The car drove off a Route 287 exit ramp, ejecting all three occupants.
The crash occurred just before 3:15 a.m. Friday. The car came to rest on its hood deep into nearby woods.
State police say the right front seat passenger, 22-year-old Richard Galdamez of Piscataway, was the only survivor. He was listed in serious condition at Morristown Memorial Hospital.
The driver, 25-year-old Francisco Guevera of South Plainfield, and 24-year-old passenger Daniela Rodriguez of Franklin, were killed. State police say they were killed when the car rolled over on them.