I was driving northbound on the M5 motorway the other day (that's "freeway" to any Americans out there, and "autobahn" to any Germans), when something happened to me which has never happened to me before...

A police car came up in the center lane, it's lights flashing but no siren. Once the car had got in front a large bunch of cars, they started waving their arms up and down out of the side windows, which means slow down. We all slowed down, all 3 lanes, to about 30mph, with the police car a short distance ahead of us, the lights still flashing. My heart raced, I thought we were about to pass some mangled car wreckage or something.

Then after a few minutes, the police car's lights stopped flashing, and they waved us forwards, and we all went back up to full speed again. "Hmmm" I thought to myself, "what was all that about?"

Then, a few minutes later, just before the junction I was about to turn off, I looked over at the hard shoulder and this is what I saw: There was an unmarked black police car with its hidden blue lights flashing and a neon sign saying "Police Slow". In front of that was a black car with a bunch of goths getting out of it, with the other police car parked in front of it and the policeman leaning over and talking to the driver.

There must have been a high speed car chase going on between the two black cars (the goths and the unmarked police car) and they didn't want us lot to all get caught up in it in case it went horribly wrong.

Hopefully they had a camera on board and it will appear in one of those exciting police documentaries that they keep showing on BBC1. Far more exciting than staged car chases in films, because you know it's real.