Britpave – the British Cementitious Paving Association representing many leading roadbuilding contractors, designers, machinery makers and materials suppliers – says that autonomous vehicles, all following the same alignment, will soon cause rutting in asphalt and impaired surface skid resistance.
Under plans announced by the Department of Transport self-driving vehicles could be on UK roads by 2025. Cars, coaches and lorries with self-driving features could be operating on UK motorways within the next year, followed by fully self-driving vehicles by the middle of the decade.
The vehicles would be equipped to ‘read the road’ and replicate the instinctive human ability to simultaneously observe, analyse, decide and react to every potential different road scenario such as potholes and reduced skid resistance.
However, self-driving vehicles require well-maintained road surfaces, Britpave says. Surface friction levels, road markings and signs must be in good condition to be correctly read by the vehicles’ sensors. Embedded wi-fi antennae for vehicle connectivity need to be protected from damaged caused by rutting from heavy traffic loads or the road surface melting in extreme temperatures.
Britpave chairman Joe Quirke explained: “The technological advancement of self-driving vehicles needs to be matched by investment in long-term, robust road solutions.”
In particular, he pointed to the fact that, unlike human drivers who may slightly shift left or right within lanes, self-driving vehicles guided by GPS and other navigational aids will follow and keep to a far more precise path. This means that each self-driving vehicle will drive over the same part of the road all the time, leading to significant repetitive wear-and-tear and increased ongoing maintenance.
He said: “To counteract this, roads will have to provide far more long-term robustness than they do at present. They will also have to have far more built-in climate resilience if they are to continue to operate during the extreme weather events predicted as a result of climate change.”
Britpave argues that concrete road surfaces would be better than asphalt for autonomous vehicles, as they have a 60-year design life.
“Concrete roads offer the robustness and resilience to withstand repetitive traffic loads as well as the structural integrity to support and protect installed sensors and wi fi antenna,” Joe Quirke said. “A self-driving vehicle will only be as good as the road surface that it drives on.”