With the announcement that the first Level 4 self-driving cars are to be tested on Oxford’s streets next year and then on journeys to-and-from London in 2019 the futuristic vision of automated self-driving cars could be closer to reality than you think. However, the humble pothole could seriously knock that vision off-course believes the Road Surface Treatments Association (RSTA).

Self-driving cars are no longer a futuristic idea. Companies like Mercedes, BMW, and Tesla have already released, or are soon to release, self-driving features that give the car some ability to drive itself. Tech companies are also trying to pioneer the self-driving car. Google has carried out tests of its driverless car prototype on roads in California.

Meanwhile, in the UK trials of self-driving cars have been undertaken in Bristol, Greenwich, Coventry and Milton Keynes and now the DRIVEN consortium, led by Oxbotica, has announced live trials of self-driving Level 4 cars on roads in Oxford and then along the Oxford-to-London corridor. Cars operating at Level 4 autonomy have the capability to drive themselves most of the time without any human input.

Proposed benefits of self-driving cars include increased safety and less accidents and improved usage of road space resulting in less congestion, reduced pollution and more efficient fuel consumption.

However, the utopia of self-driving autonomous cars all equally spaced-out on roads, the potential dangerous impact of human error removed, with the vehicle occupants relaxing as they are driven to their destination could be parked if the road network is not better maintained.

In addition to the need for increased telematic communication and information systems to direct self-driving cars, the road surface must be maintained in top condition for self-driving cars to properly function. The cars will have to be equipped to ‘read the road’ and make allowances for potholes, reduced skid resistance and poor road markings. They will have to replicate the instinctive human ability to almost simultaneously observe, analyse, decide and react. Furthermore, that ability must have the flexibility to adapt to every potential different road scenario. “Given the deteriorating condition of much of our road network the vision of fast self-driving autonomous cars will be a reality of slow-moving vehicle convoys forever in ‘proceed with caution’ safety mode. Rather than a smooth, quiet journey, when travelling on many of our roads the self-driving car’s alarm for approaching potholes would be beeping constantly,” said Howard Robinson, RSTA chief executive.

Robinson points to the 2017 Local Authority Road Maintenance survey (ALARM), published by the Asphalt Industry Alliance, that reported to bring the road network up to a reasonable standard would cost £11.8 billion and would take 14 years to complete. Worryingly, the survey also found that the overall local highway budgets for road maintenance have fallen by 16%.

Robinson continued: “The future vision the autonomous self-driving car is enticing but it must not overshadow the prosaic reality of a potholed, deteriorating road network that can barely cope with the traffic of today let alone that of tomorrow.”