CARY — The driver of an SUV that crashed into the rear of a truck on eastbound Interstate 40 early this morning ran off after the accident, police said.

The driver of a box truck was headed east near the Harrison Avenue interchange at about 60 mph when the truck was hit from behind at about 3 a.m., he told police. He was not hurt.

An off-duty Durham police officer was the first to report the accident after he came up on the car in the second lane of the interstate with no lights on, Cary officers reported.

The car, a Lexus sport utility vehicle, is owned by a woman in Burlington, police said, and she told them she was trying to determine if one of her children was using the car.

Police were unsure if the car driver was hurt. Only the driver-side airbag had inflated, they said, and they think the operator was alone at the time.

The front end of the Lexus was crushed by having gone under the truck.

Police said it appeared that the car had been traveling significantly faster than the truck.