Police Radar Gun
Police will be able to use radar guns like this to see if drivers are texting Creative Commons

A radar gun-like gadget that can detect when drivers are texting is being developed by US company ComSonics.

The device picks up on radio frequencies that are emitted when a mobile phone is being used.

Once it has been tried and tested, the detection technology will be provided to roadside police in the US.

Speaking at the second Annual Virginia Distracted Driving Summit, Malcolm McIntyre from ComSonics compared the technology to that which cable repairmen use to locate frequencies leaking a transmission.

Using the radio signal emitted from the vehicle, the ComSonics device can decipher what type of phone activity is going on behind the wheel, with distinguishable frequencies for texts, phone calls and also data transfers.

McIntyre said the device is "close to production" but still has steps to take, including legislative approval and adoption by law enforcement.

But the major hurdle is figuring out how to identify which phone is being used from within the car - the driver's or a passenger's. Perhaps, as a way around this complication, authorities will only stop cars with one driver.

ComSonics, based in Virginia, started in the cable TV industry – thus the analogy – and provides calibration services for speed enforcement equipment.

Texting while driving is dangerous, and is banned in many parts of the US, including ComSonics' home state.

In the UK, drivers caught using a mobile phone will be fined anywhere between £100 to £1000 depending on whether they are taken to court. You can also lose your license to drive.