Tuesday Night in Black & White  

I was reading at a discussion in the 70's section where several Vault contributors were talking about being scared to walk on the little road that ran next to the wall between the 3rd and 4th turns while the cars were on the track when they were kids (yeah, me too!).  How about those dudes near the "fence" in picture 1?  I am not sure if the fence is there for car containment or just to mark the ourside of the track.  Or maybe so the horses didn't continue straight during the fair races.