Update:
Firefighters have contained a truck fire at Rockdale.
The truck was driven from the scene about 2pm and a clean-up operation to remove the rubbish from Bay Street commenced immediately.
Westbound traffic on Bay Street is being diverted before the Princes Highway intersection but the highway remains open to traffic.
Earlier:
Firefighters are working to extinguishing a truck fire at Rockdale this afternoon.
Emergency services were called to the Princes Highway at Bay Street just before noon after reports a semi-trailer load had caught fire.
Firefighters are working to gain access to the load which is believed to be timber and waste building materials.
Drivers are advised to avoid the area with Bay Street closed westbound between West Botany Street and the Princes Highway.