Officials selected a tunnel, rather than a bridge, to carry the traffic after experts were convinced that the costs of a twin-tube tunnel could be supported by the toll revenues it would generate. Construction began in January of 1955. At the time, the tunnel was considered an engineering marvel. Tugs then towed the sections to the construction site. The ventilation system includes one ventilating shaft and building over each end of the tunnel.
Fresh air is supplied through a duct under the tunnel roadway and distributed through air flues.
These flues are located just above the roadway on each side of the tunnel. Air in the tunnel tube is drawn off into duct above the tunnel ceiling and then dispersed into the atmosphere. Gigantic fans that supply the fresh air, and remove the stale air, are located in the two ventilation buildings. Carbon monoxide levels in each tube are monitored around the clock. The tunnel was an instant success.