Witnesses said the pedestrian had made it about halfway through the crosswalk when the traffic light changed to green, giving the driver the right of way.
"I heard a loud screeching noise, which sounded like tires locking up, and then I heard a loud thud, which sounded like it hit somebody," said witness Ryan Smith.
Smith said he saw a man lying face down, so his instincts told him to run over and help.
The driver stopped about a quarter-mile after hitting the pedestrian.
Books that the victim was carrying were scattered across the street, but police have not said if the victim was a student. The victim, who has not been identified, is in serious condition on Monday.
The driver has not been charged because authorities believe the incident was an unfortunate accident.
Police continue to investigate the cause of the accident.