Though it offered the forum for the presentation, the MWCDC is not taking a stance on the proposal — at least not yet. “The MWCDC does not take positions on any developments that are proposed by organizations other than us,” said MWCDC Executive Director Gordon Davidson.

The organization could offer a developer letters of support, opposition or neutrality “based on the input we receive from the community,” Davidson says.

Goldman says he has had meetings about the proposal with the U.S. Army Corps of Engineers and PennDOT, among others. Those organizations did not reply this week to NEXTpittsburgh’s requests for comment. Port Authority of Allegheny County was not aware of the project, a spokesperson said.

Goldman is doubling down on the safety of his proposal. He says the firm ZipRider, whose zipline in Alaska lays claim to being the longest in the world, says the tentative proposal for Pittsburgh would work “from a design standpoint.”

Pittsburgh Zipline Company’s proposed procedures also come from the BridgeClimb in Sydney, Australia.

“People have been climbing to the top of the bridge since BridgeClimb’s inception in the late 1990s,” Goldman says. “It has been open every day, weather permitting, since then — and nothing has ever fallen onto the roadway, railway, busway or waterway below. This is how we know that our zipline will be inherently safe for both our riders and those below.”