He told the Highways UK event last week that he does not see a business case for the widespread use of connected autonomous vehicles (CAVs) on a large scale, in the short to medium term.

“If you look at who is pushing autonomous vehicles it is not the public,” he said. “I think the majority are happy with the vehicles and transport we already have available.” Instead, he said automotive firms, industry and the Government are the driving forces behind CAV development.

 “I foresee a very slow evolution to CAVs rather than the revolution that many are talking about,” he added. “I actually think that flying cars is an easier problem to solve than autonomous vehicles on the road. Airspace is already regulated and people are quite happy to hand control of planes to machines.”

In addition he noted that flying cars would significantly reduce the need to build and maintain highways, and would not present the problem of integration with non-autonomous vehicles, as expected on the roads.

Arup’s infrastructure advisory director Alistair Hunter also questioned whether the public genuinely wants autonomous vehicles. But he said: “I struggle a bit with the flying car concept, not simply because of the prospect of the safety case associated with it but also the actual physics of it. You will need so much energy to fly these vehicles.”

He added that economics will ultimately dictate whether the UK sees widespread adoption of road going CAVs. “If the technology is there and the regulatory regime opens up to the point where you can travel conveniently and cheaply using a Mobility as a Service model with CAVs, I think there will be large scale adoption.”

WSP director Rachel Skinner told the event that there is “absolutely” a business case for CAVs. “Congestion and road accidents each cost us upwards of £30Bn a year in the UK. Then once you build in some of the social and environmental benefits I think there is a staggeringly great business case. The trick is how you bring that business case together in the right way.”

She called on the public sector to show more leadership in thinking about “what is it that we really want”, in order to help relevant solutions to come forward. “We risk missed opportunities if we don’t get that leadership part right,” she said.

Photograph: Aeromobil