Armadale, Midland and Fremantle rail lines capacity

Infrastructure Australia | Infrastructure Priority List |

Armadale, Midland and Fremantle rail lines capacity

icon stage 1
icon stage 1 red
icon stage 2
icon stage 2 red
icon stage 3
icon stage 3 red
icon stage
icon stage red
icon stage 4
icon stage 4 red

Armadale, Midland and Fremantle rail lines capacity

A graphic of the Australian continent with WA state shaded and small dot representing Perth.
Perth, WA
Fast-growing cities
Efficient urban transport networks
WA Government
Near term (0-5 years)
26 February 2021
Armadale, Midland and Fremantle rail lines capacity

The Armadale, Midland and Fremantle rail lines are known as Perth’s ‘heritage lines’. They were built in the 19th Century and service well-established suburbs around Perth. These lines experience significant peak- period demand, which is expected to grow as they serve areas with considerable infill targets.

Perth’s passenger-rail network accommodated 62 million trips in 2019 and is a key access mode for commuters to and from Perth city.

The capacity of the Armadale, Midland and Fremantle lines is insufficient to accommodate future growth. This will lead to crowding, passenger discomfort, unreliability and road congestion if people choose not to travel by rail.

Much of the signalling, rolling stock and station assets on the heritage lines are nearing obsolescence. This creates challenges in managing and operating the network and interface between the heritage lines and the newer Joondalup and Mandurah lines.

The 2019 Australian Infrastructure Audit found that densification in our largest cities is placing pressure on legacy networks like Perth’s heritage lines.

Potential investment options

The Western Australian Government has considered a range of options to address the problems. These include options involving operational changes, infrastructure upgrades, and packages combining both types of interventions. Options were assessed through multi-criteria analysis and cost-benefit analysis.

The Western Australian Government recommends that a series of platform extensions and signalling upgrades is made across the Midland, Fremantle and Armadale lines. These upgrades are intended to be implemented through a program of works, referred to as the Platform and Signalling Upgrade Program.

We consider the shortlisted options to be suitable for further detailed assessment, with development of detailed business cases to support investment decisions.

Strategic Fit

The program supports the decision of the Western Australian Government to invest in new rolling stock as the existing fleet reaches end of life. Specifically, upgrades on the heritage lines will allow for platforms to accommodate an increase from four-car trains to six-car trains.

The program also aligns with investment by the Western Australian Government and Australian Government in other programs focused on improvements to Perth’s rail network. This includes METRONET projects and the High-Capacity Signalling (HCS) program. It will be important to understand how any changes to delivery timing of the HCS program may impact this program, given both involve signalling upgrades.

There is also strong alignment to themes of the Australian Government’s Infrastructure Policy Statement, including productivity, equity and connectivity, as well as safety.

Societal Impact

The program is expected to deliver benefits to public transport users by reducing travel time and crowding in train carriages, as well as improving travel reliability. The program will also benefit road users who may experience less congestion.

The program is also expected to achieve sustainability benefits, by reducing private vehicle travel and the associated emissions.


The program is planned to be delivered over 14-years through a sequence of eight packages. This is so infrastructure upgrades align with expected patronage growth over time. Packaging of the program will also minimize disruption to rail services and reduce market delivery risks.

The Public Transport Authority is investigating staging the delivery of individual packages, including the implementation of operational changes and infrastructure upgrades, taking into consideration land use around stations and forecast patronage levels.

Next Steps

The proponent is currently progressing planning for individual packages. For packages where more than $250 million in Australian Government funding is sought, the proponent will submit a business case (Stage 3 of Infrastructure Australia’s Assessment Framework) to inform a funding decision.


Refer to Infrastructure Glossary for terms and definitions.