Alignment

The first main road west from Sydney was Great Western Highway, shown above in orange. The County of Cumberland planning scheme provided for a modified route west, much of which was later built as M4 Western Motorway. With the opening of the M4 East Tunnel and Rozelle Interchange in 2019 and 2023 respectively, the M4 today extends as far east as the Anzac Bridge.

Western Freeway

M4 Motorway looking East from the Olympic Park line

M4 Tunnel entrance at North Strathfield looking east

Western Freeway was originally constructed in several stages between the late 1960s and the mid-1980s: the first 5km-long section between Emu Plains and Regentville (including a new single carriageway bridge over the Nepean River, duplicated in 1986) opened in October 1971; the second 14.5km-long section between Regentville and Eastern Creek opened in December 1972; the third 4km-long section between Eastern Creek and Prospect opened in April 1974.^[14] On the basis of a pre-election promise made by the NSW Premier Neville Wran in 1976, all land reserved for the expressway between Pyrmont and the (then) eastern termination point at Strathfield was sold off to property developers or declassified as a freeway corridor in 1977 by the State Government.^[15][16] Separate sections of Western Freeway, from Great Western Highway in Mays Hill to Church Street and Woodville Road in Parramatta, and from Auburn to Great Western Highway at Strathfield, were opened on 16 December 1982 by Premier Wran.^[14][17] In September 1984, a 2.1km section of freeway opened to traffic, extending the freeway west from Auburn to James Ruse Drive in Granville. The 1.8km Granville Viaduct project opened to traffic in April 1986, the elevated section finally connecting the Granville end to the next section at Parramatta and allowing both Granville and Parramatta to be properly bypassed. As part of this project, ramps to and from the north side of James Ruse Drive were opened to traffic in August 1987.

Western Motorway

A lack of funding resulted in the Wran Labor government halting plans to construct the final stage of the freeway between Mays Hill and Prospect in 1985. In December 1989 work to construct this stage began as a Build-Own-Operate-Transfer project.^[18] In return for funding construction StateWide Roads, the consortium awarded to build the stage, was given permission to toll the section between James Ruse Drive and Silverwater Road as traffic volumes on this section were significantly higher than between Mays Hill-Prospect and would allow a shorter toll period with lower tolls. The consortium would also widen the section between James Ruse Drive and the newly constructed Homebush Bay Drive to six lanes. The Mays Hill to Prospect section opened in May 1992 and an initial of a $1.50 toll was implemented; as a consequence of the toll, the freeway also changed names to Western Motorway. The concession held by StateWide Roads ended on 15 February 2010, with operation of the motorway returned to the Roads and Traffic Authority and the toll removed. At the time, StateWide Roads was owned by Transurban (50.6%) and Utilities Trust of Australia (21.5%).^[19]

The motorway is mostly three or four lanes wide in either direction, and carries constant heavy traffic during daylight hours, seven days a week. Built as a four-lane motorway, it was widened to six lanes during 1998 to 2000, but this did little to ease the congestion.

Originally planned in the mid-1950s to start in the Sydney central business district,^[20] the eastern section was built only as far west as Pyrmont, as part of the North West Expressway (or F3), a freeway that would connect the Sydney and Newcastle central business districts; this section is now part of the Western Distributor. From there it was to have joined with the Western Expressway (the F4), and the Southern Expressway (the F6) in Glebe.^[21] The western end of Western Freeway was to be routed through the Mitchell's Pass area through to Blaxland, however due to protests and the fact that the historic Lennox Bridge was very close to the intended pathway, it was decided to terminate the road at Russell Street, Emu Plains until a solution could be later found. This would have bypassed the Lapstone Hill area and avoided the sharp bends as the road enters Glenbrook. In December 1989 the western extension of the freeway commenced construction, from Russell Street to Great Western Highway in the vicinity of Governors Drive in Lapstone, would bypass the narrow and winding section of Great Western Highway, including the historic Knapsack Bridge; in June 1993, this new section was opened to traffic.^[22]

The passing of the Main Roads Act of 1924^[23] through the Parliament of New South Wales provided for the declaration of Main Roads, roads partially funded by the State government through the Main Roads Board (later the Department of Main Roads, and eventually Transport for NSW). With the subsequent passing of the Main Roads (Amendment) Act of 1929^[24] to provide for additional declarations of State Highways and Trunk Roads, the Department of Main Roads (having succeeded the MRB in 1932) declared Western Freeway as a motorway (under plan number 6004), on 9 February 1977,^[2] and was re-declared to cover each extension until it reached its eastern terminus in Concord; the tollway today still retains this declaration (under Tollway 6004).^[25]

In 2013, the state government announced the intention to implement a 'Managed Motorway' scheme on the M4 over the coming years to improve traffic flow. Mechanisms to be used include improved Variable Message Signs, Ramp metering signals, dynamic speed and incident management, and an upgrade of the Emergency Telephone System.^[26]

National Route 32 was allocated to Great Western Highway originally in 1955: as new sections of the freeway opened, National Route 32 was re-routed along these new sections; from 1974, sections of the highway formerly allocated National Route 32 were allocated State Route 44 instead. Freeway Routes were introduced in 1973, and Freeway Route F4 was allocated to all existing sections, and extended along with National Route 32 each time a new section was opened. In 1992, at the same time the freeway was renamed, Metroad 4 replaced both National Route 32 and Freeway Route F4 across the entire freeway from Emu Plains to North Strathfield. With the conversion to the newer alphanumeric system in 2013, Metroad 4 was replaced with route M4.^[27]

The section between Church Street in Parramatta and the eastern end at Concord was widened as part of WestConnex works. Construction commenced in March 2015 and in November 2015, it was announced that toll points would be reinstated on this section from 2017 to cover costs of the WestConnex project. The toll was introduced on 15 August 2017.^[6]

M4 East

WestConnex M4 East Tunnel

WestConnex M4 Tunnel western exit at Homebush
Overview
Route	M4 Motorway
Start	Haberfield (east)
End	Homebush (west)
Operation
Work begun	2015
Constructed	Leighton Contractors Samsung John Holland Group
Opened	13 July 2019 (2019-07-13)
Owner	WestConnex
Operator	Sydney Motorway Corporation
Toll	$4.41 (2020 dollars, subject to indexing, each way)
Technical
Length	5.6 kilometres (3.5 mi)
No. of lanes	3 in each direction
Operating speed	80 kilometres per hour (50 mph) (variable speed limit)

Up until 2019, the eastern end of the M4 was at North Strathfield, some 15 kilometres (9.3 mi) from the Sydney central business district. Over the years a number of proposals were made to extend the M4 east towards the city. One plan in the 1990s involved extending the M4 eastwards by approximately 5 kilometres (3.1 mi) so that it would subsequently end in Ashfield and be continuous with the City West Link. Further planned upgrades to the City West Link would mean commuters going west out of the city could get to Parramatta without passing through traffic lights.

The government proposed a subsequent $7 billion plan for M4 East in July 2002, including three options:^[28][29]

• short tunnel option: a 3.6-kilometre (2.2 mi) tunnel between the M4 at Concord and City West Link and Parramatta Road at Haberfield
• long tunnel option: a 6.5-kilometre (4.0 mi) tunnel between the M4 at Concord and City West Link at Lilyfield
• slot option: a sunken trench road similar to the Eastern Distributor, between the M4 at Concord and Parramatta Road at Haberfield

All three options would run below or parallel to Parramatta Road and/or City West Link. The short tunnel option was preferred for having lower costs both during construction and operation. The long tunnel option was considered to have the potential to increase congestion on the approaches to Anzac Bridge, causing eastbound queues to extend into the tunnels. The slot option could be constructed at a similar cost to the short tunnel, however, it was considered to not provide the same level of traffic benefits as the short tunnel option. Additionally, the option would need to acquire additional properties and the construction period for this option would be longer.^[29]

Between 2003 and 2004, the preferred short tunnel option for an eastern extension of the M4 Motorway was exhibited.^[29] Members of the government were divided over the M4 East proposal and ultimately did not proceed with it in early 2005 due to community opposition.^[28][30] The preferred option eventually formed the basis of the concept design for the M4 East project of the WestConnex.

In the month prior to the 2011 state election, the NRMA released a report in which it recommended building a tunnel to connect the end of the M4 at Concord and the start of the City West Link, relieving Parramatta Road of enough traffic to convert it into two lanes for slower-moving local traffic, two lanes of light rail and a cycleway.^[31] The report argued that this would allow Parramatta Road to be transformed with medium-density housing, shops and cafes and that the $10.04 billion in additional stamp duty and other revenues from this would pay for the $7.38 billion price tag of the project.^[32]

In October 2012, the NSW Government announced their commitment to deliver the WestConnex project, involving widening the existing M4 motorway as well as extending it east with a tunnel from North Strathfield to Taverners Hill. The project also involved duplicating the M5 East tunnel and building a new tunnel linking the M4 and M5 motorways.^[33]

In June 2015, the tender to design and build the WestConnex M4 Tunnel was awarded to Leighton Contractors, Samsung and John Holland.^[34] Located 35 metres (115 ft) beneath Parramatta Road, the 5.5-kilometre (3 mi) dual-tunnel was funded through a $1.8 billion grant from the NSW Government and, from the Australian Government, a $1.5 billion grant and concessional loan of up to $2 billion, plus user tolling.^[35] The M4 East opened to traffic on 13 July 2019^[8][9] and tolls were levied on both the M4 East Tunnel ($4.41 in 2020,^[36] comprising a flagfall and a change per distance travelled, subject to indexing) and the widening of the M4 between Parramatta and Homebush (base of $4.21 each way, subject to indexing). Both tolls will continue until 2060.^[37][38]

M4 & M8 Extensions

Stage 3 of the WestConnex scheme saw a new motorway connection running from the end of the M4 at Haberfield to connect with the airport and the M8 Motorway (formerly the New M5) at St Peters, along with an interchange at Rozelle linking to the Anzac Bridge and Victoria Road (Iron Cove Bridge). This section aimed to reduce travel times between Western Sydney and Port Botany while removing heavy vehicles from surface streets in the Inner West.^[39][40]

In September 2022, the government announced that the connection would be referred to as extensions of the M4 and M8 when the connection opened.^[10] The main tunnels between WestConnex M4 Tunnels at Haberfield and the M8 Tunnels at St Peters opened on 20 January 2023, with the M4 and M8 route markers extended to meet at Leichhardt until Rozelle Interchange opened.^[11] The interchange opened on 26 November 2023 and the M4 route marker was further extended to Rozelle and Anzac Bridge where the route transitions into A4.^[13]

M4 Smart Motorway Project

In July 2019, the NSW government announced its M4 Smart Motorway Project^[41] which involves widening the on and off ramps for the untolled section of the motorway between Lapstone and Mays Hill, including the installation of overhead gantries with variable speed limit displays and traffic signals on the on-ramps between Orchard Hills and Mays Hill for traffic metering during peak periods.