Graves had picked the couple up from their Hightstown home around 3 a.m. for a trip to the airport, police said. The couple was wearing their seatbelts.
Graves also was taken to the hospital, but his condition was unknown as of this afternoon. He worked for a Trenton-based company. Authorities didn't have the name of the company.
Police said the two vehicles collided as the trailer reversed out of a construction site onto Route 130 South.
Graves veered left to avoid the flatbed, but the front of the limousine collided with flatbed's right rear wheels, police said. When police arrived at the scene they found the limo wedged against the right rear tires of the trailer.
The driver of the truck, Gregg L. Matthews, 42, of Howell, N.J., was not injured. He had been delivering equipment to a nearby construction site at the time. He was released after speaking with detectives.
The Mission Fire Company and Hope Hose First Aid Squad assisted in transporting the injured.
Monroe Danbury and Graves, the limo driver, were taken to Robert Wood Johnson University Hospital in Hamilton.
Danbury was transferred to Capital Health Fuld campus, where he died during surgery, according to police.
