Devon and Cornwall Police are launching a crackdown on the use of mobile phones while driving.
Offenders face a £1,000 fine under government plans
The campaign coincides with government plans to make it an offence for a driver to use a mobile phone that is not hands-free.
According to the Royal Society for the Prevention of Accidents, more than one in four people admit to answering or making a call or text messaging while driving.
From next week, police will be stopping vehicles whose drivers are seen using mobile phones.
Officers will explain to motorists the risks they are facing and will be distributing leaflets.
Police Constable Nigel Bishop said: "Mobile phone use in cars is a danger for everyone on the road.
The best idea is to turn your phone off while driving - if you have to use the phone, stop in a safe place
David Morrish, Devon county councillor
"We will be stopping drivers to warn them how dangerous it is."
Under the government plans, offenders could face fines of up to £1,000.
The campaign is being backed by local authorities, including Devon County Council, and is planned to compliment the Department for Transport's "Think Road Safety" month.
David Morrish of Devon County Council said: "Driving while being distracted by a phone will impair a driver's concentration and that will increase the chances of an accident.
"Even the most careful of drivers will be distracted by a phone call or text message.
"The best idea is to turn your phone off while driving. If you have to use the phone, stop in a safe place."