The UK is testing out a new system that will detect whether or not a mobile phone is being used in your car and it will flash a sign at you. Next week in the UK, automatic ticket writing systems will go into effect. Seriously, the system is looking to simply be a deterrent at this time since it cannot tell the difference between a driver or passenger. "The system cannot differentiate between a driver and the passengers on a bus, for example, but this goes some way towards remotely warning drivers that they can be detected using their phone." Using a directional antenna, the detector picks up radio waves emitted from a phone handset, and measures the signal strength and length of activation. When a signal is detected of a duration and signal strength sufficient to activate the system, the detector triggers the sign. The detector is able to distinguish Bluetooth connections which, when picked up, will prevent the trigger activation.