I read an interesting column in Racecar Engineering about the lack of variety in the F1 tracks. (I do not have the article in front of me, but will post a proper reference later) I must say that I agreed with a lot of what was written. It started me thinking about the current state of F1, and the "out of the racing surface" issues encountered last year.
A thought is that there could be an electronic wall built into the runoff areas. If the cars transponder crosses that line, the car is disqualified. Cameras could be used to verify the electronic signals. Consider it a death trap for the car, but non-lethal for the driver. If they can track quali times to thousandths of a second, surely they can do this.