Dominic Brad, 54, of Hartford, Connecticut, was hit by a Toyota Corolla just after 2 a.m. near mile marker 4.8, Springfield police said.
Officers shut down I-91 South for hours as they cleaned, cleared, and investigated the crash. The road re-opened to normal traffic around 6 p.m.
Officers are investigating the circumstances that led up to the crash.
Click here to follow Daily Voice Holyoke and receive free news updates.