The Highways Agency said it decided to keep the Boston Manor Viaduct closed because during works it found a crack in a "sensitive location", which requires it to be kept closed until it is repaired.
Diversion on the A312 and the A4. Drivers are being advised to allow extra time for their journeys.
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Cloudy and breezy for much of the day. Rain and stronger winds arriving tonight.
A mostly dry but cloudy morning. Heavy rain and stronger winds this evening.
Another cloudy and breezy day tomorrow. Turning windy with rain arriving tomorrow evening.