Driver performance, rewards and motivation: A simulator study

It has been suggested that effort invested in a task may be moderated by the perception of the nature of reward offered, e.g., whether social or financial in nature. If levels of payment for empirical work meaningfully influence the effort invested in tasks by participants, the implications may be serious and wide-ranging for the reliability and validity of published data. The study reported in this paper, examines this thesis in a driving context. Thirty-six participants were allocated to either a No payment, Low payment or Medium payment condition in a driving simulator. They undertook both easy and difficult driving scenarios in which performance was measured. Subjective workload and performance results indicated that task difficulty was successfully manipulated with the study. However, in contrast to the previous research in non-driving contexts, participants not receiving rewards were found to perform more poorly and experience increased time pressure.     

Individual differences and propensity to engage with in-vehicle distractions - A self-report survey

Ratings of severity and frequency of engagement with distracting driver behaviours are reported in this paper. Survey data were collected using an anonymous online questionnaire. Four hundred eighty-two respondents contributed to the survey during a 2 month data collection period. Results indicate that the three behaviours rated as most distracting when driving were (i) writing text messages (41%), (ii) reading text messages (62%), and (iii) using a cellular telephone hand-held (52%). The three most frequently reported distracting behaviours that resulted in accidents were (i) ‘interaction with child passengers’ 2.1% (near misses = 7.5%), (ii) both, route guidance destination entry with 2% (near misses = 2.8%) and use of an ‘… add-on media device, e.g., an iPod’ with 2% (near misses = 3.9%), and (iii) the three items ‘reading a text message’, ‘following advice from a route guidance system’, and ‘interaction with pets’, all with 1.7% of respondents reporting an accident when undertaking the activity (with 6.5%, 3%, and 2.2% respectively for near misses). Two hierarchical regression models were explored. The first introducing personal factors, i.e., age, extraversion, agreeableness, conscientiousness, emotional stability and intellect (R² = 0.131, p < 0.001). The second controlled for variables in the first model and introduced driver-related variables, mileage, penalty points, and frequency of accidents with assumed responsibility (R² = 0.253, p < 0.001). This model identified age, extraversion, mileage, penalty points and accidents all to be significant predictors of engagement with unnecessary distractions. The data presents a picture of widespread awareness of, and engagement with, distracting behaviours by drivers in the United Kingdom. Findings from the hierarchical regressions suggest scope may exist to mediate the levels of distracting behaviours by exploring individual differences and driving styles.     

But I can’t pass that far! The influence of motor skill on decision making

Objectives

The influence of motor skill on perceptual-cognitive and perceptual-motor decision making has been theorised but not verified empirically.

Method

Expert (n = 19), developmental (n = 20), and lesser-skilled netballers (n = 19) completed tests designed to evaluate three different components of domain-specific expertise: (i) motor skill-execution; (ii) perceptual-cognitive decision making; and (iii) perceptual-motor decision making.

Results

Each of the three measures was found to improve commensurate with domain-specific skill. Decisions requiring movements (perceptual-motor) elicited more accurate decision making than simple verbal responses (perceptual-cognitive), irrespective of participant skill. Although motor skill was found to be related to the successful execution of a most appropriate movement in a game situation, it was not found to limit the nature of the decision made by participants. No evidence was found to support the supposition that lesser-skilled participants bias their perceptual-cognitive decisions towards ones supported by their motor ability.

Conclusions

Results fail to comprehensively support the contemporary models for the development of perceptual-cognitive and perceptual-motor skill in sport.     

On-road trust and perceived risk in Level 2 automation

To encourage appropriate use of driving automation, we need to understand and monitor driver’s trust and risk perception. We examined (1) how trust and perceived risk are affected by automation, driving conditions and experience and (2) how well perceived risk can be inferred from behaviour and physiology at three levels: over traffic conditions, aggregated risk events, and individual risk events.30 users with and without automation experience drove a Toyota Corolla with driving support. Safety attitude, subjective ratings, behaviour and physiology were examined.Driving support encouraged a positive safety attitude and active driver involvement. It reduced latent hazards while maintaining saliently perceived risks. Drivers frequently overruled lane centring (3.1 times/minute) and kept their feet on or above the pedals using ACC (65.8% of time). They comfortably used support on curvy motorways and monotonic and congested highways but less in unstable traffic and on roundabouts. They trusted the automation 65.4%, perceived 36.0% risk, acknowledged the need to monitor and would not engage in more secondary tasks than during manual driving.Trust-in situation reduced 2.0% when using automation. It was 8.2% higher than trust-in-automation, presumably due to driver self-confidence. Driving conditions or conflicts between driver and automation did not affect trust-in-automation.At the traffic condition level, physiology showed weak and partially counter-intuitive effects. For aggregated risk events, skin conductance had the clearest response but was discernible from baseline in  < 50%. Pupil dilation and heart rate only increased with strong braking and active lane departure assist. For individual risk events, a CNN classifier could not identify risk events from physiology. We conclude that GSR, heart rate and pupil dilation respond to perceived risk, but lack specificity to monitor it on individual events.     

Behavioural adaptation or constraint? The effect of curve proximity on driving behaviour

Horizontal curves are typically associated with increased crash risk when compared with straight roads, but recent analyses have suggested that having more frequent sharp curves decreases the relative crash risk posed by each curve. Here, 90 drivers completed a simulated rural drive with either high proximity (160 m straight tangent between curves) or low proximity (1200 m tangent) curves. Curve proximity had a significant effect on approach speeds, with drivers in the high proximity curve drive showing significantly lower mean and maximum approach speeds before entering the curve. However, they also showed an unexpected tendency to higher speeds while negotiating the curve itself. The current study provides direct empirical evidence that driving behaviour on approach to a given curve is significantly affected by the proximity of other curves, and therefore highlights the need to factor in the characteristics of the road on approach to the curve, as well as the features of the curve itself when assessing risk.     

Handing control back to drivers: Exploring the effects of handover procedure during transitions from Highly Automated Driving

The operational capabilities of automated driving features are limited and sometimes require drivers’ intervention through a transition of control. Assistance at an operational level might be extremely beneficial during transitions but the literature lacks evidence on the topic. A simulator study was conducted to investigate the potential impacts that lateral assistance systems might have while the Automated Driving System (ADS) hands back control to the driver. Results showed that drivers benefitted from a strong Lane Keeping Assist during the first phase of the transfer, helping them to keep the lane centre. However, assisting the drivers at an operational level did not enhance their capability of addressing a more complex task, presented as a lane change. In fact, it was more task-specific assistance (Blind-spot assist) that allowed drivers to better cope with the tactical decision that the lane change required. Moreover, longer exposure to lane-keeping assist systems helped them in gaining awareness of the surrounding traffic and improved the way drivers interacted with the Blind-spot assist.     

Driver social desirability scale: A Turkish adaptation and examination in the driving context

Self-report data collection methods are widely used techniques to gather information in studies related to road safety. One of the most considerable limitations of self-reports is social desirability bias. One way to overcome the possible detrimental effects of socially desirable responding is to control it by using social desirability scales. With respect to that, the present study aims to adapt the Driver Social Desirability Scale into Turkish, examine its construct validity, and investigate the relationship between social desirability and driving-related measures. A total of 351 drivers between the ages of 19 and 59 completed a questionnaire including a demographic information form, the Driver Behavior Questionnaire (DBQ), the Driver Skill Inventory (DSI), the Two-Dimensional Social Desirability Scale (SDS), and the Driver Social Desirability Scale (DSDS). Factor analysis supported the two-factor structure of the DSDS in the Turkish sample. Social desirability correlated positively with age and driving experience. Female drivers reported higher levels of driver impression management, while male drivers scored higher on self-deception. Driver impression management was associated negatively with violations and perceptual-motor skills and positively with safety skills. Lastly, driver self-deception was positively related to violations, positive driver behaviors, perceptual-motor skills, and safety skills. The study shows that the Turkish version of the DSDS is a reliable and structurally valid instrument with incremental validity compared to the general social desirability measure in predicting driving-related outcomes.     

What happens when drivers of automated vehicles take over control in critical lane change situations?

According to legislation, take-overs initiated by the driver must always be possible during automated driving. For example, when drivers mistrust the automation to handle a critical and hazardous lane change, they might intervene and take over control while the automation is performing the maneuver. In these situations, drivers may have little time to avoid an accident and can be exposed to high lateral forces. Due to lacking research, it is yet unknown if they recognize the criticality of the situation and how they behave and perform to manage it. In a driving simulator study, participants (N = 60) accomplished eight double lane changes to evade obstacles in their lane. Time-to-collision and traction usage were varied to establish different degrees of objective criticality. To manipulate these parameters as required, participants were triggered to take over control by an acoustic cue. This setting shows what might happen if drivers disable the automation and complete the maneuver themselves. The results of the experiment demonstrate that drivers rated objectively more critical driving situations as more critical and responded to the hazard very fast over all experimental conditions. However, their behavior was more extreme with respect to decelerating and steering than necessary. This impaired driving performance and increased the risk of lane departures and collisions. The results of the experiment can be used to develop an assistance system that supports driver-initiated take-overs.     

Assessing the potential impacts of connected vehicle systems on Driver’s situation awareness and driving performance

Vehicles equipped with connected vehicle technologies are able to communicate with each other and with infrastructures. Compared to Advanced Driving Assistance Systems (ADAS) using camera systems and sensor technologies, the Connected Vehicle Systems (CVS) leverage the wireless communication networks to detect hazards with a greater range, alert drivers of hazards much earlier, and therefore enhance driving safety. However, drivers’ reliance on the CVS to detect critical situations could negatively affect them maintaining situation awareness (SA) in noncritical situations when no warning is issued by the CVS. The present study conducted a driving simulator experiment with 40 participants to investigate the effect of connected vehicle systems on driver SA in normal, noncritical driving scenarios after they were exposed to the CVS with different designs of collision warning lead time (3 s, 6 s, and no warnings). After drivers experienced the CVS-supported warnings with the assigned design of lead time in critical situations, driver SA was measured in normal driving conditions using the freeze probe technique. Results revealed that drivers who experienced the CVS with early warnings (6 s) showed lower SA for normal driving events compared to those who experienced the CVS with late warnings (3 s) or no warnings. Although early warnings of CVS brought more safety benefits to drivers in critical situations, the degraded driver SA due to drivers’ reliance on such warning systems could endanger drivers when a system failure occurred. These findings highlight the importance of balancing the effects of warning lead time on driver SA and driving performance in designing connected vehicle systems.     

Personality and demographic differences in the perceived risks of potentially timid driving behaviours

Timid driving behaviours can be described as overly cautious and hesitant driving behaviours. Little research has examined behaviours that potentially resemble timid driving and how these behaviours are perceived by other drivers. This is despite the potential for these behaviours to be perceived in a way that leads to angry and aggressive retaliatory behaviours in some drivers (e.g., in anger-prone drivers). We conducted an online survey examining the perceived road safety risks of several behaviours that could potentially result from timid driving and their relationships with driver personality (trait anxiety, trait driving anger), behaviour (anxious driving, angry driving), and demographic (age, gender, annual mileage) background. Drivers (N = 439, M_age = 49.41 ± 5.59 years, aged 18–89) perceived excessively cautious and unpredictable braking behaviours as posing moderate levels of risk. Multiple linear regression analyses also indicated higher perceived risks of slow and excessively cautious behaviours in older, male, and anger prone drivers. No meaningful associations were found between driver characteristics and the risks of unpredictable braking behaviours. These results suggest that safety campaigns to reduce aggressive behaviour may benefit from targeting the perceptions of other drivers’ behaviours.