Bigpower

http://www.liveleak.com/view?i=a83_1355789956

I'm amazed at the 4.47 run with the front wheels off the ground for most of it.

Aside from cost is there any reason why drag strips wouldn't upgrade the strip walls by adding something which collapses on contact/absorbs most of the impacting force as opposed to 2 foot thick concrete walls?

I would guess the reason for concrete walls is to contain everything within a controlled area and its easier to maintain if you had to repair deformable walls everytime someone ran into them you wouldn't get much racing done...
Also when you think the types of fuel and the speeds associated with drag racing a good solid wall is going to do a far better job and keeping the cars etc out of the crowds...

Containment makes sense from a spectator safety perspective, I meant perhaps adding something to the current walls to absorb some of the impact when cars/drivers spank in....although I suppose space may also pose a problem with doing that as the strip is pretty narrow as it is

Oops
http://youtu.be/SeNnHv3geNU
Look how high the wheel flies up!