Adger,
Though you got a pretty good shock hitting a metal guard rail, what you experienced was similar to the effects of the SAFER barrier because steel guard rails give and deform, while concrete forms a rigid barrier. The biggest drawback to steel guard rails - and the reason they are banned at most facilities - is that they not only deformed, they also came apart and the exposed ends turned into lethal weapons.
The SAFER barrier's square metal tubes also deform, but do not turn into knives and spears in the process. However, they are not effective for crashes where the car's momentum is parallel to the wall or nearly so and they tend to either grab the car or have a rebound effect in shallow-impact geometries. On an oval track, in a corner, centrifugal force sends the car into the wall at a greater impact angle and that's what the SAFER walls are designed for.
Bullrings like Bristol have them all the way around the track because the cars are turning almost all the way around the track, but they are not used on the outside walls of the straightaways on larger tracks. They are used on the inner walls of the straightaways where those walls are far enough from the racing surface that the likely impact angle is high enough for the walls to work (for example, on the inside wall in turn four at Daytona).
On dragstrips, most wall impacts are parallel or nearly so, and the SAFER technology not only won't help, it might make those impacts more serious. In other words, the obvious solution isn't necessarily the correct solution and it's going to take a lot of testing and analysis to come up with something better than the rigid walls that are currently the norm at dragstrips. Perhaps the crushable structure needs to be on the race car, not the wall, for example?
- Larry
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