The driver was travelling from Melbourne to Sydney when the incident took place, Acting Inspector David Cowell of Yass Police Station said on Friday morning.

Police have told the family, however, they are yet to release the driver's name, Acting Inspector Cowell said.

At approximately 4.40pm on April 23, emergency services were called to reports of a truck crash on the highway, approximately five kilometres east of Gunning.

Police were told a northbound prime mover crashed into a B-double, which was broken down in lane one. The cabin and engine of the prime mover engulfed in flames on impact.

The driver died on scene, while the driver of the broken-down truck was taken to hospital with minor injuries, on-scene paramedics said.

A Gunning Motors employee, Chevon Greene, said she spoke to someone who had been sent to the service station to get fuel for the truck driver that had broken down. The crash happened not long afterwards.

Both trucks were alight when the Rural Fire Service arrived on scene, Superintendent Peter Alley said. Fire and Rescue NSW also assisted with the fires.

Firefighters have not established a cause for the blaze, however, Superintendent Alley said he could only assume that the fuel tanks ruptured and there were sparks as a result of the impact.

The northbound lane was closed throughout the night, until 6am on April 24.

Up to twenty trucks close to the scene faced an overnight stay, unable to turn around in the northbound lane.

Drivers were seen supporting one another in the aftermath of the crash. Groups of drivers were talking through the incident and sharing food and water.

Gunning Motors remained open later than usual to assist traffic diverted through the village. Ms Greene said a few drivers who asked what had happened were saddened by the news when she told them.

The crash is under investigation and police are appealing for anyone who witnessed the incident to contact them.

Anyone with information about this incident is urged to contact Crime Stoppers: 1800 333 000 or https://nsw.crimestoppers.com.au. Information is treated in strict confidence. The public is reminded not to report crime via NSW Police social media pages.