Hey!  Every time I've been to this section of trail, it's been open to at LEAST foot traffic, if not bike and horse traffic.  I understand that there may be plans to make it lit and fancy like the rest of the bike trail, but for the time being it seems perfectly useable as a mixed-use trail.  (And it seems like it's been waiting for the upgrade for over a decade so maybe they've abandoned the plans and just let the mixed-use trail stand?)  I'll make sure to go back there and check the signage to confirm before changing anything since it's been a couple months, but I'd propose opening up the access tags to at least designated if that sounds ok to you?