Anger-congruent behaviour transfers across driving situations

Anger and aggression on the road may sometimes appear unprovoked and unrelated to current driving circumstances. It is unclear whether such anger and aggression arises because of events prior to those circumstances in which anger is experienced and aggression is exhibited. In this study, time pressure and enforced following of a slowly moving vehicle were used to increase drivers' anger in order to assess whether affect and behaviour during a subsequent, non-provocative, drive would change accordingly. Ninety-six drivers drove twice in a simulated urban environment. During the first drive, oncoming traffic and a slowly moving lead vehicle required that half of the drivers travelled far slower than they would choose. During the second drive, drivers again followed slower vehicles and were required to respond to traffic events not encountered in the manipulation drive. Mood (Profile of Mood States) was assessed before and after each drive, and anger evaluations, arousal (heart rate) and behaviour (speed, lane position and collisions) were measured during drives. Anger increased and both mood and driving behaviour deteriorated in drivers exposed to slower lead vehicles, compared with control group drivers. These behavioural differences of speed and lane positioning carried over into the subsequent drive even to driving situations unlike those where provocation had previously occurred. Drivers who had previously been impeded later approached hazards with less caution, and attempted more dangerous overtaking manoeuvres. It is concluded that sometimes dangerous driving may result from anger provoked by circumstances other than those in which the behaviour is exhibited.     

Drivers Display Anger‐Congruent Attention to Potential Traffic Hazards

Previous research has suggested that angry drivers may respond differently to potential hazards. This study replicates and extends these findings. Under simulated driving conditions, two groups of drivers experienced conditions that would either increase angry mood (N = 12; men = 6) or not (control group, N = 12; men = 6). All drivers then performed a neutral drive, during which they encountered a number of traffic events not experienced in the initial drive. These included vehicles emerging from driveways into their path and jaywalking pedestrians. Subjective anger, eye‐movement behaviour and driving behaviours (speed and reaction times) were measured as drivers drove. Subjective moods (Profile of Mood States) were assessed before and after each drive. Anger‐provoked drivers reported reliably higher increases in angry mood when compared with the control group after the initial drive, and these increases remained stable across the subsequent neutral drive. During the neutral drive, anger‐provoked drivers demonstrated evidence of more heuristic style processing of potential hazards, with shorter initial gazes at less apparent hazards and longer latencies to look back at jaywalking pedestrians obscured by parked vehicles. Anger‐provoked drivers also took longer to make corrective actions to avoid potential collisions. It is concluded that anger‐provoked drivers may initially make more superficial assessments of certain driving situations and consequently underestimate the inherent risk. Copyright © 2012 John Wiley & Sons, Ltd.     

Who’s more angry? Comparing driver anger and aggression within work and personal driving contexts

Anger and driver aggression increase crash risk. However, how these manifest according to the purpose of the journey (work vs personal) and the unique relationships between sources of anger and aggressive expressions of that anger is under-researched. The current study examined the relationships between different types of anger and aggression, recent crashes and infringements between drivers who drive mainly for work with those who drive mainly for personal reasons.Participants (N = 630) completed an online questionnaire reporting their driving anger tendencies across situations of travel delays, danger and hostility from others, frequency of aggressive driving (using the vehicle, verbal or physical) and crash and infringements in the previous year. Drivers were classified as work or personal drivers based on the percentage of the time they drove for each reason. Relationships between anger sources and aggression types were examined using Structural Equation Modelling, comparing models between the two groups. The relationships between aggression and safety outcomes were explored using Mann-Whitney U tests.The relationships between anger and aggression were similar across work and personal drivers. However, some group differences in the situations that contributed to anger and aggression were identified. Aggression was more frequent for drivers who drove mainly for work and had received a traffic violation, compared to those who had not received a traffic violation.These findings can inform the development of targeted interventions to manage the triggers of anger and aggression. Interventions are likely to impact work and personal drivers; thus, could target employers and road transport authorities.     

Psychometric adaptation of the driving anger expression inventory in a Chinese sample

The purpose of this study was to assess the psychometric properties and the factorial structure of the Driving Anger Expression Inventory (DAX) in a Chinese sample. We also explored the relationships among driving anger expression, general anger expression, and driving outcomes. Three hundred and fifty-eight drivers completed the Chinese version of the DAX, the Anger Expression Scale (AX), the Dula Dangerous Driving Index (DDDI) and a questionnaire about several types of traffic violations. A confirmatory factor analysis of the Chinese DAX yielded a four-factor solution with 20 items. This solution showed the best goodness of fit of the data and acceptable reliability. The validity of the revised DAX was also verified. The aggressive expression forms were positively correlated with dangerous driving behaviors. Using the vehicle to express anger was associated with fines. The aggressive forms were also positively correlated with general anger expression-out and negatively correlated with general anger control. The adaptive expression of anger was positively correlated with anger control but negatively correlated with dangerous driving behaviors, penalty points and fines. Furthermore, young drivers (<30 years old) reported more personal and physical aggressive expressions of anger than other drivers. Gender differences were only found in some age groups. Thus, the revised DAX was confirmed to be a reliable and valuable instrument to measure forms of driving anger expression in traffic environments in China.     

A matter of style? Driver attributional ‘style’ in accounting for the driving of others as protective or as predisposing drivers towards retaliatory aggressive driving

Driver cognitions about aggressive driving of others are potentially important to the development of evidence-based interventions. Previous research has suggested that perceptions that other drivers are intentionally aggressive may influence recipient driver anger and subsequent aggressive responses. Accordingly, recent research on aggressive driving has attempted to distinguish between intentional and unintentional motives in relation to problem driving behaviours. This study assessed driver cognitive responses to common potentially provocative hypothetical driving scenarios to explore the role of attributions in driver aggression. A convenience sample of 315 general drivers 16–64 yrs (M = 34) completed a survey measuring trait aggression (Aggression Questionnaire AQ), driving anger (Driving Anger Scale, DAS), and a proxy measure of aggressive driving behaviour (Australian Propensity for Angry Driving AusPADS). Purpose designed items asked for drivers’ ‘most likely’ thought in response to AusPADS scenarios. Response options were equivalent to causal attributions about the other driver. Patterns in endorsements of attribution responses to the scenarios suggested that drivers tended to adopt a particular perception of the driving of others regardless of the depicted circumstances: a driving attributional style. No gender or age differences were found for attributional style. Significant differences were detected between attributional styles for driving anger and endorsement of aggressive responses to driving situations. Drivers who attributed the on-road event to the other being an incompetent or dangerous driver had significantly higher driving anger scores and endorsed significantly more aggressive driving responses than those drivers who attributed other driver’s behaviour to mistakes. In contrast, drivers who gave others the ‘benefit of the doubt’ endorsed significantly less aggressive driving responses than either of these other two groups, suggesting that this style is protective.     

A driving simulator study to assess driver performance during a car-following maneuver after switching from automated control to manual control

A review of the literature on autonomous vehicles has shown that they offer several benefits, such as reducing traffic congestion and emissions, and improving transport accessibility. Until the highest level of automation is achieved, humans will remain an important integral of the driving cycle, which necessitates to fully understand their role in automated driving. A difficult research topic involves an understanding of whether a period of automated driving is likely to reduce driver fatigue rather than increase the risk of distraction, particularly when drivers are involved in a secondary task while driving. The main aim of this research comprises assessing the effects of an automation period on drivers, in terms of driving performance and safety implications. A specific focus is set on the car-following maneuver. A driving simulator experiment has been designed for this purpose. In particular, each participant was requested to submit to a virtual scenario twice, with level-three driving automation: one drive consisting of Full Manual Control Mode (FM); the other comprising an Automated Control Mode (AM) activated in the midst of the scenario. During the automation mode, the drivers were asked to watch a movie on a tablet inside the vehicle. When the drivers had to take control of the vehicle, two car-following maneuvers were planned, by simulating a slow-moving vehicle in the right lane in the meanwhile a platoon of vehicles in the overtaking lane discouraged the passing maneuver. Various driving performances (speeds, accelerations, etc.) and surrogate safety measures (PET and TTC) were collected and analysed, focusing on car-following maneuvers. The overall results indicated a more dangerous behavior of drivers who were previously subjected to driving automation; the percentage of drivers who did not apply the brakes and headed into the overtaking lane despite the presence of a platoon of fast-moving vehicles with unsafe gaps between them was higher in AM drive than in FM drive. Conversely, for drivers who preferred to brake, it was noted that those who had already experienced automated driving, adopted a more careful behavior during the braking maneuver to avoid a collision. Finally, with regard to drivers who had decided to overtake the braking vehicle, it should be noted that drivers who had already experienced automated driving did not change their behavior whilst overtaking the stopped lead vehicle.     

The impact of a dedicated lane for connected and automated vehicles on the behaviour of drivers of manual vehicles

Connected and automated vehicles (CAVs) are expected to enhance traffic efficiency by driving at shorter time headways, and traffic safety by shorter reaction times. However, one of the main concerns regarding their deployment is the mixed traffic situation, in which CAVs and manually driven vehicles (MVs) share the same road.This study investigates the behavioural adaptation of MV drivers in car-following and lane changing behaviour when they drive next to a dedicated lane (DL) for CAVs and compares that to a mixed traffic situation. The expectation is that in a mixed traffic situation, the behavioural adaptation of MV drivers is negligible due to lower exposure time and scarce platoons, while concentrating the CAVs on one dedicated lane may cause significant behavioural adaptation of MV drivers due to a higher exposure time and conspicuity of CAV platoons.Fifty-one participants were asked to drive an MV on a 3-lane motorway in three different traffic scenarios, in a fixed-base driving simulator: (1) Base, only MVs were present in traffic, (2) Mixed, platoons of 2–3 CAVs driving on any lane and mixed with MVs, (3) DL, platoons of 2–3 CAVs driving only on a DL. The DL was recognizable by road signs and a buffer demarcation which separated the DL from the other lanes. A moderate penetration rate of 43% was assumed for CAVs.During the drives, the car following headways and the accepted merging gaps by participants were collected and used for comparisons of driving behaviour in different scenarios.Based on the results, we conclude that there is no significant difference in the driving behaviour between Base and Mixed scenarios at tested penetration rate, confirming our research expectation. However, in DL scenario, MV drivers drove closer to their leaders specially when driving on the middle lane next to the platoons and accepted shorter gaps (up to 12.7% shorter at on-ramps) in lane changing manoeuvres. Dedicating a lane to CAVs increases the density of CAV platoons on one lane and consequently their conspicuity becomes higher. As a result, MV drivers are influenced by CAV platoons on a DL and imitate their behaviour.The literature suggests that dedicating a lane to CAVs improves the traffic efficiency by providing more possibilities for platooning. This study shows that implementing such a solution will affect the driving behaviour of human drivers. This should be taken into consideration when evaluating the impacts of dedicated lanes on traffic efficiency and traffic safety.     

Associations between self-reported mindfulness,driving anger and aggressive driving

Anger and aggression on the roads is associated with how drivers evaluate the driving situation and the behaviour of other drivers. Consequently, both can be exacerbated when these evaluations are made superficially and/or when drivers have pre-existing negative schemas regarding certain types of road situations or users. Mindfulness is likely to have negative associations with anger and aggression because it promotes opposing appraisals. That is, it encourages emotion-regulation and involves acceptance of, but not reaction to, the current situation. To examine these associations, a total of 309 drivers responded to an online questionnaire assessing mindfulness, driving anger and aggressive driving. The results showed that mindfulness shared negative relationships with driving anger and self-reported aggressive driving. However, when these relationships were examined simultaneously using Structural Equation Modelling, mindfulness was found to relate only to anger and this, in turn, predicted aggressive driving. Further analysis showed that driving anger mediates the relationship between mindfulness and aggressive driving. These results suggest that mindfulness training may provide a promising intervention for drivers prone to driving anger and subsequent aggression.     

Situational specificity of trait influences on drivers’ evaluations and driving behaviour

This study explored the influence of anger and anxiety traits on driver evaluations and behaviour during a simulated drive. Forty-eight licensed drivers completed identical simulated driving tasks during which they rated levels of current anger, calmness and frustration or levels of danger, calmness and difficulty. Anxiety-prone drivers made higher difficultly evaluations and generally drove more cautiously. Anger-prone drivers gave higher ratings of anger and frustration, but their evaluations and anger tendencies were unrelated to their general driving behaviours. When driving behaviours in high and low anger-provoking situations were contrasted, in low anger-provoking situations, drivers higher in trait anger reported more anger and frustration and also drove faster and with more sideward movement. When driving situations were considered separately, although not overall, behaviour and evaluations were related: when forced to move sideward, drivers reported more frustration; when forced to drive more slowly, they reported more anger, and subsequently increased acceleration, throttle pressure and steering wheel use. These relationships were not moderated by trait anger. Irrespective of trait anger, drivers become angry when impeded, or in other anger-provoking situations, only drivers with high trait anger become angry and behaved aggressively in circumstances most would not consider provocative.     

Drinking,drug use and road rage in Turkish drivers

Alcohol or drug use and road rage behaviors in drivers are threats to traffic safety. The purpose of this research is to examine the relationship between alcohol or drug use and aggression in Turkish drivers, and to evaluate the mediating role of driving anger in this relationship. 270 amateur and professional Turkish drivers (170 male, 100 female) have filled up Driving Anger Scale (DAS), Driver Aggression Indicators Scale (DAIS), Alcohol Use Disorders Identification Test (AUDIT) and the Questionnaire Form. 15.9% of the participants scored 8 and higher on the AUDIT scale (alcohol problem). The most prevalent substance is cannabis, used at least once in a lifetime (20%). The results of mediated regression analysis indicates that driving anger has an increasing mediating role in the relationship between alcohol use and driver aggression. Due to limitations in the data, we could not reveal the relationship between substance use and driver aggression. These findings have led us to think that drinking use may contribute to being a perpetrator and/or a victim of the road rage. Taking precautions against drinking driving and road rage and going over the current implementations is important in order to create a safer traffic environment. Scientific researches carried out in this field must aim to provide the desired efficiency on prevention and intervention programs that reduce the prevalance of such dangerous acts.     

Cognitive biases in aggressive drivers: Does illusion of control drive us off the road?

Anger has been shown to be a motivating factor in aggression and it is widely accepted that driving anger may lead to aggressive driving. However, the link between anger and aggressive driving is likely to be mediated by drivers’ pre-existing cognitive biases and the subsequent situational evaluations made. This study investigated the extent to which optimism bias, illusion of control beliefs and driver anger predict self-reported hostile driving behaviours. A total of 220 licensed drivers (106 men; 114 women) completed a self-report questionnaire measuring trait driving anger, optimism bias, illusion of control and driving behaviour. Structural Equation Modelling showed that trait driving anger and illusion of control beliefs account for 37% of the variance in hostile driving behaviour scores. Optimism biases were unrelated to hostile driving behaviours. Thus, driving anger propensities and feelings of control over the situation, but not a general tendency to underestimate the likelihood of adverse outcomes, predict aggressive driving.     

Development and Evaluation of a Measure of Dangerous,Aggressive, Negative Emotional,and Risky Driving1

The Dula Dangerous Driving Index (DDDI) was created to measure drivers’ self‐reported likelihood to drive dangerously. Each DDDI scale (DDDI Total, Aggressive Driving, Negative Emotional Driving, and Risky Driving scales) had strong internal reliability and there was also evidence for the construct validity of the scales. The DDDI was used to examine the relation between dangerous and aggressive driving and dispositional aggression and anger among 119 college students. Males reported significantly more aggressive, risky, and angry driving than did females. Males and females reported similar levels of dangerous driving and negative emotions while driving. Dangerous driving was positively related to traffic citations and causing accidents. The DDDI will be useful as a research instrument to examine dangerous driving.     

Following slower drivers: Lead driver status moderates driver’s anger and behavioural responses and exonerates culpability

Two experiments investigated the effects of lead-driver status on the anger-experienced and aggression-expressed in traffic scenarios in which the lead drivers’ actions were determined by an event obviously beyond, or within, their control. Experiment I contrasted reactions to lead-cars bearing Learner driver markings (Low Status) or similar unmarked cars (Control), while Experiment II contrasted reactions to Ambulances (High Status) or otherwise identical generic work vans (Control). Reported anger, heart-rate and behaviour were measured while drivers drove. When the lead vehicle slowed or changed course because of the actions of another road user, drivers were reliably more angered when slowed by a learner driver than an unmarked sedan. Drivers reported less anger when slowed by an Ambulance, than by a work van, when there was no apparent cause for the lead-vehicle slowing. Driver behaviour also differed according to lead-vehicle status. Drivers allowed greater headway between themselves and a slower ambulance, but drove closer to the work-van, and followed Learner drivers at a dangerously close distance, leaving greater headway behind a similar, unmarked car. Reliable differences in subjective anger ratings and behaviour suggest that anger experienced and expressed depends not just on the actions of the perpetrator but on the perceived status of that perpetrator. Higher status vehicles appear to be forgiven their indiscretions more readily even when there are no extenuating circumstances, whilst lower status drivers are likely to be blamed more readily for circumstances beyond their control.     

Driving anger in Germany: Validation of the driving anger scale for German drivers

In 1994, Deffenbacher et al. published the Driving Anger Scale (DAS), a tool for assessing a driver’s propensity to experience anger in road traffic. Since then, much research has used this scale to measure the driving anger experienced in various countries around the world. This study examines the scale’s validity for German drivers. It also relates their experiences of anger while driving to their experiences and expressions of anger in general, as well as to certain demographic variables. In addition, it compares German drivers’ experiences of driving anger to those reported by drivers from other countries. We distributed a German version of the DAS and the State-Trait Anger Expression Inventory (STAXI) to a sample of 1136 German drivers. Results showed that a 22-items version of the DAS with six factors produced good fit indices for German drivers. Furthermore, data analysis revealed small to moderate significant relationships between German drivers’ driving anger experiences and their experiences and expressions of anger in general, underlining the idea that driving anger is a personality characteristic that is related to one's general experience and expression of anger. Finally, German drivers' driving anger experiences differed from those of drivers from other countries in that German drivers reported less driving anger than drivers from Spain and New Zealand, comparable levels to those from Turkey, Malaysia, and the United States, and more driving anger than drivers from France, Australia, China, and the United Kingdom. In addition, discourteous driver actions and hostile gestures consistently triggered highest driving anger ratings whereas police presence was rated lowest. Given these results, we conclude that the DAS can be applied to German drivers in its modified version.     

Situational influencing factors on understanding cooperative actions in automated driving

Cooperative interacting vehicles are a promising approach in the context of automated driving. To ensure understanding and acceptance of such systems, the underlying mechanisms of human cooperation in the context of traffic must be understood. In a driving simulator study, we investigated how situational factors influence cooperative behaviour in a lane change situation on a two-lane German highway during automated driving in the left lane. When another car in the right lane was approaching a slower truck, participants (N = 32) were asked by an automated system to either accelerate, decelerate or maintain speed. The driver’s scope of action, the situation’s criticality for the lane-changing vehicle and the display of intention to change lanes were manipulated. A hierarchical multinomial logistic regression revealed that a wider scope of action, a higher situation’s criticality and signalling the intention to change lanes positively influenced cooperative behaviour by accelerating and decelerating. These results might be applied to design user-centred automated cooperatively interacting vehicles.     

Anger,aggression, and risky behavior: a comparison of high and low anger drivers

This research tested hypotheses from state-trait anger theory applied to anger while driving. High and low anger drivers drove equally often and as many miles, but high anger drivers reported more frequent and intense anger and more aggression and risky behavior in daily driving, greater anger in frequently occurring situations, more frequent close calls and moving violations, and greater use of hostile/aggressive and less adaptive/constructive ways of expressing anger. In low impedance simulations, groups did not differ on state anger or aggression; however, high anger drivers reported greater state anger and verbal and physical aggression in high impedance simulations. High anger drivers drove at higher speeds in low impedance simulations and had shorter times and distances to collision and were twice as likely to crash in high impedance simulations. Additionally, high anger drivers were more generally angry. Hypotheses were generally supported, and few gender differences were noted for anger and aggression.     

Driving aggression in forensic and non‐forensic populations: Relationships to self‐reported levels of aggression,anger and impulsivity

A series of four questionnaires — the Buss‐Perry Aggression Questionnaire (AQ), the Barratt Impulsivity Scale (BIS‐11), the Driving Anger Scale (DAS) and a Driving Violence Inventory (DVI) — were administered to a sample of 473 British drivers consisting of undergraduates (N=185), members of the public (N=106) and offenders (N=182) serving sentences in closed prisons in England (violent=82, non‐violent=100). Offenders consistently rated acts of driving aggression as less severe compared with other drivers. Offender attributions of driving violence differed to other drivers in that they were equally likely to perceive obscene gesturing as high or low intensity responses; they also viewed assault as a high intensity response whereas members of the public rated it more severely. Trait levels of anger and aggression were the predictors of driving violence in all groups but previous aggressive behaviour was only a predictor for the offenders. Gender and age were found to be predictors of aggressive driving in non‐offenders. Even with the effects of age controlled, offenders (and violent offenders in particular) scored higher on measures of driving anger and aggression. These data suggest that offenders differ in their perceptions of aggressive behaviours experienced in everyday driving and as a consequence are more likely to commit acts that other drivers perceive as violent. As offenders are known to display similar perceptual biases in other domains, identified as precursors to their aggressive behaviour, it seems likely that experience effects (as reflected in the trait measures) underpin differences in driving aggression between offenders and non‐offenders.     

Situational (state) anger and driving

Aggression and anger have been related to crash involvement, but the direct causal relation between situational anger and driving choices and abilities has not been examined empirically. In this study, 15 licensed drivers drove twice in a driving simulator, each time following one of two emotion inductions based on event recall: angry and neutral. Following anger induction, the drivers crossed more yellow traffic lights (p < .01) and tended to drive faster (non-significant). However, performance on emergency manoeuvres were unaffected by anger. In conclusion, it appears that state anger affects driving behaviour by increasing risk taking, without necessarily compromising the skilled driving behaviour, at least as far as these behaviours were evaluated in emergency situations in simulated driving.     

User-related assessment of a Driver Assistance System for Continuous Support – A field trial

A Driver Assistance System for Continuous Support continuously evaluates the status of the host vehicle as well as the surrounding traffic based on information from on-board sensors. When the system detects a hazard, it issues a warning to the driver, depending on the degree of the hazard. The effects of this system on driver behaviour and acceptance were evaluated in a field trial carried out in 2013. Twenty-four drivers took part in test drives with a within-subject design along a 53 km test route containing motorway and rural-road sections. Driving data was logged and the test drivers were observed by means of an in-car observation method (Wiener Fahrprobe); in this case by two observers in the car along with the driver. Questionnaires were used to assess the drivers’ comprehension of and reaction to the system. The system was successful in affecting driver behaviour in terms of lower speed when negotiating curves. Positive effects were found in the form of better speed adaptation to the situation during driving with the system activated. Also, lane choice and lane change improved with the system on. When it came to speed limit compliance, driving speed in general and longitudinal and lateral positioning, no effects could be found. No major differences were found regarding distance to the vehicle in front, overtaking manoeuvres, stopping behaviour at intersections, driving against yellow at traffic lights and interaction behaviour with other road users while driving with or without the system. On the negative side, it was noted that only during driving with the system activated did the test drivers make turns at intersections at too high speeds. In addition, more errors associated with dangerous distance to the side were observed with the system activated. In terms of the emotional state of the driver, the only difference found was that the drivers felt an increase in irritation. Regarding subjective workload, the drivers only assessed one item, i.e. whether their performance decreased statistically significantly while driving with the system. The test drivers were of the opinion that the system was useful, and that it would enhance safety especially in overtaking manoeuvres on motorways. The blind-spot warning was found especially useful in the overtaking process. The drivers appreciated the fact that the system did not give information all the time.     

“What Makes a Cooperative Driver?” Identifying parameters of implicit and explicit forms of communication in a lane change scenario

An automated vehicle needs to learn how human road users communicate with each other in order to avoid misunderstandings and prevent giving a negative outward image during interactions. The aim of the present work is to develop an autonomous driving system which communicates its intentions to change lanes based on implicit and explicit rules used by human drivers. To reach this goal, we aimed at gaining a deeper understanding of which aspects of lane change behaviour makes them cooperative from the perspective of other drivers. Therefore a vehicle used various lane change announcement strategies by varying combinations of driving parameters in a static driving simulator. (First study: Start indicator signal, Waittime, lane change duration; Second study: Longitudinal acceleration). It’s impact on the perception and behaviour of other road users was observed in two studies (N = 25 per study). The results showed that the earlier the merging vehicle was indicating its intentions, the more cooperative it was perceived. When turning on the indicator at a later time participants considered it as more cooperative to merge with a slower or faster lane change duration or to wait longer in the lane before starting to move to the other lane. An early longitudinal acceleration when starting to change lanes is perceived more cooperative. These findings can be used to model a lane change strategy based on human behaviour, which will eventually lead to more acceptable and safer interactions between automated and non-automated road users.