The 40km Westlink M7 (previously known as the Western Sydney Orbital) is Australia’s biggest urban road project. The road was delivered as a Build / Own / Operate / Transfer (BOOT) scheme.

The WestLink consortium was selected to design, construct, maintain and operate the Westlink M7 for a total of 34 years, after which it will be transferred back to the Australian Government.

Westlink M7 Shared Path improvement works consisting of up to three separate stages was started in August 2010. The improvement works include drainage works, concrete works and asphalting of the existing 40km-long shared path that stretches from Prestons to Baulkham Hills. The project, which is being undertaken by Abigroup Leighton Joint Venture, is estimated to be completed within 12 months.

Construction timetable

The Deputy Prime Minister and Federal Minister for Transport, John Anderson, and the Premier of New South Wales (NSW), Bob Carr, officially launched the major construction work at West Hoxton on 7 July 2003.

At the end of 2003, construction activity occurred along most of the corridor. Key activities included:

  • Building temporary roads to access the Westlink M7 corridor
  • Building construction compounds
  • Removing existing structures
  • Relocating and upgrading utilities
  • Clearing, earthworks and installing drainage
  • Hauling fill material to sites using arterial roads
  • Constructing bridges
  • Constructing storm water detention basins

A number of associated roads were also upgraded as part of the project. The Westlink M7 opened to traffic on 15 December 2005, ahead of the previously expected completion date of 2007.

Transport infrastructure objectives

  • The construction corridor typically 100m wide, reducing to 65m in some areas – some interchanges required up to 320m
  • The route comprises four traffic lanes (two in each direction), a wide central median, shoulders, cuttings and embankments
  • Built to motorway standard, the Westlink M7 can provide safe travel at variable speeds of up to 110km/h
  • It has 18 interchanges
  • There are 38 overpasses and underpasses to maintain local access for pedestrians, cyclists and motorists
  • A 40km off-road shared cycle / pedestrian pathway traverses the motorway and connects with the Sydney Cycleway network

Bridges, noise barriers and road furniture

An urban and landscape design team developed a consistent identity for key Westlink M7 features included local road bridges over the Westlink M7, noise barriers on motorway bridges, road furniture and shared path features and lighting.

The same basic design was used for these elements along the length of the motorway to create a ‘linear identity’. For other features it was important to respond to the immediate environment, which varied along the Westlink M7 route. Key features tailored to the local environment include:

  • Motorway bridges as seen from the adjoining neighbourhood
  • Noise barriers, other than those on Westlink M7 bridges
  • Landscaping, including vegetation
  • Interchanges
“The 40km Westlink M7 is Australia’s biggest urban road project.”

The motorway links the M2, M4 and M5 motorways saving motorists significant amounts of time. It links the M5 at Prestons in the south with the M4 at Eastern Creek and the M2 at West Baulkham Hills in the north.

18 interchanges along the motorway provide access to the communities of Liverpool, Fairfield, Blacktown and Baulkham Hills, improving transport options to these areas.

Motorists on the Westlink M7 are now able avoid up to 48 sets of traffic lights on the trip from the M2 at Baulkham Hills to the M5 at Prestons.

The Light Horse interchange

The motorway boasts Australia’s largest interchange, where the Westlink M7 intersects with the M4 Western Motorway. This is the Light Horse Interchange (named after the Australian Light Horse that fought at Gallipoli in the First World War and had a training base at Walgrove Road – here the M7 crosses above the Walgrove bridge).

The Light Horse Interchange allows motorist access to the Westlink M7 from the M4 Motorway in all directions without having to stop at traffic lights. The interchange features three levels of on and off ramps allowing motorists to safely and easily travel between the two motorways.

  • There are 18 bridges in the interchange
  • The two main bridges are the Westlink M7 across the M4 – The northbound bridge is 431m long and the southbound bridge is 397m long
  • Eight ramps connect the Westlink M7 to the M4, all with electronic toll gantries, enabling motorists to access both motorways without the need to stop
  • 802 bridge segments were used in the interchange – each segment weighed between 40t–100t

The Light Horse Interchange was designed by Maunsell / Smec for the civil structural design and Conybeare Morrison / Context for the urban design and landscaping.

Electronic toll system

There are no toll booths on the Westlink M7. Instead, electronic tolling allows drivers to use the motorway without slowing or stopping to pay tolls.

Motorists can either get a tag for their car in advance or can arrange to pay for their trip via the e-pass system either in advance or within 48 hours of travelling. If they use the road without paying they will already have been photographed and will be fined.

Scanning equipment is mounted at points along the road corridor, either on special gantries over the roadway or, where possible, on existing or future overpass structures, allowing different toll levels to be charged depending on the length of the route used. The toll was set by a contract signed between Westlink and the NSW RTA in 2003.

“electronic tolling allows drivers to use the motorway without slowing or stopping to pay tolls.”

Other advantages of the electronic tolling include being able to charge different tolls for heavier vehicles, varying tolls depending on the time of day and integrating the road with the city’s existing motorway toll system.


The equity investors in the WestLink consortium are Transurban, Macquarie Infrastructure Group, Leighton Contractors (a subsidiary of HOCHTIF) and Abigroup Contractors.

A company comprising Abigroup Contractors and Leighton Contractors, Abigroup Leighton Joint Venture (ALJV), undertook design and construction of the Westlink M7. The Australian law firm Clayton Utz acted for the NSW Roads and Traffic Authority (RTA) throughout the negotiations.

The RTA coordinated the project’s development, environmental assessment and planning approval phases. During the implementation phases the RTA administered the project deed and ensured that the consortium delivered the Westlink M7 according to the agreed scope and approval conditions.

The project’s environmental impact statement went on public exhibition from 8 January to 5 March 2001. On 28 February 2002, the NSW Minister for Infrastructure and Planning approved the project.

In February 2003, the WestLink Motorway consortium entered an agreement with the RTA to finance, design, construct, operate and maintain the AU$1.5bn Westlink M7 motorway. The Federal Government contributed AU$356m towards the construction of this link, with the remainder of the cost being met by the private sector.

The WestLink consortium was given the ‘Project Finance Deal of the Year’ award by Australia’s ‘CFO’ magazine in July 2003.