The A34 is closed near Abingdon this morning following a four car crash.
The collision occurred near the Milton Interchange, which has been plagued with delays over the last 24 hours due to a multiple traffic light failure.
Ice and freezing fog have exacerbated the problems, according to police.
The head of road policing for Thames Valley, Assistant Superintendent Henry Parsons, has warned drivers to avoid the area due to the icy conditions.
He said the road could be closed until at least 9.30am.
The A34 in Milton is closed and long delays are reported northbound at the Milton Interchange.
Queues are stretching back to the Chilton Interchange.
Oxfordshire Fire and Rescue service did not attend the incident.
It is not known how close to the traffic lights the collision happened or the extent of any injuries.