The State Transport Minister has called on the driver who rammed into a south Sydney railway signal box this morning to turn themselves in, as officials warn the damage could take days to repair.

Key points: A signal relay room was damaged by a car crash at Riverwood

A signal relay room was damaged by a car crash at Riverwood Sydney Trains said there will be "major delays" on the airport line, with others also impacted

Sydney Trains said there will be "major delays" on the airport line, with others also impacted NSW Police said the driver left the scene before officers arrived

Transport officials said the damage sparked train delays which are expected to continue into the afternoon.

The chaos was trigged by a white Honda Accord that ploughed through a wire fence and into the front of a metal box at Riverwood before 2:00am this morning.

When police arrived at the crash site, the driver was nowhere to be found. The damage resulted in major delays being felt across the T8 Airport and south lines.

Transport Minister Andrew Constance has urged the driver to turn himself in.

"You left the scene, you had a reason for doing, though," Mr Constance said.

"You might want to explain that to the hundreds of thousands of commuters across Sydney that are going to be potentially impacted by this."

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Earlier in the day, Sydney trains chief Howard Collins said the incident caused hundreds of thousands of dollars' worth of damage to the signal relay room in Riverwood.

He said the "badly damaged" signal box was a vital piece of equipment.

"It contains thousands of wires which control signalling in the area," he said.

"It is going to take us 48 hours to replace and rewire the signal box."

Mr Collins said the site of the signal box, which was installed in the mid-2000s, would be reviewed.

By 7:00am, some airport line services were running more than half an hour late.

Around 10:00am the train network experienced more delays on the T1 western lines due to an object being found on the track at Wentworthville and ongoing delays due to a signal equipment repair at Clyde.

Commuters on the line reported many of their morning trains into the city were cancelled entirely.

In a separate incident, a 4WD landed upside down on railway tracks in the Lake Macquarie area after it hit a fence last night.

The railway line was closed for an hour while the vehicle was removed.

Police charged the driver with high-range drink driving and said his licence had been suspended.

He is due to face Toronto Local Court next month.