Drivers on Oxford’s ring road and the A34 are still being delayed by an overturned lorry which has not yet been removed from the carriageway.
The accident happened at about 7am at the Kennington roundabout, causing tailbacks on the Southern bypass, Abingdon Road and other major routes into the city.
The lorry overturned just after it had left the Kennington roundabout to head for the Hinksey Hill interchange.
David Staines, a spokesman for Thames Valley Police, said staff recovering the vehicle estimated it would take until about 5pm to complete the task.
He added: "That means congestion could continue into the rush-hour."
James Wright, a spokesman for the Highways Agency, said: "The overturned lorry has caused serious delays on the A34, with particular problems on the southbound carriageway.
"Traffic has tailed back to Islip, and has been very slow in the Wolvercote area."
A spokesman for South Central Ambulance Service said staff were not required to attend the incident.
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 The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.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 here