A motorcyclist was taken to hospital after colliding with a car on the A41, close to junction 9 of the M40, at Wendlebury.
Paramedics were called to the incident at 7.30am.
The accident happened on the northbound carriageway, causing delays to motorists as the road was closed temporarily to the outskirts of Bicester.
The male motorcyclist was taken to the John Radcliffe Hospital, in Oxford, for treatment to cuts and suspected broken bones, though his injuries are not thought to be life-threatening, said a police spokesman.
Police confirmed an arrest was made at the scene, but were unable to give any more details.
Paramedics were also called to another collision, on the A420 at Buckland, near Faringdon, at 7.55am.
Two car drivers were treated for minor injuries at the scene.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article