|Maintained by MassHighway|
|Length:||4.86 mi (7.82 km)|
|Existed:||1970 – present|
|South end:||I‑91 in Chicopee, MA|
|North end:||High Street in Holyoke, MA|
Interstate 391 (abbreviated I-391) is an Auxiliary Interstate Highway located entirely within the U.S. State of Massachusetts. It runs from the I-91/I-391 interchange in Chicopee to the center of Holyoke, a distance of about 4.86 mi (7.82 km). It runs near the Connecticut River throughout its journey in Chicopee, and crosses into Holyoke and abruptly ends at High Street 0.4 miles (0.64 km) south of U.S. Route 202.
Interstate 391 begins at an interchange with I-91 (at Exit 12) in southern Chicopee, just north of the Atwater Park and the Calvary Cemetery. Initially running parallel to the Connecticut River, it intersects with Route 116 in Chicopee center and crosses the Chicopee River. I-391 then has another junction with Route 116 in the Sandy Hill section of town, and in less than one mile (1.6 km), it crosses underneath the Massachusetts Turnpike without an interchange. I-391 continues north through the rest of northern Chicopee, intersecting Route 141 along the way and then passing just east of Rivers Park. I-391 then crosses the Connecticut River into the city of Holyoke, where it has two closely spaced exits for local streets in the town. I-391 officially comes to an end at High Street in Holyoke, with the road continuing as Resnic Boulevard, which connects to US 202 after 0.4 miles (0.64 km).
Plans for the highway originated from the Master Highway Plan for the Springfield Metropolitan Area in 1953, which planned for a "major street improvement" to Route 116. By the 1960s, freeway access was needed between Chicopee and Holyoke to improve traffic flow which prompted a spur route of Interstate 91 to be built. I-391's planned six lanes were built to handle up to 50,000 vehicles every day, and the total cost of the proposed highway was estimated at about $35 million. In 1965, an alignment of the highway had been set, along with two alternative alignments. Construction for Interstate 391 began in 1967 with a short 0.75 mi (1.21 km) long highway, which was completed in 1970. After years of no progress, construction started again in 1978. The highway was completed in 1982 after about 15 years of planning and construction.
All interchanges will be renumbered to mileage-based numbers under a project scheduled to start in 2016. However, this project has now been indefinitely postponed. The entire route is in Hampden County. 
|Chicopee||0.065||0.105||1A||I‑91 south – Springfield, Hartford, CT|
|0.626||1.007||1B||I‑91 north – Greenfield|
|0.952||1.532||2||Route 116 – Chicopee Center||To Elms College|
|1.900||3.058||3||Route 116 – Westover ARB, Willimansett|
|3.860||6.212||4||Route 141 – Chicopee Falls, Willimansett||South end of Former overlap with Route 141; Split into exits 4A (east) and 4B (west) southbound|
|Connecticut River||4.509||7.257||Vietnam Veterans Memorial Bridge|
|Holyoke||4.593||7.392||5||Main Street||Former Route 141 north; northbound exit and southbound entrance|
|4.940||7.950||6||Commercial Street||Northbound exit and southbound entrance|
|5.160||8.304||–||High Street||At-grade intersection; northern terminus|
|1.000 mi = 1.609 km; 1.000 km = 0.621 mi
- itd. "MassGIS EOT-OTP Roads data layer". Administration and Finance. Retrieved 5 October 2014.
- Google (2008-05-26). "overview map of I-391" (Map). Google Maps. Google. Retrieved 2008-05-26.
- Bostonroads.com. "Interstate 391 (Massachusetts)". Retrieved 2008-05-26.
- Commonwealth of Massachusetts (2015). "COMMBUYS - Bid Solicitation FAP# HSIP-002S(874) Exit Signage Conversion to Milepost-Based Numbering System along Various Interstates, Routes and the Lowell Connector". Retrieved January 5, 2016.
- MassDOT Planning Division. "Massachusetts Route Log Application". Massachusetts Department of Transportation. Retrieved August 21, 2014.