U.S. Route 6 (US 6) within the state of Connecticut runs for 116.33 miles (187.21 km) from the New York state line near Danbury to the Rhode Island state line in Killingly. West of Hartford, the route either closely parallels or runs along Interstate 84 (I-84), which has largely supplanted US 6 as a through route in western Connecticut. East of Hartford, US 6 serves as a primary route for travel between Hartford and Providence.