Smart phones are a growing source of driver distraction, but researchers hope to use their capabilities to make the devices' use less dangerous. New sensing technology can determine whether a phone is being used by the driver, or merely a passenger, and is providing a building block for a new generation of distraction-thwarting apps.

Research shows that just talking on a phone increases the risk of a crash four times; texting increases it 23 times. The National Transportation Safety Board (NTSB) recently called for a nationwide ban on driver use of cell phones and other portable electronic devices while driving, and said that electronic devices were a factor behind an unknown number of the more than 3,000 distraction-related deaths on U.S. roads in 2010.  

Some existing phone-blocking tools, such as a $20 per year service from iZup, use a smart phone's GPS receiver to tell when it's being used inside a moving vehicle, and then automatically send calls to voice mail and delay text messages. Some "driver mode" apps available in Android Market do things like change the interface to feature bigger and fewer buttons on the screen and limit available apps to ones like navigation. And a few wireless carriers offer distraction-fighting services, too.

But these apps have an Achilles' heel: they are based on detecting car motion. That means that within the car, they can affect not only drivers' phones but those of passengers, who are present in 38 percent of vehicle trips.

Researchers from Rutgers University and the Stevens Institute of Technology are developing technology that determines when a phone is likely in the driver's area. It uses the phone to connect with a car's stereo system via Bluetooth and issue subaudible beeps inside the car. The phone's microphone picks up the beeps; a signal-processing algorithm calculates the position of a phone within the car.

 "We like to find some middle ground—try to reduce the driver distraction caused by phone use, but let the driver decide whether they want to use the phone or not, or use it in a safer way," says Yingying Chen, a computer scientist at the Stevens Institute of Technology. Chen codeveloped the technology. "We have put all the pieces together so you can get into a car, and when this application runs, it will decide whether you are the driver or the passenger."