According to Suffolk County police, Gary Johnson, 55, of Dix Hills, was crossing the Montauk at around 6:30 a.m. when he was hit by a Ford Mustang.
The driver, identified as 39-year-old Nancy Mecca of West Islip, remained at the scene until authorities arrived.
Johnson was transported to nearby Good Samaritan Hospital Medical Center where he was pronounced dead. Mecca was also treated for minor injuries.
Mecca has not yet been charged as the investigation into the incident continues.
Police are asking anyone with information about the incident to call Crime Stoppers at 800-220-8477. All calls will remain confidential.
The fatal accident prompted authorities to close the road in both directions for nearly four hours, sparking major traffic headaches for commuters during the morning rush hour.