UPDATE 2pm
Traffic has eased on the M1 Princes Motorway after a car fire near Heathcote on Wednesday.
Southbound traffic was heavy during the incident, just before noon.
All lanes have reopened and traffic has returned to normal.
It's understood the car on fire was a dual cab ute.
Emergency services and Transport for NSW were at the scene.
No injuries have been reported.
EARLIER
Firefighters have rushed towards Helensburgh to extinguish a car fire on the M1 Princes Motorway.
Southbound traffic is heavy about two kilometres south of Helensburgh due to the fire.
Motorists are only able to pass the incident via the breakdown lane.
It's understood the car on fire is a dual cab ute.
Emergency services and Transport for NSW are at the scene.
No injuries have been reported.