The A4095 near North Leigh was shut in both directions following a reported road accident, with queues forming around the affected area.
AA said traffic was backing up because of the collision, which occurred between Park Road and Akeman Road.
An AA map identified the location of the incident.
Local councillor Liam Walker said the collision at the point where Park Road meets Estelle Manor had caused lengthy delays on the A4095.
Drivers affected by the closure were advised to consider another route.
Thames Valley Police was contacted for comment.
AA continued to report that the road near North Leigh remained closed.
Despite the absence of vehicles in the surrounding area, the closure was still being shown on AA’s traffic information.
The road later appeared to have reopened, bringing the live coverage of the incident to a close.