Drivers have been facing delays in the Thame area following an accident on the A329.
One vehicle was involved, with police called to the scene on the A329 Rycote Lane at 11.39am.
The road is now closed in both directions.
A Thames Valley Police spokesman confirmed that police officers are attending and the road is still closed.
The accident happened between the junction with Oxford Road and the A40 London Road.
It is not yet known if the driver has been injured.