Interstate 395 is a lengthy route that leads north from Interstate 95 in southeastern Connecticut to Interstates 90 (Massachusetts Turnpike) and 290 at Auburn, Massachusetts. The mostly rural freeway follows a portion of the Connecticut Turnpike, extending the former toll road north from I-95 to its eastern spur (unsigned Connecticut 695) to U.S. 6 in the town of Killingly. The remainder of the route in Connecticut replaced Route 52.
As Interstate 395 north ends in Auburn, Interstate 290 east begins. Ramps connect the shared terminus with U.S. 20 (Washington Street) and an access road to the Mass Pike. Coinciding with a sign replacement project along the entire route of I-395 in Connecticut, all exit numbers were renumbered to use a mileage based system in 2015. This was the first freeway in the state to drop sequential based exit numbers.
Planning for the eventual Interstate 395 began as a new route for Massachusetts 12 in 1965. Redesignated Massachusetts 52 in 1967, work on the freeway began in 1965 at Interstate 90, with completion of the route between Webster southward to the state line by 1968. Building of the road by Eddy Pond however caused problems because of environmental concerns, delaying completion of the freeway in Massachusetts portion to 1977. Multi-state route 52 was upgraded to Interstate 395 by 1983.1