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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Santa is not the only one who has an epic journey to make on Christmas Eve. A Sussex man is to cycle 500 kms to raise money for charity.
James Wright has the forecast for tonight and tomorrow in the west of the region.
James Wright has the forecast for tonight and tomorrow in the east of the region.