Metacognition,rumination and road rage: An examination of driver anger progression and expression in Australia

Road rage is a serious issue impacting road safety on Australian roads. This study investigated the psychological antecedents involved in aggressive driver behaviours. Specifically, the study investigated the relationships between metacognitive beliefs, anger rumination, trait driver anger, and driver aggression; and examined the extent of aggressive behaviours in a sample of Australian drivers (N = 246). An inspection of cross-tabulations indicated that nearly all drivers engaged in verbal driver aggression (94%), approximately half of the drivers engaged in vehicle aggression (53%), and approximately a quarter of the drivers engaged in physical aggression (27%). Driver aggression was more commonly reported from males, open licensed, and middle-aged drivers. Structural path analysis indicated that there was a hierarchical series of relationships present, in that metacognitive beliefs influenced cognitive constructs such as anger rumination and constructive expression. Additionally, such factors were shown to more prominently influence trait driver anger, and the degree to which it was expressed. Bivariate correlations also demonstrated that the relationships carried forward to more specific dimensions of anger rumination and driver aggression styles. The findings of this study may assist to identify the origins of psychological mechanisms involved with anger progression and expression and inform potential interventions for aggressive driving behaviours.     

Impact on driver behaviour of guardrails of different height in horizontal-vertical coordinated road scenarios with a limited available sight distance

Drivers consider traffic barriers (e.g., guardrails) a protection system, a hard obstacle and a sight obstruction. Hence, the possibility of using containment level barriers which are higher and superior than the minimum required by current standards should be carefully evaluated. Moreover, research investigations into their impact on driver behaviour should be designed so as to distinguish between the effects associated with each of the three roles cited above.This driving simulation study investigates how drivers adapt their longitudinal and transversal behaviour when negotiating curves with guardrails of different heights on horizontal-vertical coordinated two–lane rural road settings, with consideration given solely to the sight obstruction effect of the guardrails. Fifty-four participants drove four out of the eighteen possible scenarios obtained when the same horizontal alignment is combined with three vertical profiles with three inner roadside treatments (no guardrails, 0.75 m two–wave and 0.95 m three-wave guardrails) and the two driving directions.Research outcomes confirm that guardrail height has a significant impact on lateral and longitudinal behaviour. With the minimum standard, i.e., the minimum height, drivers stay closer to the roadside, while higher guardrails result in drivers increasing their lateral distance. Speeds are influenced by the interaction between the guardrail and other geometric and human factors. Male and female drivers adapt differently to the limitation in the available sight distance caused by the guardrail: males increase their speed, adopting a more aggressive behaviour than females. Important safety implications due to the higher speeds and wider trajectories have to be considered at the design stage.     

Sexual behaviours among dyadic vehicle occupants

Sexual activity while driving is a risky behaviour frequently found across media. However, much is unknown about the practices and roles that dyadic occupants of vehicles (i.e. a driver and passenger) perform when engaging in sexual activity while driving. To cover this gap, a content analysis of sexually explicit media (SEM) was conducted on a sample of 208 videos taken from Pornhub.com. The videos portrayed a naturalistic driving situation of a driver of a moving vehicle engaging in sexual activity with a passenger. Videos were coded for sexual behaviours and characteristics of the vehicle occupants (gender and role). Drivers were generally male, while passengers were female. A range of sexual activities while driving were coded, including oral sex, unclothed and clothed masturbation, varying levels of nudity, and ejaculation. Drivers appear to be the focus of sexual attention, as they are generally the ones receiving sexual acts from the passenger, and predominantly ejaculating. Additionally, female passengers perform oral sex on drivers more often than male passengers, and female vehicle occupants tend to have greater levels of nudist exposure than males. This study highlights the complexities of sexual activity while driving and patterns for consideration when developing interventions.     

Effect of verbal messages with reminders to communicate driving situations to alter driver behavior in conditional driving automation

In conditionally automated driving, drivers are relieved of steering (hands-off), accelerating, and braking actions as well as of continuous monitoring of driving situations and the system operation status (eyes off). This enables continuously engagement in non-driving-related activities. Managing the allocation of a driver’s attention to the surrounding environment and automation status presents a major challenge in human–machine system design. In this study, we propose a verbal message with a reminder (monitoring request) to divert the driver’s attention from non-driving-related activities to peripheral monitoring under conditionally automated driving. When the system encounters events related to weather, traffic, and road geometry, it provides a verbal message pertaining to the road surroundings (e.g., “It is foggy outside”) to the driver. After three seconds, the system provides a reminder message (i.e., “Did you confirm it?”) to the driver. We explore two questions: (1) how does the message with the reminder affect the driver’s attention allocation, and (2) how does the message with the reminder affect the driver behavior in response to a request to intervene (RTI). With a driving simulator, we designed a repeated measures mixed design with a between-participant factor of “Driving condition” and within-participant factors of “Event type” and “Measurement time”. Three driving conditions were established as follows: no messages, messages without reminders, and messages with reminders. Twenty-seven drivers participated as participants in the driving simulator experiment. Results showed that the reminder message was effective in allocating the participants’ attention to the surrounding environment, and the participants took over the driving task after spending more time understanding the take-over situation in the condition of messages with reminders compared to those in the condition of no messages. We conclude that the proposed reminder message can direct drivers’ attention to the road surroundings during conditionally automated driving. In the future, we plan to design adaptive verbal monitoring requests to adjust the reminder message according to the situation.     

Assessing the effect of long-automated driving operation,repeated take-over requests,and driver’s characteristics on commercial motor vehicle drivers’ driving behavior and reaction time in highly automated vehicles

Automated Commercial Motor Vehicles (CMVs) have the potential to reduce the occurrence of crashes, enhance traffic flow, and reduce the stress of driving to a larger extent. Since fully automated driving (SAE Level 5) is not yet available, automated driving systems cannot perform all driving tasks under all road conditions. Drivers need to regain the vehicle’s control when the system reaches its maximum operational capabilities. This transition from automated to manual is referred to as Take-Over Request (TOR). Evaluating driver’s performance after TORs and assessing effective parameters have gained much attention in recent years. However, few studies have addressed CMV drivers’ driving behavior after TOR and the effect of long-automated driving and repeated TORs. This paper aims to address this gap and gain behavioral insights into CMV drivers’ driving behavior after TOR and assess the effect of the duration of automated operation before TOR, repeated TORs, and driver characteristics (e.g., age, gender, education, and driving history). To accomplish this, we designed a 40-minutes experiment on a driving simulator and assessed the responses of certified CMV drivers to TORs. Drivers’ reaction time and driving behavior indices (e.g., acceleration, velocity, and headway) are compared to continuous manual driving to measure driving behavior differences. Results showed that CMV drivers’ driving behavior changes significantly after the transition to manual regardless of the number of TORs and the duration of automated driving. Findings suggest that 30 min of automated operation intensifies the effect of TOR on driving behaviors. In addition, repeated TOR improves reaction times to TOR and reduces drivers' maximum and minimum speed after TORs. Driver’s age and driving history showed significant effects on reaction time and some driving behavior indices. The findings of this paper provide valuable information to automotive companies and transportation planners on the nature of driver behavior changes due to the carryover effects of manual driving right after automated driving episodes in highly automated vehicles.     

Effect of chevron design on driver behaviour when encountering and passing through a dangerous curve

Horizontal curves are locations on the road network with a high road accident risk. In order to provide drivers with timely and proper information about the upcoming curve, road authorities often use chevron signs. Although the main design of chevrons is similar in most countries (one colour for the background and another for the arrow), the combination of colours differs. The aim of this simulator study is to investigate how different colour combinations affect drivers when they encounter and drive through horizontal curves on rural roads at daytime. Overall, each of the tested chevrons reduced the driving speed (between 25 and 29 km/h), although not to the speed limit level (60 km/h). However, for curves marked with chevrons with fluorescent or white background the driving speed was the lowest at all measuring points, regardless of the curve direction. The observation of lateral movement shows that there are no significant differences in the way the vehicle is positioned when approaching and driving through curves marked with different chevrons. Based on the obtained results, practical recommendations and potential future research activities are presented.     

Effect of motorcycle lighting configurations on drivers’ perceptions of closing during nighttime driving

ObjectiveThe aims were to better understand how drivers perceive an approaching set of motorcycle headlights during nighttime driving and to determine whether alternative motorcycle headlight configurations improve drivers’ perceptual judgments of closing for an oncoming motorcycle.BackgroundMotorcyclists account for a disproportionate number of roadway fatalities, especially at night. One potential cause of this is drivers’ misjudgments of a motorcycle’s approach.MethodThe first experiment examined whether drivers were more sensitive to horizontal or vertical optical expansion and whether drivers could integrate these two dimensions to achieve a lower looming threshold. A second experiment built on these results to test whether alternative headlight configurations that maximized size were better than other motorcycle headlight configurations and a car’s headlights. In both experiments, participants were instructed to press a button to indicate when they first perceived an oncoming vehicle to be closing under nighttime driving conditions.ResultsHeadlight orientation did not affect when drivers perceived closing, and drivers were not able to integrate optical expansion from multiple dimensions in a way that achieves a lower looming threshold. However, the alternative motorcycle headlight configurations that accentuated the full extent of a motorcycle’s size resulted in drivers perceiving closing sooner than other motorcycle headlight configurations but not sooner than a car.ConclusionDrivers perceive closing sooner for larger headlight configurations except when the headlight configurations are relatively small, in which case the effect of headlight size is attenuated.ApplicationDrivers’ perceptual judgments of motorcycles may improve when motorcycles have headlights that span its full height.     

Auditory and haptic systems for in-car speed management – A comparative real life study

Field experiments with ISA (intelligent speed adaptation) were carried out in Hungary and Spain in 2003 and 2004, respectively. Twenty private vehicles in each country were equipped with two kinds of systems: (1) support via an active accelerator pedal (AAP) and (2) warning via beep signals and a flashing red light when the speed limit was exceeded (BEEP). The test drivers drove for a month with both systems installed in each car. Speed was continually logged in all the vehicles and the test drivers were interviewed about their acceptance and experiences of the systems. The results show that both systems reduced the mean and 85 percentile speeds, but that the AAP was more effective. There was no long-lasting effect on speeds when the systems were removed. After the trial half of the drivers were willing to keep an ISA system, but more drivers wanted to keep the BEEP-system even though it showed lower satisfaction ratings than the AAP. The results indicate no major differences between the countries despite the workload being perceived to be higher in Hungary than in Spain.     

Modeling ratings of in-vehicle alerts to pedestrian by leveraging field operational tests data in a controlled laboratory study

We show how to leverage expensive field operational tests (FOT) data in a controlled laboratory study when defining an in-vehicle algorithm that alerts drivers to pedestrians. We used an empirical approach that quantifies the relative level with which drivers are likely to accept alerts to pedestrians. The approach was used in two studies to investigate a range of contextual factors known to influence driver ratings of alerts to pedestrians issued by a driver-assistance system. Regression analysis shows that four factors consisting of combinations of pedestrian location and motion relative to the road ahead of the vehicle explain 85% of the variability in drivers’ ratings of alerts. Adding two factors related to the uncertainty of the pedestrians’ future path improves the model slightly. These findings suggest that drivers’ assessment of the danger associated with pedestrians derives largely from the possibility that they might move into the vehicle’s path, even when the vehicle is not on a collision course with the pedestrians. The less probable such an event seems, the less accepted an alert will be. Time to arrival (TTA) improved the regression model only when restricted to pedestrians in clear need of an alert, but was also found to have an effect in alert timing. This finding suggests that four contextual factors largely define the perceptual cues that drivers use to rate alerts to pedestrians.     

Effects of driving anger on driver behavior – Results from naturalistic driving data

There is a positive relationship between driving anger and near-crash or crash risk. However, it remains unclear if anger in fact contributes to traffic accidents and whether this happens due to cognitive overload or aggressive driving behaviors. This study investigated how anger affects driving behavior based on naturalistic driving data from the second Strategic Highway Research Program (SHRP 2). Ten-minute trip segments were analyzed in which drivers exhibited anger with regard to driving errors, violations, and aggressive expressions. This data was compared to a matched baseline consisting of the same drivers not exhibiting anger. Results showed that anger resulted in more frequent aggressive driving behaviors but did not increase driving error frequency. Anger consequently creates danger due to deliberate behaviors rather than because of cognitive overload. In congruence with this finding, only anger triggered by threats, provocations, and frustrations increased the frequency of deliberate infringements. In contrast, anger due to having conflicts with someone on the phone or with a passenger was not linked to any type of aberrant driving behavior. Finally, severe displays of anger were accompanied by more violations as compared to slight or marked anger.