- Western Terminus:
- I-91 and Middletown Avenue (CT 17) in New Haven
- Eastern Terminus:
- Main Street (CT 154) in Deep River
- 25.91 miles
- New Haven, Middlesex
CT 80 is an east/west route in southern central Connecticut. It begins at I-91 in New Haven and runs east through East Haven, North Branford, Guilford, Madison, and Killingworth to end at Main Street (CT 154) in Deep River. The route takes on several different street names. The entire length is a two- to four-lane road with traffic lights.