Really the entire Pru/Copley Place complex is a pedestrian skyway over the Pike and rail lines. (Way more than just the Huntington Avenue and Stuart Street bridges). The mall complex provides essential multi-point connectivity between Back Bay and the South End.Where are existing publicly accessible interior pedestrian walkways? The Park-DTX tunnel, the Prudential Station-Prudential Center-Copley Place-Back Bay Station connectors. North Station transit-commuter rail connector...
Most existing walkways have a transit component except for the Pru-Copley Place skybridge.
Seems like skybridges would be pretty exclusively private developments, while any underground tunneling would be involved in transit somehow.
dmdogs, what corridors do you have in mind?