All northbound lanes are now open and two of three southbound lanes remain closed on the M1 Pacific Motorway between Berowra and Mount Colah, following a fatal truck crash on Tuesday morning.
At 3pm, Live Traffic NSW was still urging motorists to exercise caution when traveling between the Central Coast and Sydney.
The M1 Pacific Motorway was closed between Berowra and Mount Colah.
Emergency services were called to the southbound lanes of the M1, near the Church Street overpass, about 2.30am.
Police said a body was found inside a truck that rolled and caught alight on the M1 at Mount Kuring Gai.
On arrival, officers found a B-double that had crashed into the medium strip and rolled before catching on fire, burning a load of wool it was transporting, police said.
A body, believed to be the driver, was found inside and is yet to be identified.
Officers from Kuring Gai Police Area Command have established a crime scene and have commenced a full investigation.
Traffic is being diverted around the crash site and motorists are being advised to avoid the area where possible.
Anyone with information about this incident is urged to contact Crime Stoppers on 1800 333 000 or online
At 7am, Church Street was still closed in Mount Kuring-Gai.
Investigations are continuing on site and the recovery operation is expected to continue throughout the morning peak.
People wishing to travel between the Central Coast and Sydney should either delay their journey, allow plenty of extra travel time due to increased volumes on the Pacific Highway or consider catching a train instead.
Additionally, buses in the area are delayed and disrupted with customers advised to allow extra travel time.
Southbound motorists are being diverted off the M1 at the Berowra Interchange to continue their journey via the Pacific Highway.
There is no southbound access to the M1 at Berowra via Windybanks Interchange.
Traffic on the M1 is queued around 8km from the Hawkesbury River through to the Berowra exit.
Traffic on the Pacific Hwy is queued around 17km from Cowan to Mount Colah.
Northbound motorists can no longer access the M1 from the Pacific Hwy or Pennant Hills Rd at Wahroonga. Motorists can use the Pacific Hwy via Hornsby and join the M1 at Berowra.
Traffic is starting to build on Pennant Hills Rd and the Pacific Hwy between Normanhurst and Hornsby.
