A man stabbed during a road-rage incident on a busy Sydney motorway tried to drive himself to hospital before being forced to call paramedics.
The 42-year-old man needed emergency surgery after he says a younger man in a Toyota Corolla threw something at his ute and both drivers stopped on the Westlink M7 near Glendenning on Friday, police say.
Both had a brief argument outside their vehicles before the Corolla driver, aged about 20, stabbed the older man in the abdomen and drove off at high speed.
The injured man tried to drive to a nearby hospital before deciding to pull over in Doonside, where a passenger called for an ambulance.
Despite the incident stopping traffic on a busy motorway about 4.30pm, few witnesses had come forward to police by late on Saturday morning.
Investigators have urged witnesses offer copies of dashcam footage and the Corolla driver come forward to tell his side of the story.
Video from the motorway operator is also being sought.
It's unclear whether the two men knew each other.
Sergeant Steve Vuletas described the incident as "alarming" .
"You'd like to hope people take it easy on the roads and simply just get home avoiding incidents like this," he told reporters.
"Certainly never stop on a busy motorway and resolve your disputes - on the M7 or any road for that matter.
"Find a safe place, whether that be a police station or another place you find safe, and contact triple zero."
The Hilux driver remains in a stable condition in Westmead Hospital and is expected to make a full recovery.
© AAP 2018