“The photographs show the back of my car and the white lines at the side of the road. The second photograph shows that it was taken 0.5 seconds later by which time I had moved five white lines along.”

He remembered from school you could calculate speed if you had the correct distance and time. He said he looked on the internet and found an official website stating that lines on the motorway are spaced two metres apart.

“That meant I had driven 10 meters in 0.5 seconds or 20 meters per second. That works out at precisely 44.8mph.”