Check with Alex Tarr, it was fine when it was mapped and went to the excrement after a major fire.
It got a lot thicker a year later and impossible the following year as the effects of the fire changed the scrub. I tried to convince a few people we should go back and went out there for a "run" but seriously it was horrid and knew I would get much excrement thrown my way if I left it on the OWA calendar!
Maybe it is time to check out if the scrub has died back?