This week, three new £6,000 road signs were introduced in Norfolk to detect and deter drivers from using mobile phones whilst driving. The new signs reportedly detect both the signals of a mobile phone engaged in a call, as well as Bluetooth. The developers claim that this means that the sign will illuminate when a call is being made within a vehicle, but not when that phone is connected via a Bluetooth hands free system.

The developers acknowledge that the signs cannot distinguish between a driver using a handheld mobile phone and a passenger within the vehicle using a phone. Despite this, developers hope that knowing that they can be detected will discourage drivers from using handheld mobile phones. The signs will collect data on the number of activations, but there is no system to record the details of vehicles activating the sign.

Drivers caught using a handheld mobile phone can receive a fixed penalty of £200 and 6 penalty points. The new signs come shortly after a study showed that in the first year that this higher penalty came into force, more than 26,000 motorists were caught using a handheld mobile phone whilst driving.

The law still applies whilst drivers are stopped at traffic lights, queuing in traffic, and even when supervising a learner driver.

It's not just making a handheld call whilst driving which can land drivers with a penalty; drivers are also guilty of breaking the law if they touch the phone whilst it is held in a cradle to reprogram a sat-nav or to select music. Keeping a phone in a cradle also provides the potential for distraction when messages and notifications appear on the screen whilst driving.

However, using a mobile phone hands free does not mean that a driver cannot be prosecuted in the event of a collision, particularly one involving serious injury or death. In the event of a serious collision, the police will examine the mobile phone history of a driver. A series of mobile phone calls or lengthy calls may provide evidence that a driver was in a state of distraction, focusing more on the calls than the task of driving.