I found out, though I'm sure someone else discovered it already - there's probably even a thread on it somewhere - that a player has a great deal of control over overtaking meets. And after the AI extra is overtaken, the player can "drop fusees" off to stop the extra, or if the player is stopped, "call out a flagman". This is accomplished by setting trailing point switches against the AI extra, and then releasing him before you lose control over the switch by passing another one. He'll follow you like a dog.
It is super handy for setting out cars and what not without being steam-rolled by the AI. Just be careful though that in switching you don't trip the switch that is holding him back!
Give it a whirl!
