Planning for low-build solutions to achieve Net Zero

In late 2023, WSP and AITPM held an interactive national webinar on ‘Planning for low-build solutions to achieve Net Zero’ to explore industry sentiment toward decarbonisation and discuss how our approaches can be better adapted to address decarbonisation needs.

Peter Kartsidimas, Director Research and Policy at Infrastructure Victoria, discussed the impacts of different growth scenarios for Melbourne. Tim Sullivan, Principal Transport Planner – Net Zero, and Sara Stace, Regional Executive of Infrastructure Advisory, both from WSP Australia, outlined how better planning approaches can reduce the distance requirements and demand placed on the transport system, and therefore carbon emissions. Simon Pope, Technical Director, WSP in the UK, shared some insights from the UK on carbon budgeting and measurement.

We also surveyed industry and AITPM members, both before and during the webinar, to see how they felt about climate action and their ability to make an impact. We found that: 

There is clearly a desire to do more to address climate change amongst many transport professionals. This came through strongly during the webinar discussions as well as the survey results. To continue our industry’s progress towards more sustainable transport solutions and to build on momentum from the webinar, here are three actions that every leader and transport planner can take today:

Get acquainted with carbon budgets!

Over the last 12 months, the Australian Government’s Climate Change Act 2022 (Cth), NSW Climate Change (Net Zero Future) Act 2023, and Queensland Clean Economy Jobs Act 2024 have enshrined carbon reduction targets into law. We don’t talk much about carbon budgets in Australia, but it’s useful to think about the carbon impacts of your projects and proposals in the same way that we think about monetary costs. We should be working to a finite carbon budget just as we do with a dollar budget. And we can do this at any scale, from an individual scheme to a state-wide strategy.

Consider alternative performance metrics for your projects

Many transport modelling and engineering professionals will be familiar with traditional traffic engineering metrics such as level of service (which measures traffic delay). On road-based projects, think about alternative indicators which reflect the holistic outcomes we should be aiming to achieve with public road space. The NSW Government built environment indicators provide a good example. Remember – what gets measured, gets managed!

Challenge the assumption of perpetual traffic growth

Conventional traffic forecasting presumes inevitable growth in vehicle movements. Yet as the table below shows, the data tells a different story for Greater Sydney's arterial roads, where average daily traffic volumes have dropped by around 20 per cent over the decade to 2021. ‘Peak car’ travel occurred in 2004 across all our major cities, meaning that the average Australian is travelling less by car every year and this trend is continuing downwards. By challenging the continuous upward trajectory of traffic growth, we can reconsider the necessity of building more road infrastructure with embodied carbon and materials. It's a call to align our planning with the evolving realities of urban mobility, ensuring that our investments are both sustainable and responsive to actual transport trends.

It's clear from our discussions and feedback that transport professionals are eager to integrate climate action into their work. The takeaways from our webinar are practical and straightforward:

Firstly, every project is an opportunity to champion decarbonisation. We can start by raising with our clients the role of decarbonisation and carbon budgets and incorporate this as a routine part of our project methodology. As Infrastructure Victoria and the NSW Government have pointed out, compact development centred on public transport is far more efficient for the economy and climate, so perhaps we don’t need more road building to access the outer urban fringe.

Secondly, we should use any opportunity to introduce broader performance metrics that shift the focus from traditional traffic flow to broader place and wellbeing outcomes. The Australian Transport Assessment and Planning Guidelines (ATAP) are currently being updated with this in mind; however we also need to more comprehensively incorporate a ‘vision and validate’ approach to achieving outcomes, rather than ‘predict and provide’.

And thirdly, we should challenge growth assumptions by using data-driven insights to question the inevitability of traffic growth and re-evaluate infrastructure needs.

Tim Sullivan and Sara Stace are members of the AITPM Policy Working Group, which is currently developing a Decarbonisation Position Statement. Please contact Tim or Sara if you'd like to discuss working together to further decarbonisation action in the transport industry.