A policeman has posted a video showing just what NOT to do if you see police ‘blue lights’ in your rear view mirror.

West Yorkshire traffic officer Pc Martin Willis published the video which shows the view from his police car as the driver in front panics and comes to a halt in a live lane of a motorway.

The footage was shot on the M621 near Bradford.

Pc Willis said: “When responding to an emergency this is not what you want to happen!

“If you see blue lights behind you, move over. If the emergency vehicle is going to a job it will pass you. If if wants to stop you, it will follow you onto the hard shoulder. NEVER stop in a live lane!”

It wasn’t the only example of poor driving reported by police this weekend.

In South Yorkshire, police stopped a BMW driver who was travelling at around 160mph on the M18 in freezing conditions on Saturday.