Key Facts
Southern Gateway Alliance (SGA) was formed in September 2006 to design, construct and deliver the Kwinana Freeway extension and Forrest Highway, one of Western Australia’s most significant infrastructure projects.
To meet this challenge, three of the industry’s leading companies - Leighton Contractors, WA Limestone and GHD came together with Main Roads Western Australia, our State road agency.
Construction commenced in December 2006 and the road was opened to traffic
on 20 September 2009. To achieve this timeframe, construction occurred concurrently
on several sections of the alignment.
Construction of the Kwinana Freeway extension and Forrest Highway included:
- 70.5 kilometres of dual carriageway
- 6 interchanges and 10 intersections
- 19 bridges
- 32 kilometres of principal shared path for pedestrians and cyclists
- 7 pedestrian underpasses at the Safety Bay Road, Karnup Road, Paganoni Road, future Mandurah Entrance Road, Lakes Road and Pinjarra Road interchanges
- 12 fauna underpasses
- More than 40 kilometres of fauna fencing
- the use of 5 borrow pits to source sand and limestone required for the project
- over 12 million tonnes of sand, 1.3 million of limestone and almost 1 million of crushed rock/gravel
- almost 27,000 cubic metres of concrete
- 821 piles and 146 beams for the bridges
- over 22 kilometres of drainage
- around 21 kilometres of noise walls.
The project team worked a total of approximately 3.8 million man hours without a lost time injury to construct the road.
At the project’s peak, the haulage operations involved a fleet of approximately 200 trucks, hauling some 50,000 tonnes per day and travelling a combined distance of 50,000 kilometres per day. There was also approximately 800 pieces of plant and machinery approved to operate on site.
To deliver the project, SGA awarded 375 contracts with 36 percent to local companies representing a $101 million injection into the local economy.