The M6 motorway was closed for several hours earlier today (Thursday 24 July 2014) after pieces of concrete fell from a bridge that runs over it.Two vehicles were hit by the falling concrete – one suffering a shattered windscreen. One driver was uninjured, the other suffered cuts and abrasions to his face and head.The M6 southbound only was closed between junctions 16 and 17 following the incident. There is currently significant congestion and slow moving traffic in and around the area, which is likely to continue for some time.The motorway has now reopened after an inspection of the bridge cleared it as safe.Inspector Liz Cunningham of Cheshire Police said: "It is not an easy decision to close a significantly busy section of a key motorway network during peak rush hour, but our prime concern is always the safety of the public. Two vehicles had already been hit by pieces of concrete falling from the bridge, fortunately with no serious injuries, but it was necessary to close the motorway and take expert advice on the bridge's ongoing safety before the motorway could be reopened and traffic allowed to pass under and across it.”An enquiry will now take place, led by the Highways Agency, to determine what caused pieces of concrete from the bridge to come loose.