Thinking ahead to deliver lasting benefits
Designing for the future
Design plays a critical role in how sustainable a completed and operational road, tunnel or bridge is. During the design phase, decisions are made on materials used during construction, road geometrics, ventilation and lighting solutions and maintenance access routes. All these factors contribute to a road’s overall sustainability.
We work with our government partners, residents, businesses, and community groups to develop design solutions that meet both local needs and long-term city visions. We also collaborate with neighbouring communities to create new open spaces, improve active transport connections and protect local ecologies.
Our approach ensures our new roads deliver lasting benefits beyond safer and more efficient road travel.
Reducing emissions by design
Smart road and tunnel design can help reduce vehicle emissions
Factors such as the gradient or steepness of the motorway, its alignment and the smoothness of the road’s surface (pavement) can go a long way toward reducing vehicle emissions. All of these elements can help vehicles travel at a consistent speed and with less of the stop-start driving that increases vehicle emissions.
Collectively, in FY22, our customers saved:
total travel time saved on average each workday, compared to alternative stop-start routes
in GHG emissions (on average)
Average fuel saved each workday
Rolling on through
How smarter tunnel gradient design improves your travel
Many older tunnels were built with a significant slope, where motorists effectively drive downhill as they enter a tunnel and then uphill as they exit. An example of this is CityLink’s Burnley Tunnel in Melbourne. This tunnel is much steeper and deeper than it seems. Drivers descend around 65 metres below the Yarra River, then back up again as they exit. It’s kind of like driving on the West Gate Bridge, but upside down (and with no resident demogorgons).
When motorists drive through sloping tunnels, it’s easy to miss visual cues indicating it’s time to accelerate for the climb back out. This can cause congestion—if motorists don’t accelerate in time, their vehicle will slow, and all vehicles behind must slow in turn. Steeper gradients also mean motorists must brake and accelerate inside the tunnel as they adjust their speed, reducing fuel efficiency and increasing emissions.
Building efficient travel into our tunnel design
We’ve designed many of our newer tunnels (NorthConnex in Sydney and the West Gate Tunnel in Melbourne included) with flatter gradients. This removes the need for significant braking or accelerating inside the tunnel—motorists can cruise on through at a relatively steady pace. We’ve also made these tunnels wider and brighter (even installing innovative lighting effects on NorthConnex) to make it easier for motorists to read the road ahead and adjust their speed accordingly.
Plus, we’re now transforming the Burnley Tunnel into a brighter, more open-looking tunnel that will feature pace-maker lighting—an Australian first—designed to give drivers visual cues for maintaining consistent speeds, helping improve both congestion and safety.
Major projects using less materials
Multiple Transurban projects have been rated as Australian industry leaders for their sustainable design or construction. These ratings considered multiple sustainability factors, including how our design solutions minimised use of new materials.
Materials used in construction are often produced via greenhouse-gas-heavy processes, with associated emissions known as embodied emissions. Reducing the use of concrete, asphalt and aggregate reduces embodied emissions, and also reduces the amount of trucks required to deliver these materials to our construction sites.
Combined emissions and materials reductions we achieved across our Australian IS-rated projects are shown here.
Futureproofing a critical transport connection
In Australia and North America, we’ve already seen the damage extreme weather can do—even to large-scale infrastructure such as roads. As the impacts of climate change continue to increase, we need to ensure our roads and tunnels can withstand events such as extreme heat and flooding.
Our roads and tunnels provide essential connections between communities and services, and they are also critical routes for emergency services—so futureproofing them now is vital.
Our M4–M5 Link project (new tunnels connecting WestConnex M4 with the M8 in Sydney) has been designed and constructed to effectively withstand projected climate change impacts during its ongoing, long-term operations.
To ensure our mitigation measures are effective and that our assets will demonstrate resilience into the future, we are assessing climate-related risks (threats and opportunities) across our markets using physical climate science projections.
In Sydney, this includes projections of hotter, drier and more extreme weather conditions, and higher global sea-levels.
We’ve built resilience into the M4–M5 Link project by aligning our design solutions with projected future climate impacts and scenarios. Examples include:
The tunnels’ drainage, portals, pavement design and ancillary surface facilities have been designed and built to withstand projected extreme rainfall and flooding events.
Flood mitigation features built into the tunnels are sized to safely handle projected volumes of water. We’ve also installed back-up power to support the tunnels’ deluge management equipment.
Heatwaves and high-temperature events
Materials used in the tunnels are extremely durable to ensure they withstand projected high temperatures. Heat events put strain on a city’s overall power supply. To ensure safe tunnel operations, backup power and battery systems have been installed in the tunnels to maintain ongoing supply. For example, we have installed uninterrupted power systems (UPS) at each substation. The UPS will also power emergency lighting and signage in the tunnels.
Getting creative with construction materials
How design innovation delivers sustainable solutions
The CityLink Tulla Widening (CTW) project (Melbourne) added extra lanes to the Tullamarine Freeway between the Bolte Bridge and Melbourne Airport. We delivered the widening works on the tolled, CityLink section (Bulla Road—Power Street) of this project.
During the design phase, we worked with our contractors to find ways to reduce our works’ environmental impacts. This meant looking at the materials used to build the roads, material quantities needed and where the materials came from. Our works included building more than 30 kilometres of new traffic lanes—requiring huge amounts of road-construction materials. Given, for example, 8% of global GHG emissions come from cement production, reducing material use wherever possible made sense. Our design and construction improvements included:
Using more than 3,000 tonnes of recycled asphalt and 120,000 tonnes of recycled concrete
Using hybrid batteries and generator systems to power temporary remote work sites
Using 25% recycled water, reducing potable water requirements
Diverting more than 280,000 tonnes of waste from landfill
Our section of the CTW project was completed in 2017. All remaining works were completed in 2019—and the extra lanes are now helping motorists save up to 17 minutes’ travel time between bridge and airport, including travel on the tolled CityLink section of this journey.
Building better transport
From city-wide to local streets
The roads we build provide vital links between industries and transport hubs, between people and jobs and between friends and families. But we don’t stop with roads. We also build walking and cycling routes and new parks, install new artworks and protect important natural, cultural and heritage areas—working with those who live nearby to ensure our solutions meet local needs.
Safe passage for local wildlife
Logan Enhancement Project
with vital habitat
One bridge crossing a Queensland road is designed, not for vehicles, bikes or human pedestrians, but for local wildlife. And fittingly, the bridge isn’t paved with asphalt or concrete. Instead, it’s been topped with soil and planted with hundreds of native trees and shrubs. The crossing means animals can cross the road safely when journeying between the nearby Parkinson Bushland and Karawatha Forest—ensuring they can get where they want to go for food and shelter, and helping them find each other when it’s breeding season.
guided our approach
The fauna crossing was built as part of our Logan Enhancement Project, south of Brisbane, that widened sections of the Logan and Gateway Extension motorways, improved intersections and added new access ramps. The crossing was built using a BEBO arch—the second of its kind in Queensland. More than 200 species of wildlife live in the area and the crossing was created in consultation with the local community, concerned about wildlife safety. This crossing helps wildlife’s essential habitat remains a safe domain.
More ways for
animals to get around
Our cameras spotted wallabies and kangaroos using the crossing in its first 12 months and, as the trees and shrubs mature, we’re expecting to spot both koalas and squirrel gliders joining them on the trail. Along with the fauna crossing, we built and installed rope ladders, fauna climbing poles, and culvert underpasses to provide safe locations for animals to cross at other locations along the motorway. Fauna fencing diverts animals to these safe crossings, preventing them from wandering into danger.
Solutions from the scrap heap
Putting waste to work
Using crushed-up-rocks and other natural resources to build roads was once business-as-usual. These days, we’re trying all kinds of ideas to avoid waste and reduce new material use.
For example, we trialled green asphalt (an asphalt mix that includes ground-up recycled truck tyres) for an on-ramp on Queensland’s Gateway Motorway—avoiding sending 250 truck tyres to landfill.
We’ve also used fly-ash (a power generation by-product) and crushed glass in our cement. And we diverted spoil excavated from the NorthConnex tunnels to fill a quarry—that’s now being turned into a 60ha public park.
Creating value for our communities
Parks, cycling and pedestrian paths, playgrounds and public art are lasting ways that we contribute to more liveable local communities and active mobility.
of parkland operated, maintained or delivered by us
social spaces, including playgrounds and barbecue areas delivered or operated by us
of walking and bike paths delivered or maintained by us
artworks installed along our roads
public transport routes use our roads
Working with our neighbours
The projects we deliver involve major works, often conducted over months and years. The future payoff for communities will be better connections and faster journeys, but first, there’s the construction works to get through. We have teams dedicated to working with local communities as projects progress. We regularly invite communities into our projects and improve our design solutions based on their feedback. This might mean redesigning a bike path intersection to improve safety, it might mean building a fauna crossing to protect local wildlife or finding a better way to transport spoil from a worksite.
Some of the ways we connect with our neighbours are:
We consult with local communities to learn what they want from us and our projects, to invite design input and check how we’re doing on meeting their needs. We also track the wider community’s mobility trends via surveys.
We host and attend events (such as open days, festival booths, information sessions, site tours, community liaison meetings) to learn from our communities, share project information and answer people’s questions.
We share project, road safety, maintenance closure and other travel information via advertising (digital, print and outdoor) and media coverage, and via regular newsletters and our various social media channels.
When our projects or other works are impacting residents and businesses, we connect with our neighbours via letter drops, going door-door to chat with residents, and calling and SMSing with specific updates.
We ensure our projects deliver benefits to local communities through creating partnerships with local community services. We also give grants to community groups and run school programs.
Smoother journeys for everyone
Keeping everyone moving on our Australian and North American roads is no small task—our roads are together used by more than 9.7 million customers a year. To ensure our roads deliver the safe and efficient journeys our customers expect, they are hi-tech environments, fitted with all kinds of sensors, CCTV cameras, and even AI and machine learning technology monitoring for issues such as incidents, traffic congestion, air quality and more.
Ensuring smooth travel for our customers helps reduce emissions, improves safety and supports cities’ economic growth and liveability.
Renewing our energy approach
Reducing our reliance on non-renewables is already reducing our operations emissions, with more to come as CityLink transitions to 100% renewable energy in 2024. We’re also upgrading some of our assets with energy-efficient ventilation, lighting and other equipment. And we’ve established mandatory sustainability ratings for all our major projects, for both the design and as-built (construction) phases—further improving our project and operations emissions performance.
Shining a light on energy savings
Our road lighting’s future is getting brighter
Even small changes add up when you’re making those changes on a kilometres-long road—even down to kinds of light bulbs you choose.
LED bulbs use around 80% less electricity to produce the same amount of light as a halogen bulb*—and each of our roads is fitted with 1000s of lights. This includes lights installed before LED lighting technology evolved to be as reliable and versatile as it is today. Replacing our older halogen-bulb lighting with more efficient LEDs is a small change that is adding up to significant energy savings.
And LED bulbs last longer, too, so they create less waste over time. We’re progressively updating lighting on our Australian roads. These small (but numerous) changes are already adding up.
road lighting bulbs replaced with LEDs to date
electricity saved annually
For comparison, the average home has about 37 light bulbs, and lighting accounts for about 7% of the average home’s energy use (or 10% of a home’s electricity budget).
Supporting transit mobility with toll-road revenue
The I-395/95 Express Lanes Commuter Choice program
New and more frequent bus routes, new buses and park-and-ride lot expansions are among the transport improvements a Transurban and Virginia Department of Transportation (VDOT) partnership is delivering.
The I-395/95 Express Lanes Commuter Choice program—that we’ve contributed USD$15 million a year to for the past three years–funds public transport projects that are making it easier for commuters to travel up and down the corridor.
new and expanded bus routes supported by the Commuter Choice program
Our payments are part of a public-private partnership between VDOT and Transurban.
in total, paid over three years, with funds directed to corridor-wide transit initiatives
40 new buses, 9 park-and-ride/bus stop upgrades and 3 bikeshare expansions also delivered through the program
Many of our customers use the lanes I-395/95 Express Lanes to commute to work at the Pentagon and other major employment centres within the region. And this initiative is reallocating toll revenue to motorist’s communities through local-focused transit enhancements.
The transport improvements we’re helping fund are making it easier for people to opt for bus travel or carpooling versus travelling solo in their own vehicle. This reduces congestion and also reduces emissions from having additional vehicles on the road.
To ensure transport’s sustainable future, all transport operators need to collaborate—including across modes and jurisdictions—to create resilient networks that are fair, accessible and affordable, and that minimise environmental impacts over time. This initiative is an example of how this can work in practice.
Live tunnel air quality data
We monitor air quality within our tunnels and, depending on the individual tunnel, may also monitor ventilation air quality and ambient air quality around tunnels.
Visit the dedicated pages below to view available air quality data and information.