Detailed Info on the Squirrel Hill Tunnel
KDKA AM's Larry and John were talking about the Squirrel Hill Tunnels and how PennDOT is able to raise the roof of the tunnel- while trying to figure out how, they found a neat website that gives history and construction info on the tunnel and other bridges and tunnels in the Pittsburgh region.
http://pghbridges.com/pittsburghE/0591-4475/squirrelhill_tun.htm