The date for closure has now been moved to July 23rd, 2014.
The OCC site for these roadworks can be accessed here https://www.oxfordshire.gov.uk/cms/content/a420-shrivenham-bypass-major-maintenance
All HGVs (over 7.5t), except local firms and deliveries, should be diverted via A34/M4. The diversionary route from Swindon to Oxford is through Shrivenham and along Faringdon Road at the top of Watchfield with a reduced speed limit along Faringdon Road of 30mph. Oxford to Swindon will be advised to go through Longcot then Shrivenham. An enforced one way system was not favoured by the emergency services. Diversionary routes cannot be forced so it is likely that those with local knowledge and/or SatNavs will opt for the shortest route along Watchfield’s Faringdon Road. The provision of a temporary crossing point has been raised several times. Further revisions may occur prior to the work beginning and Oxfordshire County Council are responsible for publicising the closure and diversionary routes to local communities.
All pot holes along the diversionary route should be filled prior to the diversion and repaired afterwards. If you spot a pothole that has not been identified by chalk/paint, please report it on www.fixmystreet.co.uk