Interstate 291 (abbreviated I-291, formerly known as the Springfield Expressway) is a 5.44-mile (8.75 km) connector highway in Massachusetts that links Interstate 91 in downtown Springfield with Interstate 90 (the Massachusetts Turnpike) in Chicopee. I-291 is roughly a northeast/southwest highway. It merges with I-91 at its southwestern terminus, via a flyover. The road meets the Mass Pike at its northeastern terminus. Getting onto the Pike from I-291 is straightforward, but getting from the Pike to I-291 requires a left turn at a stop light. I-291 travels directly through highly populated areas of Springfield, and passes under several overpasses. From its southwestern terminus to exit 5A, Interstate 291 is concurrent with U.S. Route 20.
I-291 is only 22.4 miles (36.0 km) from Interstate 291 in Connecticut, and there are no intervening Interstate Highway interchanges between them. It can be easy for travelers to become confused between the two highways.
Interstate 291 begins as a spur of Interstate 91 at Exit 8 in Springfield, concurrent with U.S. 20, which merges from the north. The two entry ramps from I-91 merge with each other after Exits 2A and 2B, where a sign for the beginning of I-291 east is posted. I-291 and U.S. 20 run eastbound concurrently until Exit 5A (U.S. 20 joins westbound at Exit 5), where U.S. 20 east leaves the highway for a junction with Route 20A. I-291 continues east into Chicopee, where it meets its eastern end at Exit 7, the interchange with the Massachusetts Turnpike (Interstate 90). This is an odd intersection; the mainline of I-291 ends at a stoplight, but I-291 east traffic can exit uninterrupted by way of a ramp to the Mass Pike. However, drivers coming from the Mass Pike must deal with this traffic light, as a left turn across the intersection is required to get on I-291 west.
The westbound interchange with I-91 is unusual in that the ramps for Exit 1A-B split before the ramps for Exits 2A-B do. Traffic bound for Exit 2A (Chestnut Street) must first take the ramp for Exit 1A (I-91 South), and traffic bound for Exit 2B (Dwight St.) must first take the ramp for Exit 1B (I-91 North).
Traffic bound for U.S. 20 West from I-291 takes Exit 1B. U.S. 20 does not actually join with I-91, but rather this exit splits, left for the on-ramp to I-91 North, the right to continue on the U.S. 20 access ramp.