Timing of early warning stages in a multi stage collision warning system: Drivers’ evaluation depending on situational influences

“…The first stage is designed to increase the drivers’ attention and shift their attention toward the situation without immediate actions. The second stage requires drivers to take actual maneuvers ( Rhede et al, 2011 ; Werneke et al, 2014 ; Winkler et al, 2016 ). Some previous studies have investigated the effectiveness of the two-stage warning systems in the takeover process.…”

Section: Related Workmentioning

confidence: 99%

Optimal Time Intervals in Two-Stage Takeover Warning Systems With Insight Into the Drivers’ Neuroticism Personality

et al. 2021

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Conditional automated driving [level 3, Society of Automotive Engineers (SAE)] requires drivers to take over the vehicle when an automated system’s failure occurs or is about to leave its operational design domain. Two-stage warning systems, which warn drivers in two steps, can be a promising method to guide drivers in preparing for the takeover. However, the proper time intervals of two-stage warning systems that allow drivers with different personalities to prepare for the takeover remain unclear. This study explored the optimal time intervals of two-stage warning systems with insights into the drivers’ neuroticism personality. A total of 32 drivers were distributed into two groups according to their self-ratings in neuroticism (high vs. low). Each driver experienced takeover under the two-stage warning systems with four time intervals (i.e., 3, 5, 7, and 9 s). The takeover performance (i.e., hands-on-steering-wheel time, takeover time, and maximum resulting acceleration) and subjective opinions (i.e., appropriateness and usefulness) for time intervals and situation awareness (SA) were recorded. The results showed that drivers in the 5-s time interval had the best takeover preparation (fast hands-on steering wheel responses and sufficient SA). Furthermore, both the 5- and 7-s time intervals resulted in more rapid takeover reactions and were rated more appropriate and useful than the 3- and 9-s time intervals. In terms of personality, drivers with high neuroticism tended to take over immediately after receiving takeover messages, at the cost of SA deficiency. In contrast, drivers with low neuroticism responded safely by judging whether they gained enough SA. We concluded that the 5-s time interval was optimal for drivers in two-stage takeover warning systems. When considering personality, drivers with low neuroticism had no strict requirements for time intervals. However, the extended time intervals were favorable for drivers with high neuroticism in developing SA. The present findings have reference implications for designers and engineers to set the time intervals of two-stage warning systems according to the neuroticism personality of drivers.

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“…In addition, the formula used by McGehee et al (2002) depends on the performance of the sensor response and the reaction time needed for the driver to take an evasive maneuver; that is, not considering driver acceptance levels. In Winkler et al (2016), the time of the warnings was selected by the drivers. Winkler et al (2016) presented 2-stage warnings for slowmoving traffic.…”

Section: Introductionmentioning

confidence: 99%

“…In Winkler et al (2016), the time of the warnings was selected by the drivers. Winkler et al (2016) presented 2-stage warnings for slowmoving traffic. Each stage had multiple warnings and participants had to choose the best timing.…”

Section: Introductionmentioning

confidence: 99%

Forward collision warning based on a driver model to increase drivers’ acceptance

Guillen

Gohl

2019

Traffic Injury Prevention

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Objective: Systems that can warn the driver of a possible collision with a vulnerable road user (VRU) have significant safety benefits. However, incorrect warning times can have adverse effects on the driver. If the warning is too late, drivers might not be able to react; if the warning is too early, drivers can become annoyed and might turn off the system. Currently, there are no methods to determine the right timing for a warning to achieve high effectiveness and acceptance by the driver. This study aims to validate a driver model as the basis for selecting appropriate warning times. The timing of the forward collision warnings (FCWs) selected for the current study was based on the comfort boundary (CB) model developed during a previous project, which describes the moment a driver would brake. Drivers' acceptance toward these warnings was analyzed. The present study was conducted as part of the European research project PROSPECT ("Proactive Safety for Pedestrians and Cyclists"). Methods: Two warnings were selected: One inside the CB and one outside the CB. The scenario tested was a cyclist crossing scenario with time to arrival (TTA) of 4 s (it takes the cyclist 4 s to reach the intersection). The timing of the warning inside the CB was at a time to collision (TTC) of 2.6 s (asymptotic value of the model at TTA ¼ 4 s) and the warning outside the CB was at TTC ¼ 1.7 s (below the lower 95% value at TTA ¼ 4 s). Thirty-one participants took part in the test track study (between-subjects design where warning time was the independent variable). Participants were informed that they could brake any moment after the warning was issued. After the experiment, participants completed an acceptance survey. Results: Participants reacted faster to the warning outside the CB compared to the warning inside the CB. This confirms that the CB model represents the criticality felt by the driver. Participants also rated the warning inside the CB as more disturbing, and they had a higher acceptance of the system with the warning outside the CB. The above results confirm the possibility of developing wellsaccepted warnings based on driver models. Conclusions: Similar to other studies' results, drivers prefer warning times that compare with their driving behavior. It is important to consider that the study tested only one scenario. In addition, in this study, participants were aware of the appearance of the cyclist and the warning. A further investigation should be conducted to determine the acceptance of distracted drivers. ARTICLE HISTORY

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Timing of early warning stages in a multi stage collision warning system: Drivers’ evaluation depending on situational influences

Cited by 55 publications

References 23 publications

Investigation of a DSRC‐based end of queue collision warning system by considering real freeway data

Investigation of a DSRC‐based end of queue collision warning system by considering real freeway data

Optimal Time Intervals in Two-Stage Takeover Warning Systems With Insight Into the Drivers’ Neuroticism Personality

Forward collision warning based on a driver model to increase drivers’ acceptance

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