Crashes delay southbound drivers, prepare for holiday traffic to the north

Emergency services were called to the scene of a crash on the M1 at Berowra early on Friday morning after reports multiple vehicles had crashed.

All southbound lanes were closed before 5am and diversions were in place before all lanes reopened by about 9.30am.

However, a second multi-vehicle crash just a few kilometres south on the M1 at Mount Kuring-gai had occurred by about 10am.

A Transport Management Centre (TMC) spokesperson said traffic that had built up during the first crash was then stuck behind the second crash.

All southbound lanes of the M1 had reopened by about 1pm on July 5.

Debris had been cleared from the road at that time, and two tow trucks had moved the vehicles involved in the crash.

Traffic has been heavy in the area all day and the build-up from the two crashes was delaying commuters into the afternoon.

Newcastle drivers headed south reported the trip to the other side of Sydney took several hours longer than usual on Friday.

The TMC urged drivers in the area to "expect significant delays" but said traffic should be clearing now that the M1 had returned to normal.

The TMC spokesperson said northbound traffic on the M1 was flowing well on Friday, though it could get busier with school holidays starting on Saturday.

People headed north have been warned to expect heavier traffic than usual in the Hexham area into the weekend due to holiday traffic.

"High volumes of holiday traffic are expected approaching Beresfield, Tarro, Hexham, Heatherbrae and beyond, during peak travel periods," an alert from Live Traffic NSW said.

If you're catching public transport, be aware trains on the Hunter line are not running from 5.30pm due to ongoing illegal protest activity, and there are delays on the Central Coast Newcastle line due to earlier flooding at Cockle Creek.