The Cumberland County Council was created in 1948 to prepare a town planning scheme to control and manage Sydney's future growth. With help from the Department of Main Roads, the County of Cumberland Planning Scheme provided a County Road reservation for a north-south at-grade urban arterial between Heathcote and Carlingford, along the present route. Appropriate reservations were gazetted in 1951 and the Department of Main Roads began acquiring land.

The first improvements to the route came not from the Department of Main Roads but from the Federal Government's ANSTO (Australian Nuclear Science and Technology Organisation) who made the decision in 1954 to build a nuclear reactor at Lucas Heights. In November 1955 a short deviation of 'New Illawarra Road' was completed, allowing work to begin on the research laboratories site. The Lucas Heights research laboratories were officially opened by Prime Minister Sir Robert Menzies on 18 April 1958.

Meanwhile, the Department of Main Roads was working on designs for a new bridge across the Parramatta River at Silverwater - the first to be constructed since the Ryde Bridge opened in December 1935. The four-lane pre-stressed concrete structure and northern approach road which connects with Victoria Road at Ermington was completed in November 1962. In my humble opinion the construction of a four-lane bridge was a big mistake, with Silverwater Road widening to six lanes in 1968. Now, a four-lane bridge separates two sections of six-lane road.

Other work completed prior to 1964 was the construction of Olympic Drive at Lidcombe - a new arterial road skirting the eastern edge of Watt Park and connecting to the railway underpass at Bridge Street. The name 'Olympic Drive' suggests it may have been constructed in the early 1950s, prior to the 1956 Melbourne Olympics. This new route provided a much needed alternative route across the railway line at Lidcombe and it superceded John Street as the main route when the Silverwater Bridge opened. Olympic Drive was gazetted as part of Main ROad No. 190 on 15 April 1955, however this probably followed actual construction by at least one year.

Also completed prior to 1964 was the establishment of a one-way street system in the vicinity of Bankstown Station, utilising parts of The Mall, Fetherstone St, Restwell St and Greenfield Pde.

The late sixties also saw the commencement of construction of a new bridge over the railway line, connecting Stacey Street North and Stacey Street South at Bankstown. The 295 foot long, six-lane wide concrete bridge replaced a footbridge over the railway line at the same location and was opened to traffic on 21 May 1970.

The coming of the 1980s saw an increase in works on the Metroad 6 corridor, which was inlcuded in the Department of Main Roads' Roads 2000 publication as the 'Silverwater Arterial' in 1987. The Silverwater Arterial shown in Roads 2000 stretched from the Pacific Hwy at Hornsby to the Princes Hwy at Heathcote, including a section of the now Cumberland Hwy. Projects proposed under the plan included the Silverwater Rd extension, a bypass at Lidcombe, widening and deviations at Bankstown and widening from Canterbury Rd south to Lucas Heights.

Duplication of Stewart Street at Dundas was completed in December 1980, along with the reconstruction of its junction with Kissing Point Road to favour east-west traffic. Just prior to this, Marsden Road was realigned between Stewart Street and Lawson Street to eliminate two tight corners in 1979.

Construction began on the Lidcombe Bypass in 1982 which encompassed widening Bede Street to six lanes and connecting it to Bridge Street at its northern end and Joseph Street at its southern end. The 'Bede Street Deviation' was opened to traffic in March 1986 but work was not fully completed until June 1988.

To connect between Stacey Street and Fairford Road, traffic had to dog-leg onto a short, narrow section of Canterbury Road. The first step towards providing a direct link between Stacey Street and Fairford Road came in 1983 with the completion of a six-lane deviation between Macauley Ave and Stacey Street South near Arkley Street. The next stage involved construction of a six-lane overpass (striped as four) across Canterbury Road. This overpass was opened in December 1986.

In July 1989 an overhaul of the legal classifications of the route was undertaken. Prior to this, large portions of the route were Secondary Roads - a classification which did not reflect its growing importance as a major through route. Subsequently the whole route from Ermington to Heathcote Rd was proclaimed Main Road No. 190.

At the southern end, the growing traffic volumes caused by rapid urbanisation of the Menai district were taking their toll on the Alfords Point Deviation. A tidal flow system was introduced to the bridge over the Georges River in February 1989, providing an extra lane for traffic in the direction of peak flow. Previously, the bridge had been operating with two lanes. The extension of Alfords Point Road south as a four-lane undivided, but grade-separated road from Old Illawarra Rd at Illawong to Menai Rd at Menai was completed in December 1992 and this included the widening of the the southern approach to the Alfords Point Bridge to four lanes. Provision has been made for future duplication of the Alfords Point Rd extension. Fairford Rd and Davies Road widening was also undertaken at this time and was completed by 1995.

For many years following the construction of Silverwater Bridge, Silverwater Road terminated at Victoria Road, Ermington. This situation was hardly ideal as there was no nearby north-south route for through traffic to connect to. However, there was a reservation preserved from the County of Cumberland Planning Scheme which provided for a grade-separated, limited access extension of Silverwater Road to Kissing Point Road and Stewart Street at Dundas. The decision was made to construct the extension as an at-grade, limited access road and a short section opened to traffic in January 1985 between Kissing Point Rd and Kingsford St. Progress ont eh project stalled until 1993 when construction of the overpass at Victoria Road was commenced. The extension of Silverwater Rd was completed and opened to traffic in January 1996. Upon opening of the Silverwater Road extension, State Route 45 was extended north from Ermington to Carlingford via Stewart Street and Marsden Road.

In early 1999 the last of the major deviations proposed in the Roads 2000 plan, the Stacey Street Deviation between Rookwood Rd and Hume Hwy at Bankstown, was opened to traffic. This eliminated a notorious dog-leg in the route and it was consequently rewarded with inclusion in the Sydney metroad system as Metroad 6. Its numbering as Metroad 6, a number which was not used in the original allocation of route numbers, suggests that the route was planned for inclusion originally but there was a need to wait until a few major works had been completed.

Following the opening of the Westlink M7 motorway, and the subsequent truncation of Metroad 7 at Beecroft, Metroad 6 was extended north along Pennant Hills Rd from Carlingford to Beecroft, now terminating at the M2 Motorway/Pennant Hills Rd interchange. Metroad 6 signage was installed in March 2006 after the Metroad 7 shields had earlier been covered with blacnk coverplates.

Recent Improvements

and the future