A new report reveals $7.3 billion is needed to upgrade Wellington's rail network so the region's growing population isn't packed onto trains like sardines.
The fragility of the rail network was on full display earlier this week when a signal fault led to widespread cancellations, including all services on the Melling line.
The problem was fixed only after an expert was flown in from Auckland, who worked through the night.
Coincidentally, just days after the incident, Greater Wellington Regional Council released a report outlining how much more money will be required over the next 30 years to future-proof the network.
Wellington Regional climate change targets are also looming, such as reducing carbon emissions by 35 per cent by 2030.