Route 66 officially begins at
I-91 in Meriden as the extension of
I-691, which officially ends at its interchange with
I-91. It runs as a four-lane
freeway for about into the town of
Middlefield, where it becomes a four-lane surface road. In Middlefield, it has junctions with the northern end of
Route 147, and the southern end of
Route 217. It then enters Middletown and becomes Washington Street, where it has junctions with the northern end of
Route 157 and the southern end of
Route 3 before passing by
Wesleyan University and entering the downtown area. Route 66 then turns onto Main Street, as Washington Street becomes SR 545, providing southbound access to the
Route 9 expressway. At the north end of Main Street, it intersects
Route 17. Southbound Route 17 provides access to both directions of Route 9, while northbound Route 17 joins Route 66 to cross the
Connecticut River on the
Arrigoni Bridge into
Portland. Immediately east of the bridge, it meets the southern end of
Route 17A, which leads to Portland center. After Route 17 leaves to the north, Route 66 narrows to two lanes and follows the east shore of the Connecticut River into
East Hampton. It passes the northern end of
Route 151, and bends northeast as it intersects the western end of
Route 16. In the center of town, it meets the northern end of
Route 196, then crosses into
Marlborough. Here, it has a junction with the
Route 2 freeway at Exit 15 (old Exit 13). It then passes into
Hebron, Connecticut, where it has junctions with Routes
85 and
316 in the center of town. It then enters
Columbia, intersecting
Route 87 before reaching a junction with
US 6 at the western end of the Willimantic bypass. Route 66 turns east as a collector of local traffic headed for
Willimantic. In Willimantic, it has a 0.74 mile concurrency with
Route 32, and intersects the southern end of
Route 195, and the western end of
Route 14. It then turns north-northeastward and continues to US 6 at the east end of the Willimantic bypass, where Route 66 ends and US 6 assumes the roadway. From US 6 in Columbia to the end in Windham, Route 66 is designated the
Grand Army of the Republic Highway. The easternmost of the route is named
Boston Post Road and was part of the former
mail route. == History ==