Transport collection

The human side of autonomous driving

Article collection features the latest research

Self-driving cars are no longer in the realm of science fiction. While we might not all be cruising the streets reading magazines behind the wheel just yet, the average car has moved through a few levels of automation already, and technology and policy are continuing to evolve.

According to the SAE, there are six levels of automation, ranging from no automation (level 0) to full automation (level 5). Most modern cars have reached partial automation (level 2), which involves the driver having their hands on the wheel and eyes on the road but use features like adaptive cruise control. Taking the step to level three means putting the system in control of monitoring the driving environment; the human driver only needs to jump in occasionally.

But regardless of the level of automation we reach, there will always be a human side to autonomous driving, whether it’s the psychology behind getting people into self-driving cars, the interaction between car and human or the policy implications of the technology. In this collection, you can read some of the latest research on the human side of autonomous driving.


Perception

One of the big challenges will be getting people to step into self-driving cars in the first place, so it’s important to understand people’s perceptions of autonomous vehicles – not just drivers but also other road users.

In their paper in Safety Science, researchers from the University of Greenwich in the UK surveyed nearly 1,000 people on their perceptions of safety and their acceptance of autonomous vehicles. They found that overall, people perceive autonomous cars as a “somewhat low risk” form of transport and have little opposition to their use on public roads.

Opinions differed depending on the person’s perspective: passengers perceived automated cars to be riskier than did pedestrians. Gender and age also had an impact: men and younger adults showed greater acceptance of the technology. The researchers point out that future studies should continue to look at perception taking perspective into account, concluding: “it would appear that the idea of autonomous cars on public roads has already found acceptance amongst many people. However, further findings highlight that much effort is still required to encourage widespread acceptance.”

The information people are exposed to – particularly in the media – is already having an influence on acceptance. In two studies, researchers at Embry-Riddle Aeronautical University in the US investigated the effect of positive and negative information on people’s perceptions of automated vehicles. The results, published in Transport Policy, revealed that people are more willing to ride in self-driving cars after hearing positive information about them, and less likely after hearing negative information. They also found that nationality plays a role: Indians were significantly more willing than Americans to ride in self-driving cars.

The researchers wrote: “Consumer perceptions will ultimately determine the success or failure of driverless vehicles, and potentially drive policy changes as driverless vehicles become more common.”


Practice

Regardless of how automated a vehicle is, there will always be a human element in its operation if a person is to ride in it. One key factor in the appropriate use of the technology is trust.

In their study in Applied Ergonomics, a team from the Technical University of Munich in Germany looked at the effect of information that promoted or lowered trust in the technology on participants’ reported trust, reliance on the technology and performance in taking over control of the vehicle. During a 17-minute drive on a highway in a level 3 automated car, 40 participants each encountered three situations: two of them were non-critical, so the driver could choose whether to take control of the car, and one required them to take control to avoid a crash. At the same time, they were all engaged in a non-driving related task – a visual task in which they had to identify one slightly larger circle on a screen of many others.

The results showed that people who reported a higher level of trust in the technology spent less time looking at the road and the instrument cluster and more time looking at the task. Those who had been exposed to trust-promoting information before the simulation were between 3.65 and 5 times more likely to intervene in the non-critical situations than those in the trust lowering group. The people in the trust promoted group were more likely to crash in the critical situation: this group had six collisions, compared to none in the lowered trust group.

While the technology impacts human behavior, the reverse is also true: researchers are modelling human behaviour to design technology. In their article in Transportation Research Part C: Emerging Technologies, a team at Texas A&M University and Ford Research Laboratories in the US present a game theory-based lane-changing model that mimics human behavior, particularly taking driver aggressiveness into account. The results show that “the game theory-based controller is capable of changing lanes in a human-like manner and outperforms fixed rule-based controllers.”


Policy

In addition to optimal technology and willing drivers, autonomous driving also needs to lean on a policy framework to be successful.

In their editorial to a new special issue of Transportation Research Part A: Policy and Practice on autonomous vehicle policy, guest editors Dr Marchau, Dr Zmud and Dr Kalra comment: “Transport policymakers in various countries are increasingly interested in the large-scale implementation of fully automous vehicles (AVs). However, policy development regarding AVs is hindered by large uncertainties related to their development and deployment, the contribution of such deployments to general transport policy goals, and societal constraints and conditions for AV deployment.”

One of the articles in this special issue gives policymakers research-based information to help them address some of the questions that remain, such as “Is it enough to simply modify current road and vehicle policies or will new policies need to be developed addressing much broader aspects of the transportation system?” The authors of the paper, from The American Center for Mobility and the US Army Research Laboratory, conclude:

“To date, policy has focused on ensuring technology performs reliably and is consistently applied across vehicles. Transportation systems, however, are social systems that are created and continually modified by the people who participate in them… As AVs begin participating in the transportation system alongside humans, policy must consider social norms and how humans communicate, reciprocate, and participate.”

So, will we soon see our highways full of cars driving their owners around while they read books or catch up on the latest TV series? Not necessarily, according to Prof. Juan de Dios Ortúzar, Emeritus Professor at Pontificia Universidad Catolica de Chile and Co-Editor-in-Chief of Transportation Research Part A: Policy and Practice:

“There is a debate hotting up among experts about the likelihood of having fully AVs operating in practice before 2030; work in the areas of artificial intelligence, big data and machine learning (which are key in AV deployment in practice) suggest that this will not happen for at least 20 to 30 years, contrary to many people’s expectations that AVs will be soon circulating in the streets,” he said.

“Another hot debate is related to insurance policies – who is responsible in the case of accidents, particularly if control can be turned back to the AV passenger in the event of a system malfunction? And a third is associated with a moral dilemma: that of the need to program the AV to potentially run over – and possibly kill – a pedestrian, say, to save the AV passenger in the unlikely event of an accident.”

All the while these debates are ongoing, we may not see the immediate proliferation of AVs some people are expecting, says Prof. Ortúzar.

All these are issues without a clear answer today, which justify the impressive amount of interest and research in this topic at present. I suspect this will continue for several years to come.


Read the collection

In this collection, you can find some of the latest research covering the human side of automated driving. You can read the collection here:

The effects of positive and negative information on consumers’ willingness to ride in a driverless vehicle,” Transport Policy, Available online 7 April 2018

Psychosocial factors associated with intended use of automated vehicles: A simulated driving study,” Accident Analysis and Prevention

Autonomous vehicles’ disengagements: Trends, triggers, and regulatory limitations,” Accident Analysis and Prevention

Introduction matters: Manipulating trust in automation and reliance in automated driving,” Applied Ergonomics

Perceptions of autonomous vehicles: Relationships with road users, risk, gender and age,” Safety Science

It takes two to Tango: Automated vehicles and human beings do the dance of driving – Four social considerations for policy,” Transportation Research Part A: Policy and Practice

Does context matter? A comparative study modelling autonomous vehicle impact on travel behaviour for Germany and the USA,” Transportation Research Part A: Policy and Practice

Autonomous driving, the built environment and policy implications,” Transportation Research Part A: Policy and Practice

Designing parking facilities for autonomous vehicles,” Transportation Research Part B: Methodological

The impact of private autonomous vehicles on vehicle ownership and unoccupied VMT generation,” Transportation Research Part C: Emerging Technologies

A human-like game theory-based controller for automatic lane changing,Transportation Research Part C: Emerging Technologies

Carrot and stick: A game-theoretic approach to motivate cooperative driving through social interaction,” Transportation Research Part C: Emerging Technologies

A qualitative examination of drivers’ responses to partially automated vehicles,” Transportation Research Part F: Traffic Psychology and Behaviour, Volume 56, July 2018, Pages 167-175

What influences the decision to use automated public transport? Using UTAUT to understand public acceptance of automated road transport systems,” Transportation Research Part F: Traffic Psychology and Behaviour, Volume 50, October 2017, Pages 55-64