It happened around 2am on Richmond Avenue near Fondren.
According to police, the man was driving west on Richmond when he went off the road and hit a palm tree, knocking it over.
Investigators said he then got out of the vehicle, walked into the traffic and was hit by a car.
He was taken to Ben Taub General Hospital in critical condition. Police said he may have been intoxicated, but there was no physical evidence at the scene to prove that theory.
The driver of the car that struck him passed a field sobriety test and will not face charges.