Metro Tunnel

The Metro Tunnel is a metropolitan heavy rail project currently under construction in Melbourne, Victoria, Australia. It includes the construction of twin 9-kilometre (5.6 mi) rail tunnels between South Kensington (north west of the Melbourne central business district) and South Yarra (in the south east) with five new underground stations. The tunnel will connect the Pakenham and Cranbourne lines with the Sunbury line, creating a new high-frequency cross-city line that bypasses Flinders Street station and the City Loop. The line is also planned to serve Melbourne Airport via a new branch line west of Sunshine.

The project will enable the operational separation of various existing lines on Melbourne's rail network and increase the capacity of the system to allow metro-style frequencies. The Metro Tunnel project includes the installation of high-capacity signalling and platform screen doors. With the delivery of other associated projects including accessibility upgrades, the introduction of High Capacity Metro Trains, and the removal of all level crossings across the Pakenham, Cranbourne and Sunbury lines, it will allow the corridor to run to rapid transit standards.

Known during planning as the Melbourne Metro Rail Project, the state government began planning the project in 2015. Initial construction works commenced in early 2017. Sections of the Melbourne central business district, including City Square and parts of Swanston Street, were closed to enable construction of the tunnel and stations. Tunnelling began in 2019 and was completed in 2021. The project was originally expected to be completed in 2026, but has now been brought forward to 2025. The project is being delivered by Rail Projects Victoria, formerly the Melbourne Metro Rail Authority, at an estimated cost of $9 to $11 billion.