Baltimore Harbor Tunnel

This week I drove from Richmond, VA via Washington DC to Philly. To save time driving to I took the Baltimore Harbor Tunnel into NJ.
In November of 1957 the Harbor Tunnel Thruway was completed providing the first major bypass of Baltimore. The centerpiece of this expressway was the Harbor Tunnel, the longest twin tube trench type tunnel in the world at the time of its construction. Excavation of the trench began in 1955. The tunnel sections were manufactured on land at steel plants in Maryland and New Jersey, launched like ships, and floated into place. After being sunk, the sections were locked together by divers working in complete darkness. One of the chief designers of the tunnels, Ole Singstaud, had also worked on the Holland and Lincoln Tunnels in New York. The finished expressway stretches from Howard County to the eastern edge of Baltimore City. With its opening the north-south travel time past Baltimore was cut by 70%. Motorists could bypass the Baltimore bottleneck and the approximately 50 traffic lights that came with it. Today it is designated I-895.