Prior to the COVID-19 pandemic, rapid growth in demand for rail transport lead to passenger crowding on major parts of the Sydney rail network. Demand for rail trips in Greater Sydney increased significantly from 300 million trips in 2015, to 420 million trips in 2018 — an average of 7.6% growth each year.

Previous forecasts predicted crowding during peak periods would have substantially impacted the reliability of the key lines by the mid-2020s.

Forecasts for future travel demand are now uncertain, though it is considered unlikely that peak hour capacity will be exceeded as soon as previously forecast.

A likely legacy of the pandemic is more flexible travel patterns, with more customers able to travel outside the traditional peak hour periods. Supporting this change is an opportunity to defer forecast peak hour crowding pressures  and increase public transport mode share across the day. However, increased travel demand outside of traditional peak hours brings into focus other challenges, especially where networks are shared between passenger and freight services.

In addition, signalling systems are  reaching the end of their effective life, with unsustainable maintenance costs and high risk of asset failures, which could lead to passenger and