The M1 Princes Motorway is closed southbound between New Mount Pleasant Road and Mount Ousley Road at Mount Ousley due to a multi-vehicle crash.
Motorists are advised to avoid the area.
Light vehicles can use Picton Road and Mount Keira Road instead.
Alternatively, all vehicles under 19 metres in length can use Bulli Pass (Princes Highway) instead.
B-Doubles are being parked up.
Motorists already in the area should follow the direction of traffic crews and emergency services on site.
Traffic is heavy in both directions so motorists should allow plenty of extra travel time.
An extensive clean-up operation will need to take place before all lanes can reopen.