From Trial to Business‑as‑Usual: Crumb Rubber Asphalt on Local Roads

Overview 

In 2021, the City of Greater Dandenong partnered with Tyre Stewardship Australia (TSA) and the National Transport Research Organisation (NTRO) to trial a new Light Traffic Crumb Rubber Asphalt (LTCRA) specification on a local road in Keysborough, south‑east Melbourne. The aim was practical: to test whether crumb rubber asphalt could perform at least as well as conventional asphalt on lightly trafficked council roads, while creating a reliable end market for tyres at end-of-life. 

Five years on, independent monitoring shows the trial section has remained in consistently good condition, outperforming a comparable control road resurfaced atround the same time with conventional asphalt. 

Project context 

In 2019, the Victorian Department of Transport and Planning (then VicRoads), working with NTRO and Sustainability Victoria, introduced Specification 422 – Light Traffic Crumb Rubber Asphalt. This was a critical development: by embedding crumb rubber into a state specification, councils and contractors could specify and supply these mixes with confidence rather than treating them as bespoke or high‑risk alternatives. 

To accelerate uptake, TSA provided combined grant funding of $500,000 to councils willing to trial the specification in real‑world conditions. The City of Greater Dandenong was one of six Victorian councils selected. 

“This trial was about proving that crumb rubber asphalt can perform where councils need it to, using a standard specification they can rely on.” Tammie Miller, Head of Market Development, Tyre Stewardship Australia. 

The site and construction 

Location 

• Road: Church Road, Keysborough (east of Chapel Road) 

• Length: 250 metres 

• Road type: Lightly trafficked local road 

The section was chosen because it was already showing signs of fatigue, including cracking, binder loss, and surface unraveling. Left untreated, these defects would have allowed water ingress and accelerated deterioration. 

Installation 

• Asphalt type: 10 mm LTCRA (Specification 422) 

• Layer thickness: 35 mm wearing course 

• Construction date: May 2021 

• Supplier: Fulton Hogan 

In total, around 183 tonnes of asphalt were laid, incorporating 19.6 tonnes of recycled material — the equivalent of 128 used passenger vehicle tyres. 

The LTCRA layer was placed over targeted patching works using conventional asphalt, addressing existing weak spots before resurfacing. 

Monitoring approach 

Independent, long‑term assessment 

NTRO undertook a five‑year pavement monitoring program (2021–2025), using its network survey vehicles and falling weight deflectometer equipment. Monitoring was deliberately comprehensive, covering both surface condition and structural performance. 

The assessment included: 

• Roughness (ride quality) – International Roughness Index (IRI) 

• Rutting – transverse deformation across the lane 

• Surface texture – skid resistance indicator 

• Cracking extent – percentage of surface area affected 

• Pavement strength – deflection and curvature measurements 

To provide context, NTRO also assessed a control site on View Road, Dandenong, in the final year of monitoring. This road was resurfaced in 2021 using conventional asphalt and had a similar pre‑construction condition. 

Project results  

Over five years of independent monitoring, the LTCRA surface on Church Road held its condition with no notable defects reported, while the conventional asphalt control section showed more variable performance.  

The clearest separation was in cracking: the LTCRA section remained effectively crack‑free at the end of monitoring, whereas cracking was present on the control site, including segments in ‘poor’ condition.  

Across the other functional indicators, the LTCRA section stayed comfortably within ‘good’ ranges for ride quality and rutting and compared favourably on texture. Taken together, the results suggest LTCRA can deliver stronger short‑to‑medium term performance on lightly trafficked local roads. 

“What’s exciting here is not just that the road performed well — it’s that it did so consistently, year after year, under routine traffic conditions.” Tammie Miller, Tyre Stewardship Australia. 

What this means for councils 

This trial demonstrates that LTCRA can match — and indeed exceed — the performance of conventional asphalt on lightly trafficked roads, when designed and installed under a standard specification. 

Key takeaways for asset managers include: 

• No observed trade‑off between recycled content and pavement performance 

• Stable condition over five years with minimal maintenance intervention 

• Clear evidence to support broader specification and procurement 

“This is the kind of evidence councils need: local roads, local conditions, independently measured over time. It shows recycled materials should be part of everyday road management, not just pilot projects.” Tammie Miller, Tyre Stewardship Australia 

Looking ahead 

NTRO recommends periodic monitoring to track longer‑term surface texture behaviour and to investigate the atypical increase in texture measured over time.  

The bigger shift, though, is that councils now have clearer pathways to move from one‑off trials to routine delivery. TSA’s Market Development Fund provides co‑investment for projects that build real demand for tyre‑derived materials — including grants up to $300,000 across demonstration/infrastructure and R&D streams. In parallel, TSA and the Australian Flexible Pavement Association (AfPA) have supported the release of a CRM DGA Model Specification for light‑to‑medium duty roads, giving councils practical, consistent guidance designed for the types of roads they manage.  

For councils and asset managers, the Church Road results sit in the innovation sweet spot: independent performance data, a fundable pathway for implementation, and an emerging national specification base — the combination needed to make crumb rubber asphalt business‑as‑usual rather than exceptional.  

Interested in doing something similar in your council? TSA’s Market Development Fund offers project funding of up to $300,000 to support council‑led trials and infrastructure projects. Learn more here.

Additional resources:

Full report: National Transport Research Organisation (NTRO), Light Traffic Crumb Rubber Asphalt Demonstration Trial – Final Condition Monitoring Report, 2025.

CRM DGA Model specification

TSA Resources for local government: https://www.tyrestewardship.org.au/what-we-do/market-development-funding/lg-resource-centre