This quarter promises to be a period of significant progress across our six research streams, paving the way for a safer, more sustainable and resilient future for Queensland’s transport infrastructure. As we approach the new financial year, we’re filled with optimism and excitement for the discoveries and breakthroughs that lie ahead.

Our May newsletter will provide you with all the latest updates across our wide offering of research areas:

• Pavements
• Asset Management and Heavy Vehicles
• Structures
• Sustainability and Resilience
• Road Safety
• Network Operations

Please enjoy our newsletter and feel free to contact us via our website if you have any questions or innovative research ideas.

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Pavements:

Innovation for Greener, Smarter Roads

Queensland’s roads are on the fast track to sustainability, thanks to the ingenuity of NACOE’s Pavements stream. Two recent projects showcase our commitment to tackling key challenges with safe, efficient and environmentally friendly solutions.

Reducing Cutter in Crumb Rubber Seals:

How could Queensland achieve greener seals that utilise recycled materials? One aspect of P131 explored the potential to reduce or eliminate the amount of ‘cutter’, a solvent traditionally used in seals when constructing at lower temperatures, used in crumb rubber-modified binder (CRMB) seals. Cutter is often used in CRMB roads in Queensland and reducing its use in CRMB seals would result in environmental and safety benefits. Field trials undertaken on TMR projects compared standard CRMB seals sprayed with cutter against lowered-viscosity CRMB seals sprayed without a cutter. The results were promising. Both binders sprayed well, with the lower-viscosity option showing minimal surface imperfections after construction. This paves the way for ongoing analysis and review towards identifying a more sustainable CRMB sealing alternative. By exploring this potential, P131 is helping pave the way for a future where Queensland’s roads are safer, more efficient and environmentally friendly.

Safer, Faster Road Surface Texture Measurement at the Project Level:

(Note: This project does not investigate or assess surface texture measured using vehicle-mounted lasers for asset management purposes.)

Measuring road surface texture at the project level has traditionally been a time-consuming and potentially risky task utilising manual sand patch tests. Project P144 explores the potential of using a safer, faster alternative for project-level testing (e.g., for seal design inputs) that uses hand-held (portable) laser-based technology. Field trials compared surface texture measurements from a hand-held laser device with the sand patch surface texture depth measurements on various surfaces. While a reliable relationship between the hand-held laser device and sand patch texture depth outputs was developed for smoother surfaces, it faced challenges with sprayed seals, which typically have more texture than asphalt. The equivalent sand patch texture depth calculated from hand-held laser device measurements was often underestimated in these cases. Undeterred, the project continues to explore alternative analytic approaches to adjust the hand-held laser device’s output to align with the sand patch texture depth results for sprayed seals. If this can be achieved, the use of the hand-held laser will offer numerous benefits, including faster and more efficient texture measurement, with a simpler and less involved collection method for the operator, which reduces safety risks as operators spend less time on the roadway. These innovative projects exemplify the NACOE Pavements Stream’s commitment to innovation with a focus on efficiency and safety. By assessing potential cutting-edge solutions we can help contribute to safer, more efficient and sustainable roads for Queensland, paving the way for a brighter future for all.

NACOE welcomes new Pavement Stream Leader, Sam Afkar!

Samad Afkar started with the NACOE program in 2021 and is an industry award-winning pavement engineer specialising in pavement and road asset management. Sam brings a wealth of experience delivering innovative solutions, R&D projects, trials and practical solutions for industry issues to provide better value for money, more quality outcomes and more efficient solutions to the road pavement industry. Sam has been heavily involved in implementing intelligent compaction, including developing the specification and technical guides, field trials and associated data analysis with TMR and MRPV. Sam also brings expertise in modelling, forecasting and asset planning for road assets and has been instrumental in the implementation of road asset management systems, such as the development of data collection packages (manual and automatic), databases and their respective software packages for analysis. NACOE is thrilled to welcome Sam into this new role and benefit from his extensive project management experience in design and operations, leading trials, system implementations and road construction projects. We would also like to acknowledge and thank outgoing Pavement Stream Leader Neera Vishnubhatla for her valued contributions to the NACOE and wish her the very best with her future endeavours.

Asset Management:

Alternative Binder Attributes and Associated Test Methods to Inform Surfacing Life

Our Asset Management team has been researching the performance of sprayed seals and asphalt surfacing in Queensland for several years. Initially, the research on sprayed seals was focused on identifying alternative binder attributes and associated test methods to inform surfacing life. The team characterised the binders using the dynamic shear rheometer to test recovered binders as an alternative to the ARRB durability test. The research continued with field assessments to validate a preliminary surfacing life relationship developed under A20 for various sites across Queensland using an adaptation of the VicRoads Surface Inspection Rating method. A comparison of field data and the surface life estimates obtained using the Queensland adaptation of the established ARRB Binder Oxidation Model will help inform better estimates of the life of these critical treatments and further research. The project also focused on accurately estimating the lifespan of asphalt surfacings, both open-graded and dense-graded types. This estimation greatly assists investment planning and prioritisation within the Maintenance, Preservation and Operations (MPO) program. It enables the estimation of ravelling or loss of surface aggregate, which, according to a recent TMR survey, is the second most common reason after surface cracking, for replacing asphalt surfaces. With changing technology, materials, specifications, and performance expectations, there are currently many different forms of asphalt surfacing, such as dense grade (DG), stone mastic (SM), open grade (OG), and high modulus EME. AC surfacing, SM, and OG asphalt mixes typically can contain polymer-modified binders (PMB), while some project-specific OG and gap-graded asphalt mixes can contain or crumbed rubber-modified binder (CRMB). Given the range of asphalt surfacing using different bitumen binders and mixes, it is highly likely that there will be a variation in the service life for different types of asphalt. Therefore, this initial study prioritises DG and OG mixes. In addition, other factors can influence asphalt surfacing service life, such as location and placement on bound and granular bases and deep lift asphalt.

Understanding the Pavement Impacts of Low and Zero-Carbon Heavy Vehicles

Our asset modelling, future vehicles and freight, and pavements teams are working on A68 to assess the potential pavement impacts that heavier low and zero-emission (LZE) vehicles will have on the pavements in the state road network and the resulting changes to the future asset management.

The project is aimed at:

• Developing and applying estimates of the future freight task, including the migration to LZE vehicles, with a range of forecast scenarios from low to very high uptake, including for different locations in the state.
• Understanding the resultant pavement impacts, including a review of the state of knowledge on pavement impact models (for vertical and horizontal loading) and the evidence base considering the configurations that apply now and in the future.
• Undertaking a preliminary assessment of agency costs for several scenarios and recommendations for further research.

Key stakeholders in Australia’s transport network have shown interest in the work, which has led NTRO to develop a pavement modelling analytical framework, data specification and case studies for for potential application by other transport jurisdictions.

Road Safety:

Our road safety researchers are diligently laying the groundwork for solutions to protect vulnerable road users and create a safer travel environment for all. Literature reviews inform best practices, stakeholder workshops bridge the gap between research and real-world needs, and data analysis is poised to illuminate key insights. Keep an eye out for updates on projects R144, R146, and R148 as they delve into critical areas like intersection safety, pedestrian crossings and work zone protection.

Celebrating David McTiernan

NACOE also celebrates the hard work and dedication of David McTiernan, NACOE Road Safety Co-Stream Leader. His tireless commitment to road safety and innovation has been recognised with ARRB’s top Honor of Meritorious Service Award 2024. David’s recent insights and contributions shared through his Sydney Morning Herald story (note: may be pay-walled) shed light on the potential reasons behind the terrible year for road fatalities in 2023. Let’s draw inspiration from David’s achievements and continue working towards a safer and more responsible future on our roads.
EXPLORE PUBLICATIONS
READ SMH ARTICLE

Structures:

This year, we’re thrilled to announce NACOE’s participation in Copenhagen’s prestigious IABMAS 2024 Conference. On June 24—28, our Structures experts will present findings on enhancing safety on timber bridges, including feasibility and risk assessment of bridge barrier implementation (NACOE project S68). This important project explores innovative solutions to improve the safety of timber bridges, a crucial step towards a more resilient and sustainable infrastructure network. Beyond the conference, our Structures research continues to push boundaries. Stay tuned for developments on fatigue behaviour in concrete joints, post-tensioned girder management and pre-tensioned girder behaviour — research that will ensure the longevity and safety of Queensland’s bridges.
EXPLORE STRUCTURES PAST PUBLICATIONS

Sustainability:

Sustainability is an important component of the NACOE research program, and we’re proud to see our research translate into tangible results. Our Sustainability teams’ research into the use of recycled materials in earthworks and drainage materials has taken a major leap forward, with successful field trials demonstrating the viability of incorporating recycled materials into road construction.
READ O25 REPORT
WATCH O25 WEBINAR

Recycled Materials Supplier Dashboard Webinar:

Furthermore, our ongoing webinar series continues to educate and inform the transport community. The recent O28 webinar on the Recycled Materials Supplier Dashboard, presented by Steve Hulme and Jaimi Harrison, garnered widespread interest, highlighting its potential to streamline adopting sustainable practices. On March 15, NACOE hosted a joint webinar event with research partners WARRIP to present the Safety and Sustainability of Recycled Plastic in Road Infrastructure, hosted by Dr Chrysoula Pandelidi and Dr James Grenfell. The webinar enjoyed high attendance and delved into the safety and sustainability of recycled plastics in road infrastructure—a timely topic with far-reaching implications.
WATCH O28 WEBINAR

Network Operations:

Queensland’s roads are getting smarter, thanks to NACOE’s Network Operations stream! We’re using data to unlock solutions in key areas:

Unlocking Powerful Data:

Our ongoing project is building a user-friendly traffic data access portal, empowering TMR officers to instantly retrieve and analyse data from diverse sources. Gone are the days of complex data manipulation; this streamlined portal simplifies reporting and enables data-driven decision-making, planning, and policy development for the entire transport network.

Improving Traffic Insights:

We’re delving into international AADT (Average Annual Daily Traffic) calculation methodologies, developing a novel ‘proof of concept’ using historical traffic data. This project aims to improve the accuracy and coverage of volume data, impacting crucial areas like infrastructure investment, network planning and policy development. Imagine having precise traffic patterns guiding resource allocation, leading to more efficient infrastructure projects and data-driven policy decisions? That’s the power of accurate traffic data.

Enhancing Asset Management:

We’re conducting a comprehensive review of TMR’s maintenance practices for current and future ITS (Intelligent Transport Systems) and electrical asset maintenance practices. This, aligned with the road maintenance performance contract, will update work activities to ensure efficient procedures for today’s and tomorrow’s needs. Think longer-lasting infrastructure, optimised resource utilisation and smarter asset management.

Expanding Active Transport Data:

We’re embracing the rise of new technologies, exploring their potential to expand the existing active transport data landscape. By identifying metrics that assess the suitability of various data sources for travel measurement and business outcomes, we aim to enhance data availability and support informed strategies for promoting active transport options. Imagine a wider range of data sources providing valuable insights for promoting cycling and walking – that’s the future we’re shaping. Our research findings are making a difference. At the recent Australasian Transport Research Forum, we presented Project R117, “Impact of using hybrid data on travel time reliability reporting”. This research conclusively demonstrated the benefits of hybrid data, offering superior data coverage and reliable travel time values compared to traditional methods. This translates to a simplified data experience for practitioners and valuable insights for improved network management. Stay tuned as we unlock the transformative power of data, delivering innovative solutions for Queensland’s smarter, more efficient roads.

Looking ahead:

This is just a glimpse into the dynamic world of NACOE research. As we progress through the year, we invite you to stay connected, engage with and share the innovations and discoveries shaping the future of Queensland’s transport infrastructure. Visit our website and join us on social media for regular updates and insights. Together, we can build a brighter future for our roads, communities and planet.