List of Interstate Highways in Connecticut

Dwight D. Eisenhower National System of Interstate and Defense Highways
Standard Interstate Highway signs in Connecticut
All Interstate Highways in Connecticut
System information
Length:	446.33 mi (718.30 km)
Notes:	Interstate Highways in Connecticut maintained by ConnDOT
Highway names
Interstates:	Interstate X
US Highways:	U.S. Route X
State:	State Route X
System links
Routes in Connecticut Interstate U.S. State SSR SR

Interstate Highways in the U.S. state of Connecticut run a total of 446.33 miles (718.30 km). Connecticut has three primary highways and five auxiliary highways. Most of the highways are maintained by the Connecticut Department of Transportation, with the exception of Interstate 684, which is maintained by the New York State DOT.

In 1957, Connecticut received approval for the routes of its three primary Interstate highways: I-84, I-91, and I-95. This plan was extended in 1959 to include I-291 and I-491. The first Interstate Highway signs were installed on a completed section of I-91 north of Hartford in 1961. The primary interstates were all completed by 1969 after the last section of I-84 opened between Farmington and Plainville. The rest of the highways were built or renumbered to their current designations by 1994 when a five-mile section of I-291 opened 35 years behind schedule. Connecticut was one of the last states in the US to raise its maximum speed limit to 65 mph (105 km/h), which it did in 1998.

Though parts of the Interstate Highway System in Connecticut were once tolled, no toll booths exist today. All tolls on I-95 were removed in 1985 after a runaway truck ran into a line of cars waiting at a booth, killing seven.