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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Representatives of Surrey Police have paid respects to those affected by the bomb at Manchester Arena, and encouraged public vigilance.
Tuesday Evening's Pollen Forecast
Tuesday afternoon's weather for the west of the region