- Western Terminus:
- Main Street (CT 66) and Washington Street (CT 66) in Middletown
- Eastern Terminus:
- CT 9/CT 17 in Middletown
- 0.15 miles
Washington Street is the major east/west road in Middletown. For most of its length, Washington Street is part of CT 66. However, one block west of the CT 9/CT 17 expressway, CT 66 turns north onto Main Street in order to reach the Arrigoni Bridge. The remaining block of Washington Street has the unsigned designation of SR 545. It serves as a connector between CT 66 and the expressway.