One man has been airlifted to hospital after a crash on the A64 at Copmanthorpe.
The incident happened at around 1.10pm on the slip road towards Leeds and involved an articulated lorry and a car.
The injured man has believed to have serious, but not life-threatening, injuries.
A North Yorkshire Police statement at 2.26pm said:
A number of other people have been taken to York Hospital by road ambulance with serious but not life threatening injuries.
Drivers are urged the avoid the area as the road is still shut.
Four fire crews, from York, Acomb, Huntington and Tadcaster, also went to the scene.
Closures are in place preventing traffic entering the A64 from the A1237 and exiting from the A1036 direction.
Anyone who witnessed the incident is asked to contact police on 101, quoting the number 0221 of 30 April.