Never completed, Interstate 284 would have run about 5 miles from the I-84/CT 2 interchange north to I-291 in East Hartford. The exit 56 ramps at I-84 connect to a very short expressway (unsigned SR 500) ending at Governor Street. This was to continue north as I-284.
I-284 was cancelled in 1983 because of environmental concerns. A smaller alternative, the Prospect Street Bypass, was cancelled in 1994 for the same reasons.
An expressway paralleling the Connecticut River to the east had been planned since the 1950s. Even as the East Hartford - Glastonbury Expressway was under construction in 1951, an extension northward was proposed, passing under the Charter Oak Bridge and bypassing downtown East Hartford.
In 1963, the state unveiled a plan to relocated US 5 as a four-lane expressway from I-84 in East Hartford to I-91 in East Windsor. When the "Mixmaster" five-way interchange at I-84 and CT 2 opened in October 1965, connecting ramps were made for this expressway, although no funds were available to continue it northward at the time. To this day, the short SR 500 expressway from Exit 56 ends unceremoniously at Governor Street. (Though one wonders what sort of ceremony would be appropriate.)
In 1967, the state legislature passed a special act providing for a "relocation of United States Route 5 from south of Governor Street to the vicinity of King Street, not exceeding two million dollars for engineering and acquisition of right of way." (King Street, north of East Hartford center, is where Main Street and US 5 diverge.) The full East Hartford to East Windsor plan was added to the Capitol Region Planning Agency's 155-mile Year 2000 expressway plan.
In 1969, the legislature amended the act, increasing the amount to $5 million. The Department of Transportation, looking at a larger scope, realized the need for a north-south highway east of the river, and proposed an expressway to connect to I-91 at East Windsor. The segment connecting to I-291 (then called state route 291) would be an interim step.
The 1975 Master Transportation plan recommended constructing the 2.9-mile link from Governor Street to (the proposed) I-291, at a cost of $30.5 million. The expressway was still called Route 5.
In the early 1980s, opposition to the plan increased because of concerns over environmental damage should the highway be built. On September 16, 1983, the state officially cancelled I-284.
The Prospect Street Bypass
Thru traffic skirting downtown East Hartford is a problem on Prospect Street, a two-lane road leading from the Governor Street terminus north and east to Main Street.
In the wake of the I-284 cancellation, the DOT explored less ambitious traffic relief in the form of a Prospect Street Bypass, extending north from the SR 500 terminus, keeping west of Prospect Street, and ending at the Main Street/King Street (US 5) intersection. These were the same termini as in the 1967 plan.
This road was in the 1990 transportation plan, and studied in 1994, but the DOT cancelled it because of potential impacts in the area.
Another suggestion for the number
In 1980, a Hartford traffic study suggested using the I-284 designation on Route 3 and Route 2, between I-91 in Wethersfield and I-84 in East Hartford. The reasoning: a continuous interstate number would be more easy and reassuring to follow, and motorists could bypass the Charter Oak and Founders bridges.
The study's suggestion was not taken up. (At the time, the I-284 designation was still active for the US 5 relocation.)
and Circulation Plan". Submitted to Planning and Zoning Commission, Town of East Hartford, Conn.; May 2002.