1) Get Port Authority to change the rule. It’s a paperwork exercise. No studies or infrastructure or anything else needed.
2) Access from the east: From West Liberty Ave, use Hargrove St to the junkyard, go behind their building up onto the RR right-of-way just at the point of the used and unused tracks splitting. Use the unused R-O-W at least as far as Wabash. This will require easements of various sorts, I’m sure, and these won’t be easy to obtain, I am also sure, but physically it should not be too difficult. Lawyers, not gravel, will be the greater cost here.
3) Access from the west will be much harder, as there is a lot of distance involved, plus old infrastructure like RR grades and bridges are either missing or in such disrepair that they may as well be missing. I suspect that major work such as what was done along the trail between the 31st and 40th Street Bridges will be needed to stabilize the old RR bed for trail use down to the West End. We’re talking about several million dollars, I’m sure.
4) To access trails up into that part of Beechview adjacent to and above Brashear HS, I don’t know what all would be involved.