Please say it ain't so! Not another obnoxious zipline infesting an American zoo! When will the madness end? (Thankfully this menace seems to not be spreading to zoos beyond our borders).
Bronx's seems to be being built almost completely in an area that's undeveloped and I don't think will be visible from the main zoo grounds (it seems to be tucked in a wooded area on the perimeter well away from any animal exhibits and more near the overflow parking) which is good, but they also seem to be putting platforms up in some former hoofstock enclosures...
I remember my one visit to Bronx Zoo. I took the subway and had to walk about two blocks to the pedestrian zoo entrance (which I think is on the opposite side of the zoo as the "safer" car park entrance). It was a rough neighborhood with drug dealers in a souped out sedan cruising the lower class neighborhood. If the zoo wants to make a zip line that is truly exciting, they should make it go over this neighborhood and offer night rides. The thrill will not just be zipping along, but zipping along and trying not to get shot!
I've gone to the zoo via the same route before (assuming you mean the Fordham station right next to Fordham University, though that's more than two blocks away). I don't recall the neighborhood being quite that rough but I tend to take the bus from the station and back just in case