Truck bursts into flames on Sydney motorway

A truck fire at Revesby in Sydney's south-west has shut down multiple lanes of a major motorway.

Two of three westbound lanes are closed on the M5 approaching Beaconsfield Street.

All city-bound lanes are open but traffic is still slowing as it passes the accident site.

READ MORE: Sydney school to stay closed after boy dies under lift

Westbound traffic is backed up to Riverwood, and citybound to Prestons.

Drivers are advised to allow plenty of extra travel time and exercise caution as smoke in the area may affect visibility.

They are also urged to follow the directions of emergency services on site.

It's understood the truck was full of recycled rubbish.