All southbound lanes of U.S. 75 were closed for more than two hours Wednesday night after a crash near Spring Valley Road.
Richardson police said a motorcycle collided with a car, causing a crash that held up traffic for hours.
The two people riding the motorcycle were taken to the hospital with serious injuries.
While the roadway was closed, officers diverted traffic onto the Arapaho Road service road. The crash caused major traffic backups on an already busy travel day due to the Thanksgiving holiday.
The southbound lanes of U.S. 75 were reopened shortly after 8:30 p.m.
It's still unknown what caused the crash.
