Route 3 is a 14.48-mile-long (23.30 km) route connecting Middletown to the Glastonbury-East Hartford town line. It passes through the towns of Cromwell, Rocky Hill, Wethersfield, and Glastonbury. The northernmost 3 miles (4.8 km) of Route 3 is a freeway that was originally intended for the cancelled Interstate 491.
Route 3 begins at Route 66 in Middletown, and is a surface road for its first 11 miles (18 km) up to Wethersfield. After crossing into Cromwell, it intersects Route 372, which offers access to Route 9 just east of the intersection. After overpassing Route 9, it continues north into Rocky Hill and overpasses Interstate 91 without an interchange. After a brief concurrency with Route 160, it crosses into Wethersfield, where it meets the eastern end of Route 287 and crosses over Route 99. After the Silas Deane Highway (Route 99) intersection, it becomes a four-lane undivided expressway. At an interchange with Interstate 91, it becomes a four-lane divided freeway crosses the Connecticut River on the William H. Putnam Memorial Bridge into Glastonbury. The freeway has one exit for Main Street (via Glastonbury Boulevard northbound and Putnam Boulevard southbound) before ending at a trumpet interchange with the Route 2 expressway at the East Hartford town line.
Route 3 was established in 1941. It originally ran from West Street/Berlin Road in Cromwell, which was part of Route 72 at the time (now Route 372), to the Silas Deane Highway (Route 99) in Wethersfield.
In late 1958, as part of the planned Interstate 491 (a southeastern bypass of Hartford), a freeway from I-91 to Main Street in Glastonbury, crossing the Connecticut River on the Putnam Memorial Bridge, was opened. The Route 3 designation was temporarily extended along this freeway pending completion of I-491. In 1973, I-491 was cancelled due to local opposition and the Route 3 designation along this freeway segment became permanent. In the late 1980s, the freeway was extended so that it terminated at Route 2, rather than at Main Street.
In 1991, when the Route 9 freeway through Berlin and New Britain was completed, Route 72 was truncated to end at Route 9 in New Britain. The east–west portion of the old alignment of Route 72 was reassigned to an extended Route 372 (running along Berlin Road/West Street to end at Route 99 in Cromwell). The north–south portion of old Route 72 from Cromwell to Middletown (ending at Route 66) was reassigned to Route 3.
As part of an upcoming sign replacement project on Route 3 between I-91 and Route 2, new mile-based exit numbers will be added along that stretch of expressway.
