A serious accident on the Belt Parkway backed up traffic for hours early Sunday morning.

Police say the accident happened just after 4 a.m. and that only the driver was in the car at the time.

Sources told News 12 the car overturned after crashing through a guardrail between the Pennsylvania Avenue and Erskine Street exits. That car then overturned again into the woods.

They say the driver was stuck in the car for some time.

Police told News 12 they took that 33-year-old driver to Brookdale Hospital with leg injuries. He is expected to survive.

The traffic spread across two boroughs, Brooklyn and Queens, as investigators closed down a lane of the westbound Belt Parkway.

As of 8 a.m., the westbound Belt Parkway started to move again.

The car has since been towed from the scene.