New technology will help UK police find drivers who use their phones while behind the wheel. Mobile phone detectors will be used by the Thames Valley and Hampshire police forces in an effort to reduce the number of deaths and accidents caused by distracted drivers on cell phones.

The technology features a sign that can detect there is a phone being used in the car, and will flash a signal telling the driver to pay attention and get off the phone. The only problem is the detector isn’t able to tell whether the phone is being used by the driver or a passenger.

Police hope the sign encourage motorists to put the phone down and that it will lead them to areas where phone use is most common. The sign will not be used as an “enforcement tool”.

The sign cannot record drivers, but it does pick up 2G, 3G, and 4G signals and will flash at drivers to remind them to put their phones down. While the police admit it isn’t a perfect solution, they hope it will increase awareness about the dangers of mobile phone use and lead to less accidents in the future.