Most people look at a road and see tarmac. There is a kerb at either side, perhaps a drainage gully nearby, road markings on top and a dark surface carrying thousands of vehicles. It is easy to assume that the visible asphalt represents most of the road construction. In reality,…

Roundabouts are designed to keep traffic moving efficiently, but from a road surfacing perspective they create a demanding environment. On a straight section of road, most vehicles travel forwards with relatively limited steering input. Their tyres predominantly apply vertical loads as they roll across the surface. A roundabout changes that…

Drive along an otherwise reasonable stretch of road and you may notice something interesting. The straight sections can remain relatively smooth while the surface around a bus stop, junction or traffic-controlled intersection shows cracking, depressions, polished areas or distorted tarmac. This is not simply coincidence. Road surfaces behave differently depending…