Features & Interviews TNB News

Michael McHale, TRL, on potholes: lessons learnt and future solutions

11 April 2019 #Features & Interviews #TNB News

When it comes to delivering transport solutions for the future, zero emissions electric vehicles and all manner of technical innovations spring to mind. Few people, though, will think about how improvements to the road surfaces themselves can effect real change. Michael McHale, Pavement Engineering Lead at TRL gives his opinion.

The first thing most people think of when considering the challenges for road surfaces would be the infamous pothole. In fact, while it is essential to repair potholes to keep road users safe, they are merely a symptom of the many underlying causes that effect the quality of a road’s surface.

When it comes to solving the pothole crisis in the UK, experts at TRL suggest that treating these defects is simply not enough. Potholes are a symptom of road surfaces that are not fit for purpose because of the changes transport has endured over the years and most importantly, due to a lack of funding.

Many factors come into play when identifying the real cause of poor-quality road surfaces in the modern world. Increasing populations, growing numbers of vehicles on the road, rising consumer demand and the advent of online delivery services have all had an impact on the durability of roads due to increasingly frequent use.

Consider the arrival of GPS; this innovative technology has made it easier for road users to navigate UK infrastructure, while in turn, it has resulted in heavier traffic flows with heavy vehicles utilising routes that may not have seen these levels of traffic previously or may not have been designed for this type of use to begin with.

Treating the cause, not the symptom

To lay a solid foundation for the UK infrastructure, and prepare road surfaces for the future, a focussed engineering strategy is needed in the approach to potholes. Engineers and authorities must look at solving the causes of potholes, rather than treating the symptom.

Well-engineered, regularly maintained road surfaces and the use of quality materials is the only real way to defeat the notorious pothole. Strategies that focus on proper maintenance of road surfaces before they deteriorate would prevent a huge number of defects seen on UK roads.

Sealing, strengthening and renewing road surfaces are the most important ways that defects can be minimised through preventative maintenance. These may seem like disruptive and expensive measures, but in terms of whole life cost they could eradicate potholes and prove more cost effective.


Challenges with new technologies

Modifying road surfaces to accommodate connected and automated vehicles present a variety of challenges for the future. Installing sensors throughout the network will be the first hurdle. Roads may also become burdened with increasing wear and strain if connected vehicles all follow a set singular path.

Ultimately, the main challenge for engineers and authorities has remained the same since the 1800s, producing longer lasting, more durable road surfaces.

The road surface industry is currently developing and trialling a range of new surface materials to provide longer lasting roads. The latest innovation gaining attention is the ‘plastic road’. Surprisingly, the amount of plastic in this form of modified bitumen represents less than 0.5% of the mixture.

But while the use of modified bitumen is not a new concept, it is concerning that there are currently no standards and specifications surrounding bitumen modified with plastic. More troubling perhaps are the issues of what happens to the plastic waste biproducts when these surfaces deteriorate. The implications to the environment and surrounding ecosystems should be studied more widely before these surfaces are rolled out nationally.

The road to the future is paved with lessons from the past

With the increasing changes and challenges we face in planning the future of transport, there is a growing need for advanced engineering, proper maintenance and increased funding to ensure our infrastructure is fit for purpose.

TRL has been working alongside Transport Scotland to develop a cutting-edge new surface course material. The material, known as TS2010, has the potential to last for 20 years, twice as long as many materials currently used throughout the road surface industry, effectively doubling the life expectancy of UK road surfaces.

Introduced in November 2010, TS2010 has been through extensive development and is now well into the assessment phase. Annual visual assessments indicate the material will last twice as long as materials previously used on Scottish trunk roads.

Maintaining the UK’s extensive road network is vital for the future of transport. There are rapid changes ahead for the transport sector with the arrival of connected and automated vehicles and electric and ultra-low emission technologies set to change the face of UK infrastructure.

Advances in technology are set to change the face of transport, making it crucial to innovate road engineering principles and practices to ensure the UK’s infrastructure is fit for purpose.

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