Driverless cars can kill energy saving goals: Researchers

Driverless vehicles can intensify car use, reducing or even eliminating promised energy savings and environmental benefits in the near future, a study led by a University of Leeds researcher has warned.

Development of autonomous driving systems has accelerated rapidly since the unveiling of Google's driverless car in 2012. However, new research suggests its actual impact may be complicated by how the technology changes our relationship with our cars.

"There is no doubt that vehicle automation offers several efficiency benefits, but if you can work, relax and even hold a meeting in your car, that changes how you use it," said lead study author Dr Zia Wadud, associate professor at the University of Leeds.

"That, in turn, may change the transport equation and the energy and environmental impact of road transport," he noted.

The study uses analysis of self-driving technology combined with data on car and truck use, driver licences, and vehicle running costs to model the impact on energy demand of various levels of automation on US roads by 2050.

It estimates a five percent to 60 percent increase in car energy consumption due to people choosing to use highly automated cars in situations where they would have previously taken alternative transport.

"When you make a decision about transport, you don't just think about the out-of-pocket costs of the train ticket or the car's petrol; you also take into account non-financial costs," explained Dr Wadud in a paper published in the journal Transportation Research Part A.

Car owners might choose to travel by train to relatively distant business meetings because the train allows them to work and relax. But if you can relax in your car as it safely drives itself to a meeting in another city that changes the whole equation.

The study also predicts that people who currently find it difficult or impossible to drive will have increased access to road transport with the advent of the new systems - resulting in an estimated two percent to 10 percent increase in road energy use for personal travel.

"There is lots of hype around self-driving cars, much of it somewhat utopian in nature. But there are likely to be positives and negatives," added study co-author Don MacKenzie, assistant professor of civil and environmental engineering at the University of Washington.

The researchers warn that, if a high level of automation becomes the norm, it may be necessary to financially intervene in transport decisions.

For example, self-driving cars' navigation and communication systems could be used as a basis for road pricing schemes to control congestion and reduce overall travel demand, they said.