[Russell Sobie]

An automated instant penalty system for incidents might not work so well. Conventional wisdom would dictate that when a driver is hit from behind it's almost always the fault of the following driver, but there are times when a car in front is on the brakes at a point on the track you'd expect them to be accelerating, like in a corner exit.  In those times it can be difficult to avoid hitting them.

That's somewhat part of the point I made above. Not everyone on the server has put in hundreds and hundreds (or even dozens and dozens) of hours doing laps in a car on a specific track. It is quite likely that quite a few folks in any given race are seeing the current car/track combo for the FIRST TIME EVER. Being right on someone's tail who fits this description is very likely going to result in you plowing into them at the next semi-challenging corner. I pretty much assume that if someone in front of me does not have lap times in the top five on the server that they don't know a perfect line or a handle on brake points or corner exits, and I'll watch them closely before trying any sort of overtake. 

You can avoid hitting them by assuming they aren't a professional race car driver and then pretending that you are both driving vehicles worth well over your yearly salary.