Pothole project developing smarter roads for the future

But first, the UK’s leading motoring associations - the AA and the RAC - have said the country’s potholed roads are largely to blame for a huge surge in vehicle breakdowns. Potholes are usually formed when water freezes in cracks in the road and expands. Engineers here in Cambridge are working on a research project to do something about it. One aspect of that is knowing where the potholes are in the first place and, as it turns out, that the new generations of high-tech, sensor-laden cars on our overcrowded roads are already generating reams of data about the road condition.

This, the Cambridge team intend to mine and then act on by deploying autonomous vehicles to patch up damage almost before it even gets started, using new self-healing road surface materials and embedding sensors in the roads to make the job even easier. I went along to meet the brains behind the project, pothole saviours Professors Ioannis Brilakis and Abir Al-Tabbaa…

Ioannis - The car industry has evolved dramatically over the last 40 years and is now able to give us, in real time, an amazing wealth of information. They can detect cracks, potholes, fallen street signs, damaged lane markings. It's just we have no way of taking that on board.

Chris - Are you saying modern cars, because they're endowed with all these cameras and sensors, they're just naturally passively collecting all that information anyway?

Ioannis - Yes. Some of the car companies we work with collect something like 50 gigabytes per minute. They process that onboard, come up with these detections and only share those detections in a statistical way. In other words, at least three vehicles of the same type need to go over that defect before this is reported.

Chris - Where does the data go then? It's stored on the car. Does it then get shared centrally with the manufacturer?

Ioannis - Yes, it goes straight to the manufacturer's cloud and then this is where we come in. The plan is to have a cloud system, a digital twin if you want, of the physical infrastructure that is able to take all that information, start making decisions. What does this change mean for me? Do I need to go and right now fix the problem? Or is it a problem that can wait for the next maintenance schedule and then as a result of that, send that information onto a maintenance vehicle, or to humans to make decisions.

Chris - Does this mean we can potentially get ahead of problems? You don't wake up one day and the road has a one metre across breach in it. That must start as a very small breach that then gets worse and worse and worse. So does this mean we can potentially get upstream of some of these problems and fix them before they even become a headache for motorists?

Ioannis - Imagine a world where, rather than us inspecting the roads once a year or once every two years, as soon as three vehicles drive on top of a specific defect, it's already detected and reported. That means that potholes will never form again anytime in the future. We can fix them well before they even materialise.

Chris - And who will do the fixing and how?

Ioannis - That's where our colleagues in the smart materials area come in. We have effectively autonomous vehicles that have the added function of being a repair vehicle, who can come in then and address that problem.

Chris - Do they already exist? These autonomous vehicles, though?

Ioannis - They don't. And this is another element of the project we're trying to create. We have already a team of people on the robotics front as well as the smart materials end who are trying to come up with a multipurpose vehicle that doesn't just solve one problem, but also does it using smart materials that are able to be much longer lasting and able to sense themselves and give us information that they would otherwise not have.

Chris - So there you are, Abir, you'll know where the problem is, how big it is, and how urgent it is. Now it's over to you. How are you going to fix it?

Abir - Yes. So we're going to make use of the data to understand the condition of the road, decide where to perform proactive maintenance, what damage needs to be fixed, and at the same time make the road smarter so that the road communicates with the vehicle on its state of health.

Chris - Ah, you're really delivering two solutions here then. One is using the data we've just been hearing about to optimise and get ahead of problems as they're emerging, but then also make the road itself better so that it's basically more resilient and better at telling us when it's got a problem going forward.

Abir - Exactly. The plan is that we can introduce additives in the materials, they can tell us where there's strain, where there's stress, where there's water ingress, but at the same time we can embed some sensors so they can, again, report back to their state and condition and provide, add materials that will enhance the resilience so they last longer. Potentially they could self-heal as well so we don't even have to worry about inspecting the pavements.

Chris - Well, let's think about those two things in turn. The sensors first, what are they, how will they work and what sort of information will they deliver that we can't just learn from the cameras on people's cars already?

Abir - They will provide inside information because our pavements are layered and there's depth. The vehicles very much provide data on the surface of the road, but many of the problems start from underneath. So we can actually, by embedding those sensors, detect potential problems even earlier.

Chris - And, in terms of the materials, what are the new materials that we could use that will make potholes a bit less common?

Abir - So we can provide more resilient materials. They are stronger, they last longer, they bond more with a substrate, but also provide materials that are self-healing. So if a small crack occurs,, they heal the damage themselves. So you don't even have to go and repair them.

Chris - How do they do that?

Abir - A simple solution is capsules which contain a healing agent in them. You embed those in the pavement. A crack will just propagate through these capsules and rupture them and the healing product comes out and seals the crack.

Chris - It sounds amazing, but this sounds also expensive. Is this going to be new roads going forward, and we put this into a road as we build a road, or is it retrofittable? Because it sounds to me like you're going to have to dig roads up one way or the other to get these new materials in, but also to get the sensors in?

Abir - It will be both of them. So you can apply self-healing repair materials. You can also apply self-healing as a coating. For example, some cars have self-healing paint on them. So you don't have to dig the pavement and embed those materials in it. They could be applied to the surface.

Chris - What sort of a difference do you think this will make, ultimately, if we are able to implement this? How is this going to turn things around?

Ioannis - I think we need to look at this as a long-term and a short-term solution. On the long-term front, yes, it will take us a long time to replace all of our pavements, but the same thing happened with traffic lights when we went from incandescent light bulbs to LEDs. This didn't happen overnight. We gradually replaced them. Also, in terms of the roads themselves, we don't have to dig up the whole road. Sometimes it's just a top layer that could be resurfaced and resurfacing is something that happens fairly frequently on many of our roads. So it'll be something that will take many years, perhaps even a couple of decades, but it is possible to update the whole network. Roads in this country carry 70% to 80% of all goods and people, this is not going to change in the future. This has been stable for quite some time, and at the same time, it's a very underfunded mode of transport. It receives only 15% of the public spending, so unsurprisingly, without enough money, and if we hold that traffic, we have problems and we have to change that.