Route 94 was commissioned in 1932, from the 1920s State Highway 165. It originally started at Main Street in Glastonbury, which was Routes 2 and 15 at the time. In 1952, the section of the Glastonbury Expressway intersecting Route 94 opened. In 1955, Route 94's western terminus was moved to Sycamore Street, across from the Route 2 eastbound offramp.
In late 1931, state planning maps had Route 94 marked instead as Route 180.
A nip here, a tuck there
Route 94 has had several curves straightened over the years:
- a small curve near Hebron Avenue School and Wickham Road. Planning in 1959; completion date unknown. Part of the old alignment is Hemlock Hill Drive.
- west of Keeney Street to 460 feet west of Route 83: completed in 2004. The new alignment, with two 12-foot lanes and 8-foot shoulders, cuts through mainly forest land. Chaulker Hill Road, which meets the realigned Route 94 across from Keeney Street, is the former alignment. A public hearing was held in 1998, and construction began in April 2002.
- east of Buckingham Church to west of Route 83: planning in 1959 and 1961; completed around 1974. The previous alignment followed Cricket Lane, north of the church instead of south. A dogleg intersection at Route 83 was improved to a standard four-way intersection. The project realigned a stretch of Route 83 as well.
- Old Hebron Road, about a mile east of Route 83, forks northeast into the woods to a dead end at MDC property. I don't know then that segment was retired, but the new road dates back to 1940 or earlier.
- Foote Lane: Route 94 was realigned here around 1958. In 1955, this 0.9-mile road was cited as being one of the most dangerous sections of highway in the state. It was town-maintained until 1955; the state highway technically ended there, and began at the other end. The state agreed to take it over, and at sometime afterward relocated Route 94 to its safer alignment.
Widened to four lanes in the 90s
One primary role of Route 94 is to funnel traffic from a large portion of Glastonbury and Hebron to Route 2. Near the interchange are a few large industrial parks. In the mid-1990s, the stretch between Route 2 and Eastern Boulevard was widened to four lanes to relieve congestion.
Former Route 94 in downtown Glastonbury
In late 2002, a "concept plan" was unveiled in Glastonbury that recommended widening Hebron Avenue to four lanes between Sycamore Street and New London Turnpike. East of Sycamore Street is the beginning of Route 94, and an existing four-lane section extending to Eastern Boulevard.
The town was given a Dec. 10, 2002 deadline to decide how to use a $1 million state grant: widen Hebron Avenue, or reconstructing Main Street (former Route 17) through the historic district.
In January 2003, the town council approved rebuilding part of Main Street and seeking money for widening Hebron Avenue.
As of 2020, widening Hebron Avenue appears to be off the table, two large projects have taken place. The traffic signal at New London Turnpike was replaced with a roundabout; and another roundabout was installed at House Street. Reasons for these included state concerns that traffic signals would lead to traffic backups on the state-maintained Route 94 portion of Hebron Avenue.
For a long time, possibly since Route 2 opened, the guide signs for Route 94 read "Glastonbury Center /  Hebron". However, the better way to Hebron is to stay on Route 2 and use Route 66 from Marlborough. In a signing revision in the late 80s or 90s, the signs were changed to say " / Hebron Avenue".
A 1949 Rand McNally map erroneously shows Route 94 co-signed with Route 85 down to Route 66 (US 6A at the time) in Hebron.