I was driving back from London tonight quite late, when I noticed the car in front slow down.

The speed limit soon changed from 50mph to 60mph, and the police car levelled out at 55mph. The car in front was reluctant to overtake the police car, who was obviously trying to slow traffic on a Saturday night for safety reasons.

I could see no reason to remain behind the police car. Travelling at 60mph, I calmly overtook him. Looking back, there was a line of cars unwilling to overtake the police car, which was still travelling below the speed limit.

I suppose the deterrent does work, but if you're not speeding then why should you be concerned?