Trooper Christopher Kay says a Garda Security International truck was headed north when the driver lost control and struck a guardrail. The vehicle overturned near the exit for the Garden State Parkway.
Kay says the driver was ejected and pronounced dead at the scene.
Another guard, who was freed from the wreck, was taken to a hospital. His condition isn't known.
Kay says both men are 45 years old and from New York. No names have been released.
The accident caused traffic delays for about six hours.
The cause of the crash is under investigation.