A man drove off a railway overpass at Port Kembla, landing on the tracks below, minutes after allegedly avoiding an RBT stop.
Highway patrol officers were conducting random breath tests at Cringila along the southbound side of Five Islands Road on Saturday night.
According to police, at around 9.40pm a silver four-door sedan slowed down at the RBT site but did not stop.
Police did not immediately pursue the vehicle but a short time later went looking for it.
Just south of the Flinders Street intersection police noticed the guardrail on a railway overpass had been significantly damaged.
They found the crumpled sedan lying on the tracks below.
It is understood the train tracks were part of an internal industrial line rather than a passenger line.
Papers and other debris believed to be from the vehicle littered the roadside.
There was no one in the car and police began a search of the surrounding area to try and find the driver.
A shirtless 20-year-old man was found in nearby bush roughly an hour later and treated by ambulance officers for lacerations to his back.
He was taken by ambulance to Wollongong Hospital before later being transferred to St George Hospital where he remains in a stable condition.