The West Gate freeway linking Geelong to Melbourne CBD (Central Business District) was built in 1971. The freeway upgrade project was initiated in 2007 and completed in late 2010. It was aimed at improving the driver safety and reducing congestion and travel times. The project was managed by Vic Roads.

The freeway is used by more than 160,000 vehicles a day.

West Gate project

The West Gate freeway upgrade was part of the $1.39bn Monash-CityLink-West Gate (M1) upgrade of the M1 corridor. The project involved widening the freeway, access ramps reconfiguration, bridgeworks and reconstruction of existing traffic lanes.

It also included extending the 5.6km road between the CityLink Tunnels and the West Gate Bridge. More than 77,394t of asphalt, 64,364t of concrete, 11,311t of steel, 5,513m of pipe and 87,000m³ of contaminated material was reused for the project construction.

The upgrade has improved the average speed on the West Gate freeway by 20km an hour in westbound directions and 10km an hour in eastbound directions during peak traffic periods. It also improved access for high occupancy vehicles, which supports the future expansion at Melbourne port.

Contractors involved in the West Gate freeway project

“The freeway upgrade project was initiated in 2007 and completed in late 2010.”

The $605m design and construction contract for the West Gate freeway upgrade was awarded to the West Gate Freeway Alliance, which is comprised of Thiess Contractors, Vic Roads, Baulderstone Hornibrook, Parsons Brinkerhoff and Hyder Consulting.

The alliance engaged SMEC to provide proof engineering services for the project. SMEC’s scope of work included checking all the new structures for strength, stability and safety during the construction. Hyder Consulting provided the design services for the upgrade project.

ARC manufactured and supplied the steel reinforcement for the structures. It supplied more than 1,170t of high tolerance reinforcing steel bars and more than 3,000t of cut and bent reinforcing steel. It supplied 700t of reinforcing steel to Westkon Precast, who later cast and delivered it as bridge beams.

Rhino Water Tanks installed water tanks of various sizes for capturing rain water from the Bolte Bridge road. The water was used for dust suppression and other purposes during construction.

The alliance won the Australian Construction Achievement Award for the upgrade project in 2011.

Construction of the freeway upgrade project

Geo-technical investigations on the upgrade were commenced in late 2007. The construction works began in May 2008 and were completed in March 2010, four months earlier than the scheduled completion time.

The works included a new viaduct for westbound traffic, a new entry ramp for the access of CityLink tunnels and a new eastbound ramp at Bolte Bridge, westbound ramp at Montague Street and an eastbound exit-ramp for drivers from West Gate Bridge. They also included intersection works at Power Street Todd road, Lorimer Street, Kings Way, Kavanagh Street and Queens Bridge Street.

The bridge deck between Montague Street and Kings Way, the carriageways on Montague Street and West Gate Bridge and the freeway bridge deck at Kings Way were widened. Seven traffic signals were installed at various intersections.

The construction also included replacing 12 expansion joints and 200 lighting poles, installing a new emergency access gate service, reconfiguring Montague Street westbound entry-ramp and realigning Lorimer Street and Cook Street.

“The freeway is used by more than 160,000 vehicles a day.”

The interchange at Montague Street, Todd Road entry-ramp and cyclist and pedestrian facilities were upgraded. The old drainage system was replaced by a new slim line drainage system. The eastbound entry-ramp at Montague Street was demolished and realigned, 30 new signage gantries were erected and the eastbound entry ramp at Cook Street was relocated.

The freeway between West Gate Bridge and CityLink Tunnels was re-asphalted and service locations such as sewers, gas and water mains, high voltage power and optical fibre were replaced.

Traffic management system

The traffic team of the alliance worked in association with the stakeholder and delivery teams for traffic management to carry out coordinated construction works.