Police say two vehicles collided near Greenpoint on the Brooklyn-Queens Expressway Saturday morning.
It happened just before 8 a.m. on the eastbound side of the BQE near Meeker Avenue and Humboldt Street.
One of the vehicles slammed into the guardrail and flew off the elevated roadway onto the street below.
The driver was a man in his 20s. He was extricated from the vehicle and taken to Bellevue Hospital where he is recovering from multiple injuries.
Sources say he is an off-duty police officer.
No one on the ground was hurt.
The driver of the other vehicle suffered minor burns and was taken to Elmhurst Hospital.
Police are still investigating the cause of the accident.