New warning signs that can detect if a phone is being used in a car trialled in Norwich

Drivers are used to flashing warning signs - particularly telling them to slow down.

But this is the first sign anywhere that can detect if you're on the phone.

It's gone on up on Martineau Lane in Norwich.

It is of course illegal to hold a phone while driving. But plenty of people still do it.

The new mobile phone sign was designed and manufactured by Dereham based company Westcotec.

They're responsible for more than 100 different types of driver information displays.

The system can't detect yet whether it's the passenger or the driver using the mobile phone or indeed if it's a hands-free device, but they reckon it won't be long before they can.

Meanwhile, no one should be worried if they get a flash from the sign. It won't lead to a prosecution.

It's simply a reminder that driving while on the phone can be a dangerous distraction.

Click below to watch a report from ITV News Anglia's Natalie Gray

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