I highly doubt any new freeway tunnels will be constructed under Manhattan, let alone anywhere in New York City. Replacing the Gownaus Expressway with a Gowanus tunnel was killed in 2011, and bypassing the existing Brooklyn-Queens Expressway with a tunnel (the segment between the NY 27 Prospect Expressway and the Flushing Ave. interchange) would have been nice, given how difficult it will be to reconstruct the double-decked portion underneath the Brooklyn Heights Promenade. I could dream up a million other things, such as building a tunnel to connect the end of the New Jersey Turnpike-Newark Extension with the Holland Tunnel, bypassing the signaled intersections on 12th and 14th Sts. in Jersey City.