Abstract
We investigated after effects of automation in take-over scenarios in a high-end moving-base driving simulator. Drivers performed evasive manoeuvres encountering a blocked lane in highway driving. We compared the performance of drivers 1) during manual driving, 2) after automated driving with eyes on the road while performing the cognitively demanding n-back task, and 3) after automated driving with eyes off the road performing the visually demanding SuRT task.Both minimum time to collision (TTC) and minimum clearance towards the obstacle disclosed a substantial number of near miss events and are regarded as valuable surrogate safety metrics in evasive manoeuvres. TTC proved highly sensitive to the applied definition of colliding paths, and we prefer robust solutions using lane position while disregarding heading. The extended time to collision (ETTC) which takes into account acceleration was close to the more robust conventional TTC.In line with other publications, the initial steering or braking intervention was delayed after using automation compared to manual driving. This resulted in lower TTC values and stronger steering and braking actions. Using automation, effects of cognitive distraction were similar to visual distraction for the intervention time with effects on the surrogate safety metric TTC being larger with visual distraction. However the precision of the evasive manoeuvres was hardly affected with a similar clearance towards the obstacle, similar overshoots and similar excursions to the hard shoulder.Further research is needed to validate and complement the current simulator based results with human behaviour in real world driving conditions. Experiments with real vehicles can disclose possible systematic differences in behaviour, and naturalistic data can serve to validate surrogate safety measures like TTC and obstacle clearance in evasive manoeuvres.
Highlights
Vehicles with increasing levels of automation will allow drivers to delegate longitudinal and lateral control, to take their eyes off the road and engage in activities unrelated to driving (SAE J3016, 2016)
We focussed on SAE level 3 automation defined as “The sustained and operational design domain (ODD) specific performance by an automated driving system (ADS) of the entire dynamic driving task (DDT) with the expectation that the DDT fallback-ready user is receptive to ADS-issued requests to intervene, as well as to DDT performance-relevant system failures in other vehicle systems, and will respond appropriately” (SAE J3016, 2016)
In order to capture the criticality of evasive manoeuvres we evaluated four time to collision (TTC) metrics, clearance towards the obstacle and the road side, two overshoot metrics, and peak accelerations
Summary
Vehicles with increasing levels of automation will allow drivers to delegate longitudinal and lateral control, to take their eyes off the road and engage in activities unrelated to driving (SAE J3016, 2016). Drivers will have to resume manual driving in conditions not yet supported by automation such as complex urban traffic and adverse weather. Transitions between manual driving and various levels of automation can be initiated by the driver while in other cases the automation will take the initiative and will request the driver to resume control (Lu et al, 2016). Extensive experimental research on TOR has shown that after using automation, drivers need a sufficient time budget to generate effective control actions We define the available time budget as the time between the TOR or an equivalent stimulus in manual driving and the moment when an accident would occur when the driver would take no action. The time budget captures the time available for perception and rebuilding of situation awareness, response selection and response execution
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
