Planning began for the Western Expressway in 1947, as the County of Cumberland Planning Scheme (CCPS) was being created. The CCPS identified a corridor from the City of Sydney at Glebe to the Gt Western Hwy at Lapstone, passing through Glebe, Haberfield, and Five Dock before joining the current route at Concord. This corridor was subsequently reserved in 1951.

Construction began in the late 1960's on the first stage, a 5km section of freeway from Russell St, Emu Plains to Bringelly Rd (now The Northern Rd), Orchard Hills. West of Mulgoa Rd, this section was constructed as single carriageway due to the high cost of bridging the Nepean River. The bridge and approaches would be duplicated when traffic volumes demanded. Access to this section was provided only at Russell St and Bringelly Rd. This section was opened to traffic in October 1971.
Construction of the next 14.5km stage, an easterly extension to Wallgrove Rd at Eastern Creek was undertaken simultaneously and opened to traffic in December 1972. Access to the freeway was provided only at Bringelly Rd, via a full diamond interchange, and at Wallgrove Rd, via a modified half-diamond which marked the temporary eastern terminus of the freeway.
Two years later, in April 1974, the freeway was extended to the Gt Western Hwy at Prospect. As part of this project, the temporary Wallgrove Rd terminus was reconstructed into a proper half-diamond. All trace of the freeway between the service centre and the Gt Western Hwy has now been removed.

Meanwhile, in April 1970, the Department of Main Roads announced that work would shortly commence on a four mile length of the freeway between Wentworth Rd, Homebush and Wentworth St, Clyde. The proposed section would require bridges at 11 sites to separate expressway traffic from all cross traffic, and would significantly relieve congestion on Parramatta Rd, which is saturated with heavy industrial traffic.

Closer to the City, the DMR was preparing plans for the length of the freeway from Ultimo to Concord. Heavy opposition greeted the Department, especially through Glebe, where it was feared the freeway would sever the neighbourhood into 3 parts and destroy the distinctive terraced streetscape. The anti-freeway protests eventually won out, with the NSW Government announcing, in February 1977, that it had decided to abandon major portions of planned inner-urban freeways. Particularly the F4 "...corridor reservation will be retained to a point east of Concord Rd in the vicinity of Loftus St, Concord, where connections to the existing road system can be developed. The present and planned construction west of this point would be developed progressively. The corridor reservation for the inner section of the freeway from the City to that point will be eliminated. The estimated cost of the roadworks proposed in the abandoned section would have been $287 million (1977)."1

Back at Homebush, a shortage of roadwork funds and the urgent need to complete the Warringah Freeway extension and the Bondi Junction Bypass caused the suspension of construction on the F4 in May 1977. Construction had already become a prolonged, drawn-out process due to protracted property resumption and utility adjustment negotiations. A major utility easement, containing up to ten different types of utilities, belonging to five different authorities, crosses the freeway route three times between Concord Rd and Wentworth St. Construction was recommenced in January 1979 and construction was also commenced on the section from Church St, Harris Park to Gt Western Hwy, Mays Hill.

In December 1982, the next stage of the F4, between Concord Rd, North Strathfield and and Melton St, Auburn, was opened to traffic. Access was provided at Concord Rd (via Sydney and Young Streets), east-facing ramps at Silverwater Rd, and a temporary connection to Parramatta Rd at Melton St.
Also opened in December 1982 was the section of freeway between Church St, Harris Park and Gt Western Hwy, Mays Hill. East facing ramps were provided at Burnett St, Merrylands and a westbound off-ramp at Coleman St.

Mid 1983 marked the commencement of the Granville Viaduct, the section of elevated freeway between James Ruse Dr and Church St. In September 1984, a 2.1km section of freeway opened to traffic, extending the freeway west from Melton St, Auburn to James Ruse Drive, Granville. The opening of this section was delayed by the complex construction of the viaduct across the Duck River, which was built on a curve and superelevation. Included in this stage was a temporary link to Parramatta Rd for NR32 traffic, via Martha and Harbord Streets. Also included in this stage was the construction of the west facing ramps at Silverwater Rd.

Following the permanent cancellation of a surface freeway east of Concord in February 1977, the DMR began investigating how to best integrate the prematurely truncated freeway into the existing road system. Major delayes existed to both north-south and east-west traffic in the vicinity of the Concord Rd terminus of the freeway, as it was not designed to be a permanent facility. In December 1985, the new improved connection to Parramatta Rd opened to traffic, 12 months ahead of schedule. This involved the reconstruction of SR33, which was operating as a one-way street system since the opening of the freeway in December 1982. Concord Rd and Leicester Ave now carry two-way traffic, while Sydney St functions as the eastbound off-ramp. The freeway mainline was constructed under the newly-aligned Concord Rd to meet Parramatta Rd where the old alignment of Concord Rd did. Westbound access to the freeway was provided from Parramatta Rd (east and westbound) and from Concord Rd (northbound). Meanwhile, plans to construct the freeway between Mays Hill and Prospect were halted due to a lack of available funding in 1985.

1986 was a busy year for the Western Freeway. Being one of the most important projects in the State Government's $5,000 million road building program, the Government boosted funding so that teh $38.6 million Granville Viaduct could be opened to traffic in April 1986. The 1.8km elevated section provides the greatest relief to traffic, bypassing a congested four-lane section of Parramatta Rd through Granville. As part of this project, ramps to and from the north side of James Ruse Dr were constructed at A'Becketts Creek. These ramps provide uninhibited traffic flow betweent he south and east legs of the Parramatta Ring Route. The ramps were opened to traffic in August 1987.

Meanwhile, residential development adjacent to freeway corridor near Penrith and St Marys had mate it necessary to provide additional entry and exit points as well as additional capacity across the Nepean River. In September 1983, the State Government announced the 5 year Blue Mtns Road Improvement Program, 1984-1989. The largest single proposal included in this program was the extension of the freeway as a 4-lane route from Mulgoa Rd to the Gt Western Hwy at Lapstone, including duplication of the Regentville Bridge across the Nepean River. In June 1986 a full diamond interchange was opened to traffic at Mulgoa Rd, followed in July by west-facing ramps at Mamre Rd and east-facing ramps at Roper Rd. In August 1986, the duplication of the Regentville Bridge over the Nepean River opened to traffic.

In December 1989, the two projects required to complete the freeway between Concord and Lapstone were commenced. The extension of the freeway from Russell St, west to the Gt Western Hwy in the vicinity of Governors Dr would bypass the narrow and winding section of the Gt Western Hwy, including the historic Knapsack Bridge. The other project, between Mays Hill and Prospect, would be constructed as a BOOT (Build-Own-Operate-Transfer) project. This meant that StateWideRoads, the consortium awarded the contract to build the the missing link, would construct and operate this section of motorway and to recoup the money spent, would legally be able to charge a toll for use of the road. To ensure that the lowest possible toll applied for the shortest possible time, the Government permitted SWR to toll the section between James Ruse Dr and Silverwater Rd, where significantly more traffic would pass through the booths than if they were located between Mays Hill and Prospect. As part of this project, SWR widened the freeway between James Ruse Dr and the newly constructed Homebush Bay Drive to 6 lanes. In May 1992 this widening and the missing link were opened to traffic. This also marked the change from freeway to motorway. Initially a $1.50 toll was charged for cars, ensuring that after the 20-year contract period, the motorway would be toll free.

In June 1992, east-facing ramps were opened to traffic at Wallgrove Rd, Eastern Creek, where previously only west facing ramps existed. The NR32 shield which had served the freeway for 20 years was replaced by the Metroad 4 shield in September 1992. A new interchange was also opened to traffic in November 1992, at the newly constructed Homebush Bay Dr/Centenary Dr corridor.

Meanwhile, construction of the westerly extension of the motorway was progressing. In June 1993, the new section of freeway between Emu Plains and Lapstone was opened to traffic, bypassing Knapsack Bridge. Now that the motorway was continuos between Concord and Lapstone, capacity issues were beginning to be addressed. Wisely, the freeway had been constructed in a reservation wide enough for ultimate widening to 8 lanes. The widening of the motorway was commenced in October 1996, with the first project, the widening of the Granville Viaduct, completed in 1998. During the year 2000, the toll charges rose twice, once in July from $1.50 to $1.60 due to the GST, and again in November to $2.20. The widening program was completed in 2001, providing 8-lanes between Church St and Coleman St and 6-lanes west to Mulgoa Rd. During preparations for the Sydney Olympics in the year 2000, west-facing ramps were constructed at Hill Rd, Homebush Bay, the provide access to the Olympic Park complex. These ramps were opened in mid-1999.