Investigating human factors of automated driving

Abstract

Autonomous vehicles have become a reality. This novel form of transport is expected to enhance road safety, provide comfort for drivers and decrease traffic problems. From a human factors’ perspective, however, this advanced technology can give rise to negative effects. Considerable human factors’ research on automated driving has already been undertaken on issues such as loss of situation awareness, vigilance decrement, suboptimal mental workload, over trust, distrust and acceptance of automated driving systems. Nevertheless several gaps still remain, particularly, how people in different age spectrum consider this novel technology?: what is the main factor to predict acceptance of the technology?: and how can the transition between automated and manual driving be managed safely in ways that drivers find acceptable?. To answer these empirical questions, four detailed studies were performed: i) public opinion; ii) factors influencing users’ acceptance; iii) the impact of control transition between automated and manual driving on drivers’ mental workload and driving performance; and iv) appropriate strategies to deal with system failure. To specifically answer those initial research questions and achieve the accurate results, the whole research process has been undertaken in four individual studies, using various research designs and methods of data collection (focus groups, a survey and two experiments using a driving simulator) in order to address these gaps in existing research. The specific research questions and objectives are pointed out in individual studies. Results of the focus group study revealed the different opinions toward autonomous driving and provided suggestions to develop the technology in the future. Key among these were the participants cited almost equal numbers of positive and negative opinions on the technology. Older people favoured automated driving technology more than others and younger people considered more negative opinions than other groups. Moreover, various options of autonomy, specific software for people with a disability or older people and ease of use were pointed out for the system development. Findings from the survey presented factors that predict users’ intention to use autonomous driving. The predictive models between the U.K and Thailand are different. In addition, the participants from Thailand were willing to use highly automated driving than the U.K.’s participants. The results of the focus group and survey also revealed that people were concerned about the technology especially when the system failure. Thus, the first driving simulator study was conducted to investigate the effects of control transition between automated and manual driving. The findings found the negative effects of transition control between automated and manual driving on drivers’ mental overload and driving performance degradation. Finally, the second driving simulator study reported the situation criticality and difficulty when the driver took over control from automated driving. It found that the autonomous system bringing the vehicle to a controlled stop is an appropriate strategy when the autonomous system fails. These main findings have important implications for consideration by technology makers and designers when designing automated vehicles. For example, at present, the dominant strategy in the case of automation failures is to hand back control to the driver. The results of this research suggest that the vehicle should bring itself to a controlled stop.