ANOTHER EXPRESSWAY FROM THE SOUND TO MASSACHUSETTS: Compared to other freeway proposals such as I-95 (US 1), I-91 (US 5) and I-84 (US 6), the CT 10 Expressway proposal was a relatively new one. The first mention of the CT 10 Expressway proposal came in 1962 from the Tri-State Transportation Commission. The proposal called for a four-to-eight-lane, 53-mile-long expressway from I-95 in West Haven north to the Massachusetts border. Between Southington and Plainville, the CT 10 Expressway designation was to be co-signed with I-84 (Yankee Expressway).
Improvements to CT 10 came in the 1940's in the form of widening and construction of grade separations at CT 322 (then US 6A) in Milldale and US 6 in Farmington. No further improvements were planned by the state through the 1950's: the CT 10 Expressway was not included in the state's Thruway Plan of 1953.
The 1960's and early 1970's proposals for the CT 10 Expressway envisioned a six-to-eight lane expressway beginning at I-95 (Connecticut Turnpike) near EXIT 43 (CT 122 / First Avenue) in West Haven. An alternative proposal had the CT 10 Expressway beginning at EXIT 6 on I-91 in New Haven; from here, the CT 10 Expressway would travel north along the shores of Lake Whitney. Continuing north along the vicinity of the West River, the CT 10 Expressway was to continue north past CT 15 (Wilbur Cross Parkway), intersecting a proposed CT 40 Expressway extension near Mount Carmel.
In its 1966 report, Transportation 1985: A Regional Plan, the Tri-State Transportation advocated construction of the CT 10 Expressway as follows:
This north-south expressway will serve the fast growing suburbs north of New Haven. It will provide a route to the western past of the Hartford metropolitan area.
Together, the CT 10 and CT 40 expressways were to form a 12-mile northern loop around New Haven. In 1968, the state of Connecticut applied for Interstate funding for this loop, but was denied by the Federal government.
North of the CT 40 Expressway, the CT 10 Expressway, which was to narrow to four lanes from Mount Carmel north to I-84, was to parallel the existing CT 10 west of the existing route. Diamond interchanges were to be built at CT 42 (North Brooksvale Road) and CT 68-CT 70 (West Main Street) in Cheshire. A more complex interchange was designed for the intersection of the CT 10 Expressway, I-84 and I-691 (then known alternatively as the US 6A / CT 66 Expressway) in Milldale. Expressway connections between I-84 and the future CT 10 Expressway were constructed at the current EXIT 29 on I-84.
For approximately 3.5 miles, the CT 10 designation was to be multiplexed with I-84 between EXIT 29 in Southington and a point between EXIT 31 (CT 229-West Street) and EXIT 32 (existing CT 10-Queen Street) in Plainville.
North (and west) of I-84, the CT 10 designation was to be multiplexed with the CT 72 Expressway to a multi-level interchange just west of the existing CT 10 (Farmington Avenue). Leaving the CT 10-CT 72 "stack" interchange, the CT 10 Expressway (returning to four lanes) was planned to run along the Quinnipiac River valley, and later along an abandoned Penn Central railroad right-of-way through Farmington and Avon. Additional multi-level interchanges were to be built at the (eventually unbuilt) CT 4 and US 44 expressways, and a diamond interchange was to be constructed at US 6 (New Britain Avenue).