The turnpike opened in 1957, and it was designated as part of the Interstate Highway System in 1959. The original western terminus of the turnpike was located at Route 102 in West Stockbridge before I-90 had been completed in New York state. The turnpike intersects with several Interstate Highways as it traverses the state, including I-91 in West Springfield; I-291 in Chicopee; I-84 in Sturbridge; the junction of I-290 and I-395 in Auburn; and I-495 in Hopkinton. The eastern terminus of the turnpike was originally at I-95 in Weston, it has been extended several times: to Allston in 1964, to the Central Artery (designated as I-93, US 1, and Route 3) in Downtown Boston in 1965, and to its current terminus in East Boston in 2003 as part of the "Big Dig" megaproject. There are two auxiliary Interstate Highways in Massachusetts for I-90, those being I-190 and I-290.