A mini diesel tanker tipped over on the northwestern motorway on Wednesday. Emergency services were alerted just before 8am that the tanker had tipped on its side in the construction area between Waterview and St Lukes Rd. Fire Service northern communications shift manager Paul Radden says the accident occurred off the motorway and as a precaution an ambulance was called. ‘‘There were no persons trapped and no one was injured. Rubber necking could have slowed traffic down a bit,’’ he says.