In December 1944, Connecticut proposed three interstate routes, which are roughly where I-84, I-91, and I-95 are now. A more specific route for I-84 was announced in December 1955. Some highways predating 1956 were incorporated into I-84 (see "Before the Interstate Era"). On August 14, 1957, the American Association of State Highway Officials (AASHO) approved the general routes for interstates 84, 91, and 95. On June 27, 1958, it approved the numbers.
The first sections of new I-84 roadway to open were in the west, near Waterbury and Danbury; a 15-mile section near Danbury opened Dec. 16, 1961. The last section of I-84 to open was the Plainville-Farmington section, on Dec. 14, 1969.
Known opening dates:
- New York State Line to Sandy Hook section of Newtown (15 miles): Dec. 16, 1961.
- Housatonic River, Southbury, to Waterbury town line (11.3 miles): Dec. 17, 1963.
- Scott Road, Waterbury to Marion Road, Southington (4.1 miles): Dec. 18, 1961.
- Marion Road, Southington to Queen Street (Route 10), Southington (6 miles): Dec, 19, 1961.
- Plainville to Farmington (3 miles): Dec. 14, 1969.
- Corbins Corner (exit 40) to Prospect Street (exit 44), West Hartford: Sept. 3, 1965.
Before the Interstate Era
Traffic on US 6 and US 6A was already significant before interstate highways started opening in the late 1950s. In 1955, a new four-lane section of US 6/202 in Newtown opened, bypassing the old Church Hill Road and Glen Road routing. It's now part of I-84, which was reconstructed in the late 1960s and again in the 1970s.
In Waterbury, a section of expressway from South Elm Street toward Harpers Ferry Road opened in the late 1950s, and was open to Route 70 by 1960. The earliest part of this expressway was built in 1948.
In Hartford, planners were mapping routes for the proposed "East-West Expressway" in the 1940s; this plan became the "relocated US Route 6." Similar plans were being drawn in the Waterbury area and New Britain; much of I-84's serpentine route between Waterbury and Hartford arises from these plans.
The stone arched Bulkeley Bridge (named after former Hartford Mayor Morgan B. Bulkeley), was built in 1908, and originally charged a toll; it now carries I-84 across the Connecticut River. East of there, I-84 uses the Wilbur Cross Highway right-of-way from East Hartford to Union. The original highway, built as a narrow four and six-lane road from 1948-1954, was completely reconstructed in the 1970s and 1980s. I-84 is now 10 to 12 lanes in East Hartford, eight lanes (including HOV) to Vernon, and six lanes to the Massachusetts Turnpike in Sturbridge.
In 1958, Connecticut Gov. Abraham Ribicoff called building I-84 the "top priority", and work in the Danbury area began in October of that year. On Dec. 16, 1961, 15 miles of four-lane expressway were opened, from the state line to Sandy Hook. The work included the 3-way interchanges for the proposed US 7 expressway at exits 3 and 7. Opening ceremonies were held at the Lake Avenue overpass in Danbury and the US 6 overpass (exit 10) in Sandy Hook.
Beyond Sandy Hook, the highway narrowed to the undivided four-lane US 6 and 202 bypass built in the 1950s. Around 1967, this was upgraded to a divided highway, but was still substandard between exits 10 and 13, including a narrow Rochambeau Bridge over the Housatonic River, and two small interchanges (exits 11 and 12) west of the riverbank. Both the narrow profile of the highway and the short ramps of the interchanges posed safety problems.
In the early 1970s, the state conducted public hearings to improve the area. A new westbound span of the Rochambeau Bridge would be constructed, allowing six lanes of traffic over the river. Exits 11 and 12 would be eliminated, and exit 13 made safer (but now a partial interchange, only serving traffic to and from the west). Around 1976, all this was done, and a new 3-level interchange (which became exit 11) for the proposed Route 25 expressway was built. (The interchange, at the modern exit 11, currently serves two-lane Route 34 instead.) Exit 12, which served Riverside Road immediately west of the Housatonic, was deleted and not replaced.
The overlap of US 7 and I-84, from exits 3 thru 7 in Danbury, became one of the worst bottlenecks in the state in the 1980s. (US 6 and US 202 also shared the same four lanes of freeway.) Early in the decade the Housatonic Valley Council of Elected Officials (HVCEO) presented a traffic projection to DOT justifying widening the overlap to six lanes. That widening was completed in 1988.
The only double-decked section of I-84 crosses Route 8 in Waterbury, and that interchange is the focus of a multi-billion-dollar plan to reconstruct it. East of downtown Waterbury was an old, twisting, narrow four-lane freeway that was replaced in segments, starting in the early 1970s and ending in the late 2010s.
Where I-84 eastbound curves to the south, approaching Route 69, the original alignment had the eastbound lanes cross over to the left side for a short time, with some access ramps to and from Union Street. This was the only such crossover in the state, and was replaced around 1973 with a straighter, wider section: 6 lanes with C/D lanes eastbound.
Hamilton Avenue to Austin Street was the next bottleneck: a 2.7-mile stretch of 50-year-old, curving, four-lane freeway. Starting in March 2015 and ending in August 2019, the state added a lane in each direction, straightened out a curve, and relocated ramps to combine two closely-spaced interchanges. Exit 24 for Harpers Ferry Road no longer exists.
Austin Street to SR 597 in Southington was another 3.5-mile stretch of four-lane freeway, widened to six lanes in 2006. However, this project was marred by the discovery of improperly installed storm drains, catch basins, and light fixtures, as well as flaws in how they were inspected. About $22 million in additional work and repaving was required; the state sued and recovered this amount from the contractors.
Exit 26 (Route 70) was modified on the westbound side to remove the weaving caused by opposing loop ramps; it's now an asymmetric diamond interchange.
Save Exit 29!
The Southington widening project originally called for the elimination of Exit 29, a left-hand exit from I-84 westbound to Route 10 in Southington. Eliminating the ramp bridge over the eastbound lanes would have simplified the widening operation. A groundswell of local support under the "Save Exit 29" caused the DOT to change its stance in late 1998, and now "Connecticut's most-loved exit" stayed open.
Exit 29, known to the state as SR 597, was to be the north end of a Route 10 freeway to New Haven.
New Britain - Plainville
The Metacomet Ridge, a north-south line of traprock crossing the state, separates New Britain and Plainville. Both the I-84 and Route 72 expressways share the same gap in the rock (as does Route 372 and a quarry); exits 33, 34, and 35 suffer from congestion, left exits, and weaving patterns.
In December 2001, changes were made to the Crooked Street interchange area to address the problem. The entrance and exit ramps between Crooked Street and I-84/Route 72 westbound (Exit 34) were removed. In their place, a four-lane exit ramp and one-lane entrance ramp were provided for Route 372 to and from Route 72 westbound (exit 2), east of the 84/72 interchange.
The canyon through downtown Hartford used to be a nightmare: three exits and two entrances in 0.2 miles. There was also no direct connection from 84 east to I-91 north, or I-91 north to I-84 west. The misdesign may have had a long heritage: a September 1948 Bureau of Highway Planning document is titled "An appraisal of two proposals for the treatment of the Riverfront Boulevard - North Meadows Highway [now I-91] intersection with the East-West Expressway [now I-84] in the city of Hartford." The question on many drivers' lips would be "what about the one they didn't pick?"
Contracts were awarded in September 1957 for the interchange work. Construction was well along by 1961.
A Hartford radio station once ran a fake promo ad for a demolition derby on the "Morgan Street Offramp" -- the congested city street drivers from eastbound I-84 to northbound I-91 were forced to crawl along. The nearby Whitehead Highway (to be I-484) was intended to carry 84-91 traffic, but was never completed. At least once this intersection gained notoriety in a car magazine as the worst place to drive in the U.S.
Starting in 1987, several ramps were moved or deleted, and on October 11, 1990, a direct flyover ramp, rising 80 feet above Morgan Street, opened to provide freeway-to-freeway access.
The interchange enhancement, part of 11 years of roadwork in the area, also involved relocating the southbound lanes of I-91 two levels down and rebuilding the Founders Bridge.
Slouching Toward Providence
I-84's intended east end has been changed twice, from the Mass Pike (I-90, Sturbridge) to Providence and back. In late 1968, the FHWA approved a new Interstate connection from Hartford to Providence. For a short time the proposed highway was called I-82, but in 1969 became part of a rerouted I-84. The existing section of I-84 from Manchester to I-90 was redesignated I-86 (see map).
In 1970 and 1971, Connecticut built two isolated sections of the eastern I-84, in Manchester and Willimantic. Both were signed I-84. However, in 1982 Rhode Island canceled its portion of the highway, citing concerns over the Scituate reservoir, Providence's main fresh water supply. In August 1983, Connecticut canceled its portion, and the I-84 to I-86 numbering was rolled back. The section of I-84 in Manchester became I-384, and the Willimantic section became part of US 6. This was made official on Dec. 12, 1984.
Around the year 2000, the state was advocating an 11-mile freeway built between those two sections, from Bolton to Willimantic. This would take traffic from the winding, 2-lane "Suicide 6" (US 6) connecting the towns. However, that effort is moribund.
For more on the history of I-84 eastward, see Hartford to Providence.
In the Northeast
The portion of I-84 between East Hartford and the Massachusetts state line is part of the Wilbur Cross Highway, which opened in the 1940s as a two-lane highway, and as a four-lane divided highway from 1948 through 1954. This highway was added to the state's interstate system as part of I-84 in 1958.
In the early 1960s, the state was already planning to widen this section. In 1964, federal approval was obtained to widen I-84 to ten lanes reaching Route 83 in Vernon, eight lanes to Tunnel Road, and six lanes through the Massachusetts state line.
Work on this widening began in the mid-1970s, from Union westward; new lanes were completely opened starting in 1976. Work finished around 1990 with the completion of the I-84/I-384 connector. Provisions were made in Manchester for the reconstruction for I-291, which was completed in 1994.
High-Occupancy Vehicle (HOV) lanes
The state's first HOV lanes opened on I-84 in the fall of 1989. Also known as carpool lanes, diamond lanes, or restricted lanes, they allow buses, vans, and cars with two or more passengers to bypass stalled traffic on the general purpose lanes. One HOV lane in each direction runs along I-84 between Route 2 and Vernon.
Many areas implement HOV lanes differently. On I-84, the HOV lane is to the left of the general-purpose lanes, separated by about 8 feet of asphalt painted with warning stripes. Crossing into or out of the lane is prohibited; instead, separate HOV exit and entrance ramps are provided. Westbound HOV entrances are at I-84 east of Route 83; Routes 30 and 83 (exit 64); Buckland Street, and I-384; traffic can exit at Silver Lane or merge with I-84 proper near exit 55. Eastbound traffic enters the HOV lane ahead of exit 58, or from Silver Lane; exit ramps are in the same locations as the westbound entrance ramps.
The lanes are marked with a black rectangle enclosing a white diamond. Signs over the lane, and on entrances to it, are black text on white background. Entrances to the lane call it the "Restricted Lane." Lane restrictions are in effect 24 hours a day. When the lanes opened, cars needed three riders; in 1992, the requirement was relaxed to two riders to increase usage.
In the mid-1990s, HOV lanes with the same configuration opened on I-91 between exit 33 in Hartford and exit 40 in Windsor.
In June 2001, the lanes were extended 1.5 miles westward, allowing direct HOV access to the Founders Bridge (Route 2 westbound) leading into downtown Hartford. Also, the area at I-84 and Route 15 was restriped so that motorists from the Charter Oak Bridge can enter the HOV lane. These improvements led to a 25% increase in HOV lane usage during the peak hour and a 34% increase over the peak period - a good result.
Business Loop 84
In the 1960s and 1970s, there was apparently a signed Business Loop 84 in Newtown, extending from I-84 exit 9 along Route 25 and US 6 to I-84 exit 10. There's more information at AARoads: Interstate Business Loop 84. Business loops are common in many other states, but aside from BL 84 Connecticut has never had any.
Oh, what else. Yeah. Connecticut had a state route 84, whose
number was taken for I-84.