Leroy Samuel, 22, who lived in Brooklyn, drove under a flatbed truck Tuesday. His passenger, a 22-year-old woman, survived, although she was taken to a hospital.
Joseph Vega told the New York Post he was cycling to work when he saw a car driving down an exit from the Brooklyn-Queens Expressway at 70 to 80 miles an hour.
"Highway patrol was chasing him," Vega said. "When I went to see what happened to the driver, he had no head. His head was in the back seat. It was horrible."
Police said Samuel took off when a police officer tried to pull him over for a traffic infraction on the expressway in Brooklyn.