There are numerous ways and designs to place the Sound wall on top of the barrier, or integrate the barrier with the sound wall. Most Sound walls are cast in place or a post and panel. If you already have the required height then the rest of the design is pretty straightforward.
Vallejo Speedway is located on the Solano Co Fairgrounds in Vallejo Calif. I am looking for sound control options. The speedway uses k-rail as a barrier with an 8'fence mounted on it.
The speedway is a 1/6th mile dirt oval featuring 2 stroke engines up to 500cc and 4 stroke engines in the briggs class, and 600cc 4strokes.