Enthusiasm for driverless cars

In pre-Budget briefing, the Chancellor expressed enthusiasm for government investment to help get driverless cars on UK roads by 2021. In this he followed the example of his predecessor, George Osborne, who was keen that Britain takes bold decisions to ensure that it leads the world in new technologies and infrastructure. The Budget was followed by the launch of the Government’s Industrial Strategy, which featured new modes of mobility as one of four Grand Challenges, and stated that the Government wants to see fully self-driving cars, without a human operator, on UK roads by 2021.

There are two related reasons why the Government might attempt to ‘pick a winner’ of this kind: industrial policy and transport policy. If, as George Osborne claimed, driverless cars represent ‘the most fundamental change to transport since the invention of the internal combustion engine’, then support for autonomous vehicles should form part of our industrial strategy as well as our transport policy.

The Government has indeed been active in supporting trials and future deployment of driverless vehicles on British roads. Projects are underway in Bristol, Coventry, Greenwich and Milton Keynes; R&D is being funded; Codes of Practice for on-road testing published; and legislation introduced in Parliament to ensure that vehicle insurance covers both the motorist when driving as well as the car in automated mode.

There are two routes to driverless vehicles. The evolutionary approach, pursued by all the main international auto manufacturers, offers to relieve drivers of tedious tasks, for instance by means of adaptive cruise control, which regulates the speed and space to the vehicle ahead. The revolutionary route, pioneered by Google (now branded Waymo), dispenses with the driver entirely. Other US businesses with disruptive approaches are active developing driverless technologies, including Tesla and Uber.

With the enormous worldwide effort underway, it is going to be difficult for the UK projects to make much impact – unless they have some breakthrough technologies under test, of which there is no public evidence. Nevertheless, Government support for driverless vehicles might be justified if the impact on the transport system were clearly beneficial.

Transport benefits

Autonomous vehicles would need to be demonstrably safer than their human-driven counterparts to be publicly acceptable. This should be achievable, given that most crashes are caused by human error. So we may expect a safety benefit from driverless cars, and lower insurance costs. Beyond that, it seems likely that there will be two main impacts.

First, replacing the human driver with a robot would lessen the cost of licensed taxis and private hire vehicles, enhancing their competitiveness, which is why Uber is so keen on this technology. Such robotic vehicles would fill the present gap in service provision that exists between high-capacity, low cost public transport and low-capacity, high cost taxis.

Proponents of public transport are anxious lest demand for efficient high-occupancy buses  is reduced. On the other hand, the ready availability of robotic taxis would reduce the attractions of individually owned cars, and robotic shared-use minibuses would allow door-to-door conveyance at reasonable charges. So we can envisage a future in which the availability of shared-use autonomous vehicles fosters a shift away from private ownership in urban centres, with a beneficial impact on traffic congestion.

Second, private ownership is likely to remain popular in suburbs and beyond. Driverless cars will allow new options, for instance sending the vehicle home unoccupied, after delivering the occupant to their workplace, for use by others in the household. This could reduce car ownership per household, but would increase vehicle-miles travelled. Another option would be ‘parking on the move’ – programming your car to cruise round the block while you do your shopping. However, such unoccupied vehicles would add to traffic and worsen congestion in urban areas, so would need to be regulated, to give priority to occupied vehicles.

The main problem of the transport system is road traffic congestion. The test for any new technology is its likely impact on congestion. For autonomous vehicles, there are many possible impacts, both positive and negative. In the absence of evidence from deployment at scale, the outcome is uncertain. So the transport policy case for support for driverless vehicles remains unclear. Yet that lack of clarity justifies cautious support of development, testing and deployment, to understand better the implications of what could yet turn out to be an important innovation.

Traditional transport technologies based on mechanical and civil engineering develop quite slowly. In contrast, digital technologies are fast and disruptive. Autonomous vehicles are where the digital hare has to ride on the back of the mechanical tortoise, with as yet uncertain consequences for the speed of travel.

A version of this blog appeared in The Conversation on 21 November 2017.