The North Portal of the Liberty Tunnels in 1924, shortly before opening. Note how the lanes veer off towards Arlington Boulevard. McCardle Roadway, descending from Mount Washington, had not yet been completed and northbound traffic was routed to the right.

The northern end of the tubes in 1925. Bridge work was beginning and soon McArdle Roadway construction would start. Once the intersection was completed, in 1928, a traffic circle was installed and vehicles flowed to the left and to the right.

The North Portal in 1928. Only four years after opening, the white facade of the tunnel entrance already showed the effects of the sooty atmosphere of the Smokey City. At the time the traffic circle outside the tunnel worked.

As the number of vehicles on the roadway increased, the traffic circle became a hindrance.

By 1940 the traffic circle was removed and replaced by Traffic Division officers. The traffic patterns changed slightly. Coming out of the tunnels there were no more right hand turns onto McCardle Roadway. Approaching the tunnels, left turns to McCardle were also eliminated. Traffic flow may have improved for the better, but the smog from the steel mills is so thick that it partially obscures the view.