According to city of Sugar Land officials, a man was riding his motorcycle on the southbound lanes of US-59 over the Brazos River just before 2 a.m. when he lost control and fell off of his bike.
That's when another vehicle on the roadway struck him, officials said.
The driver of that vehicle remained on the scene and is cooperating with police.
The motorcyclist was transported to the hospital via LifeFlight in critical condition.
All southbound lanes of US-59 were closed for several hours as crews investigated the scene. The freeway has since reopened.