Tynielle Silvera, 18, of Amityville was pronounced dead at the scene, police said.
He was arrested at the scene and charged with driving while intoxicated, police said. He is scheduled for arraignment Thursday in First District Court in Central Islip.
The Chevrolet was impounded for a safety check while police continue the investigation.
Police could not immediately say why Silvera was walking in the roadway and also did not release a blood-alcohol content reading for Serwan.
They are asking anyone who has information regarding this incident to call Crime Stoppers at 1-800-220-TIPS. All calls will remain confidential.