This is a true story, 100%.
A guy I used to work with in Belgium was driving on the faster lane of the motorway. A car came very close from behind -- you know, as if wanting him to mske way. Instead of letting them pass, he accelerated. The other car also accelerated. Then he thought the other car wanted to race him, so he kept driving faster and let the other car try to catch up with him. This went on for a while, and he was having fun -- until suddenly the other car revealed that they were the police. Since by then he had been driving waaaaaay over the 120Km/h speed limit, he got a huge fine.
So, what was going on there? Anyone relate? Any suggestion as to the functions involved?