Over the following decades, the freeway system was expanded to the north and south, greatly increasing the volume of traffic using the bridge.

[3] Preliminary planning for a bridge at the site finally began in 1947, but was suspended so that a replacement for The Causeway could be built at Heirisson Island, at the city's eastern end.

[7] The site also necessitated the reclamation of 60 acres (24 ha) of land from Mounts Bay for the bridge approach and interchange.

[15] Work on the bridge's precast concrete beams began in September 1957, and the first of these was lifted into place by the 60-foot (18 m) gantry crane in February 1958.

The last river pile was driven home in November 1958, and the final concrete beam was lowered into position in June 1959.

[11] However, Golden West was also the name for a popular soft drink;[16] the proposal encountered scorn from commentators and was quietly dropped.

[10] He unveiled a plaque on the bridge together with Premier David Brand, Commissioner of Main Roads J. Digby Leach and Works Minister Gerald Wild.

[10] The bridge formed part of the new Kwinana Freeway, which originally ran 2.4 miles (3.9 km) from the Narrows to Canning Highway.

[1] The prestressed concrete design was relatively new for Western Australia, where road bridges had traditionally been built from timber frameworks.

[12] The unusually soft soil conditions at the site forced the use of 160 "Gambia piles" for the bridge's foundations, named after the country in which they were first used.

[8] The hollow piles were driven by a drop hammer falling within them, then when they had sufficient resistance to driving, they were filled with reinforced concrete.

[18] Footpaths 8 feet (2.4 m) wide on either side of the bridge were formed by concrete cast in situ and cantilevered out from the adjacent beams.

[12] These footpaths were separated from the roadway and the bridge's edge by lightweight aluminium balustrades and safety fences installed by Bristile.

[25] The opening of the southern regions of Perth to easier CBD access changed the nature of the metropolitan area, prompting dramatic population growth south of the river.

Over the years, governments suggested various ideas to reduce the traffic using the bridge, including introducing congestion pricing similar to that used in Singapore, charging vehicles to enter the central business district during peak periods.

[7] By 1998, the original bridge was carrying 155,000 vehicles per day, with an average of 2,700 cars per lane between 7:30 am and 8:30 am, and was thought to be the busiest section of freeway in Australia.

[28] Alannah MacTiernan, then the Opposition transport spokesperson, attacked the plan, saying that the government should instead build a railway to Rockingham.

[31] Main Roads called for tenders for the bridge widening in July 1998,[32] and on 7 March 1999 it was announced that the building contract had been awarded to Leighton Contractors.

[47] After the Labor party won the 2001 state election, it reversed the previous government's position and started planning for the installation of railway tracks across the Narrows Bridge.

[49][50] The designers of "Package E" of the Southern Suburbs Railway (which included the Narrows Rail Bridge) were GHD, Coffey Geosciences and Wyche Consulting.

[53] The railway bridge deck was made from nine steel girders each weighing up to 99.5 tonnes (219,000 lb)[54] and up to 54 metres (177 ft) long.