KiwiRail has not taken a number of reasonable measures to reduce the risk of train collision at Wellington Railway Station, according to a report from the Transport Accident Investigation Commission (TAIC).
It is the second time TAIC has warned about a heightened risk of commuter trains crashing at the station because of congestion.
It follows an investigation into an incident in 2017, where two trains narrowly missed colliding after a driver failed to see a red light as he tried to return to the Wellington Railway Station to get his brakes checked.
The commission found there was limited space at Wellington Railway Station, which had heighted congestion and risk of trains colliding.
The small space had also resulted in a lack of fail-safe back-up systems if a driver failed to stop at a red light.
"Any increases in commuter train services into and out of Wellington through this tight track layout will increase the pressure on this bottleneck area, and in turn increase the underlying risk of relying on train drivers to stop at red lights," said the report.
It noted that several recommendations to improve safety were made to KiwiRail and the Greater Wellington Regional Council in December 2017.
"On 15 December 2017 the Commission recommended that the chief executive of KiwiRail liaise with Greater Wellington Regional Council to develop a long-term strategy for the metropolitan rail system, with a view to identifying and addressing the current safety issues with the track and signalling infrastructure in the Wellington Station area."
But the report said several of those, including better communication between drivers and those controlling the trains had not been implemented.
"This incident has shown that more work is required of KiwiRail to further reduce the likelihood of trains colliding within the Wellington Station area."
KiwiRail acting chief operations officer Henare Clarke said in a statement the company had implemented some changes to improve safety.
"A review was carried out to identify any similar locations in the Wellington Metro Area and as a result train stops at Petone were relocated. Train stops mechanically activate the brakes on a train if it passes a signal that is set at stop."
Mr Clarke said a joint Wellington Network Risk Forum was also established in May 2018, to identify any further concerns.
"The forum has representatives from GWRC, Transdev, and KiwiRail. In addition a joint health and safety governance committee, which includes union involvement is also looking at this issue as part of its scrutiny of all health and safety matters," he said.
"An independent report on the conflicting route risks around the Wellington Station Approaches was received in early September and is being considered with regard to a plan for the provision of a modern Automatic Train Protection (ATP) System, similar to the system used on the Auckland Metro Network, along with other risk mitigations. "
But Mr Clarke said he was satisfied that overall safety procedures around the Wellington station were robust.