Predicting driver reaction time and deceleration: Comparison of perception-reaction thresholds and evidence accumulation framework

Effects of driver's braking behavior by the real-time pedestrian scale warning system

A driver warning system can improve pedestrian safety by providing drivers with alerts about potential hazards. Most driver warning systems have primarily focused on detecting the presence of pedestrians, without considering other factors, such as the pedestrian's gender and speed, and whether pedestrians are carrying luggage, that can affect driver braking behavior. Therefore, this study aims to investigate how driver braking behavior changes based on the information about the number of pedestrians in a crowd and examine if a developed warning system based on this information can induce safe braking behavior. For this purpose, an experiment scenario was conducted using a virtual reality-based driving simulator and an eye tracker. The collected driver data were analyzed using mixed ANOVA to derive meaningful conclusions. The research findings indicate that providing information about the number of pedestrians in a crowd has a positive impact on driver braking behavior, including deceleration, yielding intention, and attention. Particularly, It was found that in scenarios with a larger number of pedestrians, the Time to Collision (TTC) and distance to the crosswalk were increased by 12%, and the pupil diameter was increased by 9%. This research also verified the applicability of the proposed warning system in complex road environments, especially under conditions with poor visibility such as nighttime. The system was able to induce safe braking behavior even at night and exhibited consistent performance regardless of gender. In conclusion, considering various factors that influence driver behavior, this research provides a comprehensive understanding of the potential and effectiveness of a driver warning system based on information about the number of pedestrians in a crowd in complex road environments.

Negative mood mind wandering and unsafe driving in young male drivers

OBJECTIVE

Road traffic crash fatalities disproportionately affect young male drivers. Driver distraction is a leading contributor to crashes. Mind wandering (MW) is a prevalent form of driver distraction that is linked to certain unsafe driving behaviours that are associated with increased crash risk (e.g., faster driving). Negative mood can lead to MW, and thus may represent a causal pathway to MW-related unsafe driving. This preliminary pre-post (T1, T2), randomized, controlled, single-blinded experiment tested whether negative mood, compared to neutral mood, increases MW while driving as well as unsafe driving and emotional arousal during MW. It also tested the moderating contribution of trait rumination and inhibitory control to this proposed causal pathway.

METHODS

Forty healthy male drivers aged 20 to 24 were randomly allocated to a negative or neutral mood manipulation involving deception. Individual differences in trait rumination and inhibitory control were measured at T1. At T1 and T2, participants drove in a driving simulator measuring driving speed, headway distance, steering behaviour, and overtaking. Heart rate and thought probes during simulation measured emotional arousal and MW, respectively.

RESULTS

Negative mood exposure led to more MW while driving (Odds Ratio = 1.79, p = .022). Trait rumination positively moderated the relationship between negative mood and MW (Odds Ratio = 2.11, p = .002). Negative versus neutral mood exposure led to increases in headway variability (Cohen's d = 1.46, p = .026) and steering reversals (Rate Ratio = 1.33, p = .032) during MW relative to focused driving. Between-group differences in emotional arousal were not significant.

CONCLUSION

Results support a causal pathway from negative mood to unsafe driving via MW, including the moderating contribution of trait rumination. If replicated, these preliminary findings may inform the development of interventions targeting this potential crash-risk pathway in vulnerable young driver subgroups.

A novel hazard avoidance model based on young drivers' characteristics: A driving simulator study

This paper aims to examine the key factors influencing young drivers' hazard avoidance in Iran. In this study, a hazard avoidance index is defined and calculated for investigating the effect of impulsiveness, behavioral, and psychological characteristics on driving hazard avoidance. A questionnaire and go-no-go and flanker computer tests as well as a driving simulator are used for collecting data from 173 Iranian drivers under the age of 30. For this purpose, different scenarios were used, such as pedestrian crossing, the presence of fixed obstacles, and animals crossing the road, whose various characteristics are also changed. Structural equation modeling and the partial least squares method are applied for investigating the relationship between different variables and the hazard avoidance index. The results show that the driver hazard avoidance index is mostly affected by variables such as inhibitory control, opposite directional response, attentional impulsiveness, motion impulsiveness, non-planning impulsiveness, disregarding the law, and lapses and error. The results could help policymakers to assess diving hazard avoidance and improve training programs related to traffic safety based on the variables that are more effective on inexperienced and novice drivers' hazard avoidance.

The influence of freeway curve characteristics on drivers’ speed perception accuracy

Owing to the complicated geometric conditions and increasingly diversified driving environment, freeway curves have become a road section with frequent serious accidents. To ensure safe driving on curves, drivers must first perceive the movement condition and the vehicle’s position, and accurately evaluate the characteristics of the road to make the right speed choice. In this process, the perception of speed plays a crucial role. The present study aims to investigate the driver’s speed perception characteristics with respect to freeway curves to better understand the driver speed selection mechanism. We first construct six three-dimensional (3D) virtual highway models, which are consistent with the geometric lines and traffic engineering instruments of real freeways. A virtual simulation test is then conducted in a highly immersive environment. After the completion of the simulation experiment, we conduct a field verification experiment, test the actual driving speed and perceived speed of drivers in the same place as the simulation experiment, and verify the effectiveness of the simulation method. Finally, 25 3D curve models of four different types are constructed, and the influence of curve characteristics (e.g., curve radius, curve combination, tangent length between curves) on drivers’ speed perception accuracy are tested on the simulation platform. The results show that the driver’s perceived speed is lower than the real speed when driving on curves, and the tangent-to-spiral (TS) point is the section where the driver’s speed is most underestimated. Radius was the most important factor affecting driver’s speed perception, but the tangent length between curves also had a lesser influence. However, the curve combination had no effect on it. Our findings can help researchers and road designers understand the reasons for drivers’ speed choice, thus promoting drivers’ safety on freeway curves.