A cracked bridge support has forced the closure of the M4 motorway in west London.
The Highways Agency said it closed the Boston Manor Viaduct, near junction two of the motorway after a crack in a highly stressed zone over the bridge support was found during a wider repair programme.
It said: “This requires a unique repair solution, which we are progressing, which requires us to keep the viaduct closed until the repair is complete.”
The fault was discovered just months after Transport for London made the unprecedented decision to close the Hammersmith Flyover, one of the busiest roads out of London, following the discovery of a serious structural defect.
Traffic is being diverted onto local roads around junctions two and three and drivers have been advised to take alternative routes.