Q&A Series #09: Interview with James Loney

The topic of discussion: Road pavements and sustainability

The conversation around road pavements and sustainability stems from the drive in the industry to not only look at the use of recycled materials but also explore other methods of preventative maintenance of existing assets. There are many technologies now that extend the life cycle of pavements with the ROI for the asset owner. The acceptance by contractors and asset owners to adopt and adapt to new methodologies is critical in the management of road pavements as assets. The key balance is between higher initial cost but lower long-term maintenance and rehabilitation cost and whether it’s more economical than the pavement with lower initial cost and higher maintenance and rehabilitation cost. Life Cycle Cost (LCC) should be the prime factor to be considered. So, what is the synergy between road pavements and sustainability?

In this article, we learn more about road pavements and sustainability from James Loney, a Chartered Professional Civil Engineer with a history of working in the field of Pavement Engineering. 

1. Where do you derive your passion for sustainability in pavements from? 

I have always been into recycling and sustainability even before I worked in the pavement industry. I have always tried to be environmentally friendly in my personal life. Once I started working in the pavement industry, I could see that there were lots of opportunities to make a bigger impact on sustainability when designing, testing, constructing, and maintaining pavements so I started putting more focus into that. I believe many are in roles where they can make a bigger impact on sustainability through their work practices more so than in their personal habits. 

2. How would you describe a pavement as an asset? 

A public road pavement is a resource that provides current and future value to a nation. It provides economic value by allowing for freight and trade. It provides value to all in society by allowing access to services such as hospitals, schools, markets, sports, and many others. It is well documented that good quality infrastructure has massive economic and social benefits to a community.

3. What is the importance of the 3R’s of sustainable pavement design, construction, and maintenance? 

The 3Rs (Reduce, Reuse, Recycle) sound catchy, but the most important “R” for sustainable pavements is to Reduce. Reusing materials in place or recycling them into new products are alternative methods of reducing how much we use but it is always better to try and reduce first. We can reduce in many ways from designing longer-lasting pavements to ensuring high-quality control during construction. We need to reduce how much waste we create, and we need to reduce how much finite resources we use until we reach the point where we are no longer compromising the needs of future generations. 

4. Are net-zero emissions in pavements an achievable goal?  

Yes, they are achievable.  Many nations have committed to at least halving emissions by 2030 and achieving net-zero emissions by 2050. I believe this is achievable and for some nations and businesses, I think they should aim for net-zero much sooner than 2050. Strong commitments have been made but we still need to see the actions.

Net-zero is the minimum requirement for sustainability however it will not reverse the climate change that will have already occurred by 2050 which may still be significant. Once we get to net-zero we also need to look at reversing some of the damage done. For now, I think net-zero is a good target to aim for to keep people focussed. 

5. What challenges are currently faced in adopting and adapting to sustainability in pavements? 

Often the only metric used to compare pavement construction/rehabilitation options is the initial costs. There needs to be increasing value placed on more sustainable solutions even when the initial costs may be higher. We need to look at the full life cycle costs and the environmental impacts when comparing different pavement construction options. The carbon cost of alternative options needs to be considered along with the long term economical costs.

Pavement construction projects need to have more funding at the design and investigation stage. This would improve the overall outcome and sustainability of the pavement construction options selected. Reusing insitu pavement materials requires more time and costs at the design stage. This is because we need to test the existing pavement materials to ensure they are suitable and if they are not suitable, we can engineer ways to improve them in-situ. 

There can sometimes be resistance to new ideas, especially when investing large sums of capital. In many ways this is understandable. Pavements are investments that are designed to provide value for many years and an issue we have with some new innovations is that they have not had time to be well proven over the full life cycle of the asset. For this reason, we need to see more trial projects and funding into research.

Many have committed to the goal of net-zero by at least 2050 but we still need to see more detailed plans on how we will achieve this goal and following that we need to see strong actions. The main action from governments that could lead to improvement on all the above-mentioned challenges is to have more legislated efforts from the top down that promote asset owners and others in the industry to innovate and drive the changes we need. 

People need to want this also. If the political will of the people is not aligned with a target of net-zero emissions then we will not get there.

6. Which other innovative technologies and opportunities are available to improve sustainability when constructing or maintaining pavement assets? 

There are many examples of new technologies and innovations for constructing and maintaining pavement assets present in almost every stage of pavement construction. Most of these technologies are not new but unfortunately, they are often not widely adopted.

For field testing, we have more tools now to measure and test pavement performance. To determine the best solution, we need to test and measure existing pavements. Falling Weight Deflectometers (FWD) and Ground Penetrating Radars (GPR) for non-destructive pavement investigations are becoming more mainstream and affordable at a local government level. 

In the design and research space, our knowledge of pavement materials is increasing every year which allows us to accurately predict material performance in the field and select more sustainable solutions.

More specialist interlayer treatments are available, such as geofabrics and asphalt reinforcement grids, which can improve pavement life.

The materials we use to construct pavements are using more and more recycled materials each year without compromising the performance of the material. There is equipment for in-situ recycling of pavement materials which provide huge costs and environmental benefits.

During construction, the equipment being used is becoming more and more advanced. For example, modern rollers are equipped with an integrated measurement system referred to as Intelligent Compaction. This provides live feedback directly to the operator on the level of density achieved and the number of passes on each area.

7. Globally, how do you envisage the sustainable pavement movement in the next decade. What are your predictions? 

I envisage that we will see more incentives and bonus schemes from the government level to corporations who try to innovate and improve sustainability. This must happen for us to achieve our goals.

I expect to see more field trials and pilot projects of innovations and new ideas for improving sustainability within the pavement construction and maintenance industry. I think this is the most critical area that needs investment if we are to achieve our sustainability goals.

The rising costs associated with the disposal of waste and the purchase of virgin materials will provide further economic incentives for more sustainable pavement rehabilitation/construction practices. There are very few pavements today that are constructed without some level of recycled materials which is increasing, and I expect this trend to continue as long as we continue to support and reward innovation. 

I am hopeful that net-zero emissions will be the big-ticket item during the next election cycle for most nations as the next 5 to 10 years are critical in setting the foundation for achieving this goal. I am optimistic that most advanced economies will reach the 50% emissions-cutting target by 2030 and then net-zero by 2050 if not sooner as long as we see some strong actions over the next few years.

Unfortunately, it is expected that the global temperature will rise by at least 1.5°C even if we achieve net-zero by 2050. We will have more work to do once we achieve net-zero. For now, however, we need to focus on getting to net-zero first as soon as possible.