Roadworks are causing severe delays on Abingdon Road and across the city.
There is heavy traffic on A423 Southern Bypass between A34 (Hinksey Hill Interchange) and A4144 Abingdon Road (Kennington Roundabout) due to improvement works on the Kennington roundabout junction.
And there are temporary lights on Folly Bridge and Donnington Bridge due to water main works, which are adding to the problems.
The delays are also affecting the A40 into the city, which our reporter saying traffic was "crawling".
Oxford Bus Company said its services were delayed by up to an hour as a result, with some journeys terminating early.