All southbound lanes reopen on M1 north of Sydney following fiery truck crash

All southbound lanes on the M1 have reopened after a truck crashed into a wall and caught fire north of Sydney.

Authorities said the truck hit a rock wall and burst into flames at Mount White just after 5am.

All southbound lanes of the M1 were closed near Jolls Bridge, but have since reopened.

A reduced speed limit of 80km/h has been implemented due to some road surface damage.

There is currently a 10km backlog of traffic leading up to where the crash occurred.

The truck driver was airlifted to Sydney’s Westmead Hospital with serious spinal, pelvic and leg injuries.

The Transport Management Centre is still urging motorists travelling between the Central Coast and Sydney to consider catching a train on the Central Coast and Newcastle Line to save time and ease congestion.