What Just Happened? Exploring Drivers’ Behaviour in Response to Minimal Risk Condition – A Qualitative Driving Simulator Study

Cortez, Diego; Large, David; Burnett, Gary

Abstract

Automated vehicles (AVs) are expected to improve road safety by reducing the number of collisions and safety critical events [1,2]. In the event of a failure of the automated driving system (ADS), or if it reaches the limit of its capability, action is required to preserve the safety of the vehicle occupants and other road users. The Society of Automotive Engineers (SAE) [3] highlights the need for the user to assume control in these situations by performing the driving task or placing the vehicle in a safe state, i.e. one in which the risk of a collision is reduced (‘minimal risk condition’ (MRC)). Should the driver not be available or deemed unable to achieve this (for example, if they are inattentive or distracted by a non driving-related task (NDRT)), the ADS (operating at level 4 or above) must achieve the MRC. MRC is therefore the subject of intense scrutiny, with many automotive manufacturing companies (OEMs) already proposing solutions, for example, by performing a controlled stop of the car at the side of the road (a ‘minimal risk manoeuvre’ (MRM)). This is arguably an extension of existing advanced emergency braking systems (AEBS) that sense driver inactivity or their lack of an adequate braking response and intervene. However, one of the key differences in a L4-AV is that drivers are “out of the loop” by design (i.e. not driving and engaged in a NDRT), and the MRM may therefore be entirely unexpected. As such, drivers’ responses and behaviour are unpredictable. For example, the ADS will likely prohibit driver intervention during the MRM [3], but it is unclear whether the driver would expect or attempt to intervene and what the consequences might be. These factors are likely to influence the acceptability of proposed solutions.

• Conference Name: 7th International Conference on Driver Distraction and Inattention (DDI2021)
• Conference Location: Lyon, France
• Start Date: Oct 18, 2021
• End Date: Oct 20, 2021
• Acceptance Date: Jul 15, 2020
• Publication Date: Oct 18, 2021
• Deposit Date: Feb 18, 2022
• Publicly Available Date: Feb 22, 2022
• Keywords: Automated Driving, Driving Simulator, Minimal Risk Condition
• Public URL: https://nottingham-repository.worktribe.com/output/7474101
• Related Public URLs: https://ddi2020.sciencesconf.org/