The UK’s first road signs which will electronically detect and warn drivers who are using mobile phones have been introduced. These signs can detect when signals are being transmitted by a mobile telephone inside a car, and then flashes a symbol of a mobile phone with a line through it to remind drivers not to use their handsets while behind the wheel. 
 
 The road signs work by using a scanner to detect the radio signals emitted when someone in the car is connected to a call, with this data used to illuminate a sign further down the road. 
 
 The scanner can pick up both mobile phone radio signals and Bluetooth signals, and differentiates between the two. This means those using Bluetooth for a hands-free connection, will not be warned by the sign, as if the scanner picks up a Bluetooth signal, it will disable the light. 
 
 However, they do not monitor data connections, meaning those using internet services on their phones will not be detected. 
 
 The first of three £6,000 electronic signs was yesterday introduced in Norwich, Norfolk. ||||| Image copyright Norfolk County Council Image caption Phones that are being used via a vehicle's Bluetooth system or hands-free will not trigger the warning system 
 
 A roadside system that detects if a mobile phone is in use in a passing vehicle is being piloted in a UK first. 
 
 Despite being unable to pick up whether the driver is using the phone, it is hoped it will act as a deterrent to people making calls behind the wheel. 
 
 The technology picks up the phone signal in the vehicle and activates a roadside warning sign of a mobile with a red line through it. 
 
 Being initially tested in Norfolk, the system cannot record footage. 
 
 However, it is designed to pick up whether the phone is being used hands-free or via a vehicle's Bluetooth system and as a result will not trigger the sign. 
 
 Phones: What you can't do behind the wheel 
 
 Chris Spinks, of Westcotec the firm behind it and former head of roads policing in Norfolk, said: "So many people, by force of habit, can't resist using their phone. 
 
 "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." 
 
 The signs are in place in four locations in Norfolk before being moved on to new sites within the county in a month's time. 
 
 How does the system work? 
 
 Image copyright Norfolk County Council 
 
 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. 
 
 Source: Westcotec 
 
 Peter Williams, RAC road safety spokesperson, said: "While this new signage is no replacement for a uniformed police officer catching someone in the act, it could be enough to make some drivers think twice - and that has to be a positive step forward. 
 
 "So ironically, just as technology has enabled the problem of drivers using mobile phones illegally, it can also be a big part of the solution in getting people to stop." 
 
 Statistics from the devices will be shared with Norfolk Police, the county council said. 
 
 The council said that enabling the system to record specific number plates could be a "future development" with it. 
 
 Insp Jonathan Chapman, of Norfolk Roads Policing unit, said: "Any scheme which prevents this kind of behaviour is welcomed. 
 
 "Using a mobile phone at the wheel is one of the fatal four road offences which can have devastating consequences if it causes a fatal or serious collision." 
 
 'Lagging behind' 
 
 Kate Goldsmith, whose daughter Aimee was one of four people killed when a lorry driver smashed into stationary traffic while he was scrolling through music on his smartphone, said she "welcomed" the technology, but said police need video evidence to get convictions. 
 
 Image copyright Family Handout Image caption Tracy Houghton, her son Ethan, stepdaughter Aimee Goldsmith and younger son Josh were all killed in a crash on the A34 in 2016 
 
 She said: "Law enforcement technology has been lagging behind for a decade and not made any easier by motor manufacturers that encourage users to plug in their devices before each journey. 
 
 "The tragedy of Aimee's death and trauma to my son who followed in the car behind has made the use of devices in vehicles less of a debate for me. 
 
 "When you're driving, do just that and nothing else."
– Using your phone while driving in the UK? Expect a warning from a smart road sign, at least if you're in Norfolk. The county is introducing road signs that use scanners to electronically detect the radio signals transmitted when mobile phones are connected to a call—and then flash a symbol (on a sign further down the road) showing a cellphone with a line through it to the offending driver to remind him or her such behavior is a no-no. The scanners differentiate between radio signals from cellphones and Bluetooth signals, so drivers using a hands-free Bluetooth connection to talk on their phones won't get a warning, the Telegraph reports. But some phone users may get through, as the scanners won't pick up data connections from drivers using internet service on their phones. Though the signs won't record any footage, meaning no fines will be issued based on the data they collect, the data will be shared with police to arrange possible crackdowns in the future in the areas where cellphone use is most prevalent. And a road safety spokesperson tells the BBC the signs may be enough to at least make drivers "think twice" before using their phone while driving. New Zealand, Argentina, and Slovenia are considering similar technology. (Time for police to have "textalyzer" powers?)