I was having the same issue until I stumbled accross a post in the Steam forums. It said that the problem can be mitigated by adding a file cache folder for the game. Programs typically add this folder when they install, but for some reason, ID did not do this. You can add this folder by doing the following:
The typical path for this file's location is c\users\(your user name)\AppData\Local
(now this is where it SHOULD be, but is NOT....)
In the \local folder create one called id software, then in that folder create on called rage (all lower case. When you start up the game it will create two files in that folder: filecache000.bin, and filecacheheader.bin.
Since I did this, the game has not crashed. I hope this helps!
No problem, I hope it works for you. The only thing I did not care for in the game was the racing. Other than that, I love the game.