Location : The M4 westbound between junctions J15 and J16 . Reason : Accident involving an overturned vehicle. Status : Currently Active. Time To Clear : The event is expected to clear between 12:45 and 13:00 on 26 July 2021. Return To Normal : Normal traffic conditions are expected between 12:45 and 13:00 on 26 July 2021. Lanes Closed : There are lane closures. Previous Reason : Following an earlier accident.