[6] Studies were conducted for a tunnel through West Rock on the Wilbur Cross Parkway in the late 1930s.

A common problem engineers faced was to project a line as near to New Haven as possible and avoid the rock formations in the area.

Consultants decided that a tunnel through West Rock would cost $100,000 less than a route around the mountain.

[6] After the tunnel was decided as the best option, workers began to test the character of the rock.

A 30-inch metal ventilating line was installed in each bore suspended at the height of 7 feet above the tunnel floor.

Removal of any fire extinguisher would automatically change the lights and start the ventilating fan.

[6] From January to February 2024, the tunnel lights were changed from Low-pressure sodium (LPS) lamps to LEDs.

[7] Public reception was mixed, due to a fondness of the warm and intense atmosphere provided by the LPS lamps.