West Yorkshire Police are appealing for witnesses to a collision on the A629 Aire Valley Trunk Road which closed the road all day on Tuesday.
Officers say it happened at about 8.56am when a Volvo single decker bus was in collision with a John Deere tractor on the A629 between the Steeton and Keighley roundabouts, close to the golf club.
Both vehicles were travelling towards Keighley at the time of the collision.
The bus driver, a 52-year-old man, was taken to hospital where he was found to have suffered serious injuries.
The tractor driver was uninjured.
West Yorkshire Police's Roads Policing Unit is investigating the collision and would like to hear from anyone who witnessed it, or who may have dash cam footage that will assist with investigation work.
The unit can be contacted on 101, or by using the 101LiveChat facility on the West Yorkshire Police website.
The log reference is 0361 of 7th March.
MAJOR COLLISION involving a school bus blocks a busy bypass continues to close the road in both direction this afternoon.
— YappApp (@YappAppLtd) March 7, 2023
The A629 in Bradford is closed in both directions this morning following a serious crash involving a school bus.
The A629 has been closed in both… pic.twitter.com/V5kRj3hStm