psychologist David Strayer. Over the course of a year, the excess time in traffic could easily top 50 hours -- more than a typical week in the office.

Basically, drivers who aren't paying attention cause drivers around them to slow and stop more often, which sends a "shock wave" effect through the rest of traffic. Once everybody's stopped, it takes a lot longer to get up to a normal speed again, thus causing the "stop-and-go" conditions that send every single one of us into unhealthy fits of impotent rage.

Using a cell phone while driving also quadruples your chance of getting in an accident -- hey, you might as well be driving drunk. The study did not indicate if driving with a Bluetooth or other hands-free equipment would affect driving conditions, or if text-messaging was equally dangerous. The lesson is pretty clear here, though -- if you want to get there faster, get off the phone and pay attention to the road.

Photo by andropolis via Flickr