Thames Valley Police Road Policing Unit has confirmed an accident has occurred after the road was closed due to the icy conditions.
The A421 is closed both ways due to an accident. Two cars are believed to involved between Bottledump Roundabout and Whaddon Road.
The traffic is reported to be coping well.
The road closure comes after the Met Office has issued multiple weather and flood warnings for the area yesterday (30/01).
Thames Valley Police tweeted a warning to local drivers, they said: “Road closures are in place for a reason, please do not ignore them.”
