M12 West – Environmental Outcomes

The M12 West package (M12W), between The Northern Road, Luddenham and approximately 250 metres east of Badgerys Creek, is part of the M12 Motorway, a key part of the Western Sydney Infrastructure Plan. The M12W project consists of a four-lane dual carriageway motorway with a central median for future six lanes.

The project was awarded an IS ‘Leading’ Design rating of 77 points, which exceeded the contract requirement of an IS ‘Excellent’ Design rating of 55 points. To achieve this rating, a variety of sustainability initiatives ranging from material reduction initiatives and indigenous and ecological design elements were integrated into the design. These initiatives include:

Glass Fibre Reinforced Polymer Reinforcement for Traffic Induction Loops
Every 400 metres along the alignment, a traffic loop will be implemented to count vehicles and their weight. The project implemented an Australian first innovation by replacing traditional steel reinforcement with Glass Fibre Reinforcement Polymer reinforcement in the vicinity of the traffic loops.

Extra Low Voltage ITS System
The project implemented an Australian first innovation by introducing Extra Low Voltage power supply for Variable Message Sign and Variable Speed Limit Sign equipment. The technology (BRAUMS VMS manufactured by Swarco) is powered by ELV technology with the next generation full coloured matrix lens, which eliminates the need for a transparent front screen utilised in standard VMS systems, and further optimises the focus of light toward the motorist for increased legibility.

Reduction in material impacts
The project achieved material impacts reductions through the following initiatives:
• Specification of a minimum 15% Recycled Asphalt Pavement, by mass, in all AC20 layers. This specification was included in drawings notes as part of the tender documentation.
• Reduction in width of mainline pavement design between concept design and detailed design phases. The shoulder pavement width was reduced from a 3-metre shoulder to a 2.5-metre shoulder on each side of the motorway.
• Reduction in Portland Cement content through replacement with 25% fly-ash in bridge and drainage structures, 40% fly-ash content in pavement subbase and 15% fly-ash in pavement base material.

Urban Design
The Urban Design Framework was developed to assist the implementation of an integrated and consistent urban design approach across the M12 Motorway. The urban design objectives established a series of strategic goals that the project must deliver, and several principles were developed to assist the realisation of these objectives. Key objectives and principles regarding Connection to Country and ecological value are:
• “Create a unique and distinct identity interpreting the rich sense of place” – principles include mindfulness of Connection to Country and Aboriginal perspectives on the landscape, and Aboriginal and European cultural interpretation.
• “Accentuate natural patterns” – principles include prioritising native species selection, maintaining water quality, preserving and enhancing waterways, and creating open spaces to facilitate ecological health within the project.

The engagement of Balarinji, an Indigenous design and strategy agency, meant Aboriginal heritage and culture were embedded in the earliest stages of the M12 Motorway design. This led to meaningful physical design initiatives that reflect Aboriginal heritage endemic to the project site.

Glass Fibre Reinforced Polymer Reinforcement for Traffic Induction Loops
When traditional steel reinforcement bars form an electrically conductive loop near a vehicle detection loop, the inductance change effect of the passing vehicle will be split between the reinforcement bars and vehicle detection loop. This reduces the sensitivity of the vehicle detector and can result in failure to detect a vehicle, or failure to classify vehicles correctly.

Implementing GFRP reinforcement as an alternative to traditional steel reinforcement has improved the accuracy of data collection. Additionally, this will lead to improved maintenance practices, which could potentially reduce the frequency of routine maintenance activities, reduce the material replacement costs and associated embodied carbon footprint as well as result in improved safety outcomes for road users.

Extra Low Voltage (ELV) ITS System
The BRAUMS VMS (manufactured by Swarco), powered by ELV technology with the next generation full colour matrix lens, significantly reduces energy consumption resulting in reduced operational energy demand and GHG emissions, and minimises the risk of electrocution and reduces the risk of fire in the event of a vehicle crash to the pole mounted ITS equipment. Carbon reductions of up to 70% for the Type B VMS systems and 67% for the Type C VMS systems can be achieved.

Material impact reductions
• RAP – this initiative goes beyond the RMS (now TfNSW) Sustainability Strategy “Minimum of 10% recycled content (when locally available) by volume in road base and sub base.”
• The specification of low carbon concrete mixes resulted in embodied carbon savings
• Bridge design optimisation resulting in reduction of bridge lengths
• Reducing the shoulder width by 1m overall, along the length of the project has saved approximately 5,720 m2 of pavement.

These initiatives implemented during detailed design demonstrated an 8% reduction in IS Enviropoints compared to the project Base Case. This reduction achieves level 1.53 for Mat-1.

Urban Design
The M12 Motorway project will create expansive public open space opportunities and establish links to future development and suburbs. Growth throughout Western Sydney around the new Western Sydney International Airport and Aerotropolis will mean a significant change to the landscape.

Balarinji was engaged by TfNSW to manage the Aboriginal cultural heritage design process that has been embedded into the M12West Motorway design. Balarinji in collaboration with the local Aboriginal community (including local artists) conducted research into the Aboriginal history of the M12 Motorway study area and tested and augmented this narrative through stakeholder and community consultation to develop an Aboriginal narrative and community endorsed design concepts to acknowledge local Aboriginal history and the Aboriginal community’s contemporary story. This includes:

• The development of a cohesive, overarching narrative of the Great Emu in the Sky which embodies the Aboriginal cultural identity of the site
• The placement of interpretive nodes to provide lookout points and rest areas for pedestrians and cyclists on the share user path
• Integration of Aboriginal art and patterns on bridges, retaining walls and noise walls that link into the principles of connection to country and narrative of the Darug people.
• Artistic wayfinding elements along the shared user path that provides information about key places and sites
• Utilisation of bridge components to frame and maximise long distance views.
Other key urban design initiatives, derived from the urban design framework, implemented on the project include:
• A pedestrian/cycle shared user path stretching the length of the motorway to connect existing and future communities
• Rehabilitation works to improve the biodiversity of the riparian corridors within the footprint of the project.
• Landscaping selection to introduce and reinforce the endemic vegetation communities of the Cumberland Plain and increase tree canopy cover in Western Sydney
• Combination of biodiversity offsets and onsite revegetation to support an overall enhancement of ecological value by 43% (Eco-1).

Australia First Innovations
The GFRP reinforcement for traffic induction loops and ELV ITS System improves safety outcomes for road users and results in carbon emission reductions. The data capture accuracy achieved through GFRP reinforcements will lead to improved maintenance practices, which could potentially reduce the frequency of routine maintenance activities, reduce the material replacement costs as well as result in improved safety outcomes for road users. Similarly, The ELV ITS System reduces operational energy demand and associated carbon reductions, whilst minimising the risk of electrocution and fire in the event of a vehicle crash to the pole mounted ITS equipment.

Indigenous design integration
The M12 Motorway Project will be a showcase project for the integration of Aboriginal design and art into public infrastructure. The M12 cultural narrative celebrates the traditional owners of the land and their culture, educates the local community that interact with the motorway either via vehicle or cyclists and pedestrians who use the shared user path and introduces foreign travellers to the rich Aboriginal culture of Australia as they leave the international airport and begin their time in Australia.

For example, the incorporation of the Six Seasons Planting within the landscape strengthens the overarching design narrative by highlighting and celebrating the unique flora and fauna cycles that characterise the six seasons of Western Sydney. This is featured within the Airport Interchange, at the interface with the Northern Road connection and at interpretive nodes positioned along the shared user path alignment. Overall, these initiatives educate users and the broader population, including international arrivals from WSIA, of the creation stories, dance, song, cultural practices, and iconography essential to the project’s identity.

Improved Ecological Value
To reinforce existing patterns of vegetation along the creek lines and floodplains, vegetation native to the area was used. These rehabilitation and revegetation works will improve the riparian health of the project site through improved water quality, reduce erosion, increased habitat, and improved connectivity between remnant vegetation surrounding the site. The combination of biodiversity offsets purchased on a ‘like for like’ basis to offset impacts of all vegetation (aquatic and terrestrial) required to be cleared and the additional onsite revegetation that will reintroduce endemic vegetation communities was calculated to result in 43% enhancement of ecological value when comparing pre and post development (Eco-1).

A lasting legacy of local Aboriginal history and contemporary culture is exhibited through the cultural narrative achieved in the following design elements:
• A sculpture portraying The Great Emu in the Sky, a well-known Aboriginal astronomical constellation, to preserve and enhance the Darug community’s culturally rich dreaming stories. This will be integrated into the centre of the interchange that connects the M12 Motorway into the Western Sydney International Airport.
• Integration of Aboriginal art and patterns on bridges, retaining walls and noise walls that link into the principles of Connection to Country and narrative of the Darug people.
• Interpretative Eucalyptus Canopy structures at rest stop nodes along the motorways shared user path that tie into the natural elements of the country.
• The use of emu footprint motifs that connect each of the proposed artworks and narratives along the motorway’s share user path leading to the Great Emu sculpture.
• Artistic wayfinding elements that provide information about the key places and sites.
M12W has contributed to the UN SDGs through the following initiatives:

9 – Industry, innovation and infrastructure
The M12 Motorway will provide direct access to Western Sydney International Airport at Badgerys Creek and connect with Sydney’s existing motorway network, providing increased road capacity, reduced congestion and travel times, and improved movement of freight.

The project applied two Australian first innovations in design. These were Glass Fibre Reinforced Polymer Reinforcement for Traffic Induction Loops and Extra Low Voltage ITS System. Both innovations have the potential to reduce the carbon footprint of the project and improves safety outcomes for road users.

11 – Sustainable Cities and Communities
A pedestrian/cycle shared user path stretching the length of the motorway will connect existing and future communities and encourage active transport.

The project reduced its carbon footprint by specifying the use of low carbon materials including:
• Specification of a minimum 15% RAP, by mass, in all AC20 layers.
• Reducing the width of mainline pavement design between concept design and detailed design phases by one metre.
• Bridge design optimisation
• Reduction in Portland Cement content through replacement with 25% fly-ash in bridge and drainage structures, 40% fly-ash content in pavement subbase and 15% fly-ash in pavement base material.

14 – Life Below Water
One of the key principles of the project was to reinforce existing patterns of vegetation along creek lines and floodplains to enhance ecological value as well as landscape character and motorway experience.
To offset the disturbance caused by the construction of the motorway, the riparian corridors were proposed for rehabilitation and revegetation with the P3 – Riparian Mix, a mix derived from plant species found within the Riparian Woodland vegetation community native to the area. The environmental benefits of this rehabilitation and revegetation include:
• Improved water quality
• Reduced erosion, loss of bank vegetation
• Increased habitat for both aquatic and terrestrial fauna/flora
• Reduced likelihood of weed establishment
• Improved connectivity (habitat links) between patches of surrounding remnant vegetation
• Plant species

15 – Life on Land
Avoiding and minimising impacts as far as possible was prioritised. Additionally, as outlined within the Urban Design Framework, connecting fragmented ecological communities was a key landscape principle of the project.
The onsite revegetation strategy aimed to protect, re-establish and reintroduce the endemic vegetation communities of the Cumberland Plain. Residual impacts that could not be avoided, minimised or mitigated were offset.
The combination of biodiversity offsets purchased on a ‘like for like’ basis to offset impacts of all vegetation required to be cleared and the additional onsite revegetation that will reintroduce endemic vegetation communities was calculated to result in 43% enhancement of ecological value when comparing pre and post development (Eco-1).