Behind-the-scenes footage has given an insight into an undercover operation on the M4 which saw dozens of drivers pulled over.

Wiltshire Police carried out the operation on the M4 last month using an unmarked lorry, allowing them to get a vantage point they wouldn't usually have.

Drivers were caught eating, texting and even exercising behind the wheel.

Operation Tramline, which is a joint initiative between National Highways and the National Roads Policing Operations and Intelligence, saw 83 drivers stopped for offences on the M4 in just three days.

“Whilst the majority are law-abiding drivers, it is always shocking to see just what some of these drivers think they can get away with – all whilst in control of a vehicle which can be up to 44 tonnes in weight," said PC Luke Hobbs.

As well as the common criminal offences of speeding and using a mobile phone, some drivers were seen watching movies and even exercising in their moving vehicles.

You can watch the full video to catch them in action here.

"We're all too aware that any driver who is distracted has the potential to cause fatal consequences," said Philip Wilkinson, PCC for Swindon and Wiltshire.

"Operations like this allow Wiltshire Police and partner agencies to take these drivers off the road and take action against them to improve their behaviour."