A piece of paper was the only notice given to a train driver that he should slow down before his train derailed north of Melbourne, killing himself and another man.
The NSW Trainlink XPT passenger train was on its way to Melbourne from Sydney on February 20, 2020, when it came off the tracks at Wallan soon after 7.30pm.
Experienced driver John Kennedy, 54, and 49-year-old rail worker Sam Meintanis were killed, eight passengers were seriously hurt and another 58 people sustained minor injuries.
The Australian Transport Safety Bureau's final report into the crash was released made 37 findings including in relation to 15 safety issues.
On the day of the derailment, the train was diverted through the Wallan loop track because the signalling system was down on the normal route's straight section of track.
Instead of entering the loop section at the required 15km/h, the passenger train was travelling at speeds of between 114km/h and 127km/h.
"We know the emergency brakes were applied some 150 metres or so before the turnout," ATSB chief commissioner Angus Mitchell said on Wednesday.
"But that wasn't sufficient to wipe off the speed that was required to navigate that turn."
There was no evidence to suggest the driver was incapacitated or there was a track defect that led to the derailment, the report found.
Instead, it was likely the driver was not aware there was a change of route and he expected to travel through the straight section where the speed limit was 130km/h.
He had been through the straight section of track eight times in the 12 days before the derailment but he had never been diverted through the Wallan loop.
The driver was given a piece of paper advising him of the new route but there was no process in place that required him to confirm with network control he understood the changes.
"There was no system in place to mitigate either a misreading or any other human interaction," Mr Mitchell said.
"A safety system needs to be multi-layered in its defences and it cannot rely on any one piece of technology or one human to be the only defence."
Two V/Line services had successfully made their way through the Wallan loop in the hours before the XPT passenger train derailed.
V/Line were notified of the changes the night before and they briefed their crews but NSW Trains did not follow a similar procedure, Mr Mitchell said.
"We know that the V/Line system did have greater checks and balances in place," he said.
The bureau found there was too much reliance on administrative controls and the rail industry should instead modernise its safety systems through existing and emerging technology.
NSW Trains has been contacted for comment.