??? So cars heading for the wall can be going that much faster prior to impact? Yes, it might prevent some of the side slaps but think of all the head-on or sharp angle wall impacts, this would NOT be a good idea.
I think what he is saying is move the concrete walls back 3 feet then put in a SAFER type wall system that sticks out 2-3 feet from that....then the track is the exact same width it is now...only safer