- Southern Terminus:
- Hutchinson Parkway and King Street (NY 120A) at the New York-Connecticut state line
- Northern Terminus:
- Yankee Expressway (I-84) in East Hartford
- 83.53 miles
- Fairfield, New Haven, Hartford
At the New York-Connecticut state line, the Hutchinson Parkway becomes the Merritt Parkway and takes on the designation of CT 15. It runs northeast, parallel to the Connecticut Turnpike (I-95), through Fairfield County. The Merritt Parkway is well-known as a scenic parkway. In New Haven County, CT 15 changes name to become the Wilbur Cross Parkway. It continues northeast until the vicinity of New Haven. While the Connecticut Turnpike runs east through New Haven, the Wilbur Cross Parkway curves to the north and runs parallel to I-91. In Meriden, the Wilbur Cross Parkway touches I-91 and serves as its frontage roads for a short distance. Then, it splits off and curves back to the west. After about a mile, it merges with US 5 to form the Berlin Turnpike. Unlike the Merritt Parkway and the Wilbur Cross Parkway, the Berlin Turnpike has traffic lights. CT 15 continues north along the Berlin Turnpike to the vicinity of Hartford, where it becomes a limited-access highway again. Here, it is called the Wilbur Cross Highway. CT 15 ends at the Yankee Expressway (I-84) in East Hartford.