Traffic is gridlocked on the M4 following a serious accident this afternoon.
Fire crews from Wokingham and Maidenhead are attending the crash.
It happened between junction 10 for Wokingham and junction 8/9 for Maidenhead on the eastbound carriageway.
Delays are being caused on both the eastbound and westbound carriageways on the motorway.
UPDATE 3.05pm: All lanes have now been reopened but traffic is still moving slowly in both directions.
Top Ten Articles
The Met Office has issued a yellow alert for Windsor and Maidenhead, Slough and Wokingham, warning that rain moving eastwards across the south of the country may turn to snow in some places.