Route Numbering

In the 1920s, Route 66 was part of the old State Highway 111; in 1932, this became part of Route 14, a highway extending nearly 90 miles from Woodbury via Waterbury, Middletown and Willimantic into Rhode Island.

On Jan. 1, 1941, Route 14 between Woodbury and Willimantic was renamed US 6A, to encourage its use as an alternate cross-state route. This was one of several US 6A's that existed up to the 1960s.

In 1965, the Highway Department announced plans to decommission US 6A, for "the convenience of the motoring public and to connect Route 2 to I-84." The portion from US 6 in Woodbury to I-84 in Waterbury would become Route 64. The portion from I-84 in Southington to US 6 in Columbia would become Route 66. These changes took place on July 26, 1967.

Much of today's Interstate 691 opened to traffic as part of Route 66. A segment leading easterly from US 5, across I-91, and ending in Middlefield, opened in 1966. (The portion east of I-91 remains part of Route 66.) A segment from old Route 66 (today's Route 322) to US 5 opened on Aug. 30, 1971. Officially, the state applied the I-691 number to the freeway (both completed and uncompleted parts) from I-84 to I-91 in 1976; but I-691 was not signposted until the freeway was completed in 1987.

In 1983, the state abandoned the idea of I-84 to Providence, and on Dec. 12, 1984 made several numbering changes to the area. Among these, US 6 was shifted to the former I-84 freeway north of Willimantic, and Route 66 inherited the 6-mile part of US 6 through downtown. At this time, Route 66 reached its greatest length, 46.66 miles, extending from I-84 in Southington to US 6 east of Willimantic.

On Dec. 1, 1987, I-691 was completed to I-84 and took over the 66 freeway west of I-91. The 2-lane portion of 66 in Southington was given to Route 322, which now ends where the old 66 freeway began. (Historically, this was exit 4, but in 2023 was renumbered to exit 5.)

The Arrigoni Bridge

The four-lane Arrigoni Bridge, crossing the Connecticut River at Middletown, opened in 1938. At the time, it was the longest bridge (3,420 feet) in New England.

Freeway plans

In 1963, the state added a 40-mile US 6A freeway to its long-range plans. The highway would follow today's I-691 and Route 66 from Southington to Willimantic. Only the portion from Southington to just east of I-91 was built, most of it now I-691.

In the late 1960s, the state studied the Route 66 corridor between Middletown and Route 2, where the new freeway would intersect in either Marlborough or Colchester. The recommended new Route 66 would pass south of downtown Middletown, across a new Connecticut River bridge (see Arrigoni Bridge for more info) into Portland, and then south of downtown East Hampton.

The 1975 Master Transportation Plan called for extending the existing Route 66 freeway eastward, through Middlefield and Middletown, to touch down across the Connecticut River in Portland. Estimated cost of the 8.7-mile link, including a new river bridge, was $125 million. The state also recommended using "trade-in" funds from withdrawing portions of I-86 and I-291 to fund building the remaining 3.6 miles of the Route 66 freeway in Southington and Cheshire.

The state might have reserved an exit number on Route 2 in Marlborough for a Route 66 freeway interchange, which would explain why there is no exit 14. I have no proof though. (As the state moves to revise its exit numbers to mileage-based on all freeways, such hints of "missing" exit numbers will disappear.)

In 1993, the Route 66 freeway from Middlefield to Middletown was cancelled, for reasons including environmental impact to the Higby Reservoir. Signs on I-91 northbound at Meriden advise Middletown-bound drivers to use Route 9 instead of Route 66.

In 2000, the Connecticut Road Builders Association recommended dusting off the proposal, creating a freeway from Meriden to Route 2 in Marlborough. The group cited increased traffic and tourism in southeastern Connecticut as a driver for better transportation facilities.

Meriden to Middletown: widened to 4 lanes

The Route 66 freeway between I-91 and Route 9 was dropped from state plans in 1993 because of environmental concerns. In its place, a four-lane undivided treatment was proposed. After much design and negotiation, construction started in late 2003, and finished around 2007.

The $21.6 million project widened Route 66 to 4 lanes from the freeway terminus in Middlefield to the Washington Plaza shopping center in Middletown. (East of that point, Route 66 was already four lanes wide leading to Main Street.) The project not only added capacity, but also eliminated dangerous curves near the reservoir.

The widening proposal was not without controversy. Residents opposed to it cited the dangers to the reservoir, and the damage to Middlefield's character; the state responded that it was building in a closed loop pollutant containment system, and that the undivided four-lane road was an alternative to the freeway originally planned.

In June 2000, the state EPA commissioner overturned initial approval of the plan, in response to opposition from local residents. The commissioner said ConnDOT failed to provide that widening to four lanes would improve safety, and gave the state 60 days to back up its claims.

In January 2002, the state Department of Environmental Protection approved the project, after changes were made to address environmental concerns, including an "innovative" storm drainage system and some alignment changes to the road.

In March 2002, the state announced that construction would be scheduled for late spring or early summer; but fiscal issues ended up delaying it. Construction began in late 2003.

The work was split into two projects: one leading from the freeway end to Jackson Hill Road in Middlefield (began late 2003), and the other leading from there to Washington Plaza (started in 2005).

Other improvements

The four-lane divided section of routes 66 and 17 in Portland dates back to the early 1940s. In 1997, safety and capacity improvements were done, including removing some U-turns, adding median railings, and adding left-turn pockets.

At some time before 1960, an older alignment of Route 66 in Hebron followed Wellswood road and Mill Stream Road.