Driver stress as influenced by driving maneuvers and roadway conditions

Excess stress can influence driving performance and increase crash likelihood. The level of stress can also vary based on different driving conditions. Past research has not differentiated among these conditions, but rather has focused on individual driver differences. The goal of this study is to understand how different driving tasks and roadway conditions may influence the stress perceived by drivers. This was accomplished using data from a survey that assessed drivers’ stress under various road, traffic and weather-related scenarios. Factor analytic techniques were used to find groups of driving scenarios that generate similar stress levels in drivers. The results revealed four scenarios that were categorized in terms of (1) weather, (2) visibility, (3) interactions with other drivers, and (4) driving tasks. Ordered logistic regression models were then used to determine the effect of socioeconomic characteristics, trip behavior, and crash history for different stressful driving scenarios. Increases in stress with these four factors were influenced by age and gender, with females being more likely to report higher levels of stress than males. The effect of age varied in that older drivers generally reported higher stress levels, except when interacting with other drivers. Drivers with a history of crashes reported significantly higher stress levels when there was limited visibility, in adverse weather, and while performing common driving tasks. The results revealed that stress depends not only on driver characteristics, but also on the specific driving environment.     

Older drivers’ self-assessed driving skills,driving-related stress and self-regulation in traffic

Previous research on older drivers has indicated connections between self-rated driving ability, confidence in their own driving, driving-related stress, and self-regulatory behaviour. However, more systematic associations between older drivers’ perceptions on their own driving and self-regulation or driver stress and self-regulation behaviour, and possible gender differences in these, have not been obtained in previous studies. The aim of the present study was to gain a better understanding of older drivers’ self-regulatory driving and the motivators behind this behaviour, by placing this behaviour in the modern traffic psychological framework of the driving task. 888 drivers aged 75 or older completed a structured phone interview about their perceived changes in driving skills, driving-related discomfort, and avoidance of driving situations. The results showed that when reporting change, the participants were more likely to report improvement of higher level skills and decline of the lowest level skills. Women were less likely to report improvement and more likely to report decline of skills. Driving situations related to inner states or adverse conditions were more often associated with discomfort and avoidance than situations related to infrastructure, and women were more likely to report discomfort and avoidance of driving situations. The results suggest that older drivers generally show good self-judgement of changes in their driving skills and acknowledge the different types of skills comprised in the driving task. The results also provide a better understanding of older drivers’ self-regulation of driving and gender differences in this, thus providing a better understanding in particular of women drivers’ self-regulation and increased risk of premature driving cessation. These findings may be valuable when encouraging older drivers, especially women, to prolong their driving.     

Professional and non-professional drivers’ stress reactions and risky driving

The aim of the present study was to investigate stress reactions, speeding, number of penalties and accident involvement among different driver groups (taxi drivers, minibus drivers, heavy vehicle drivers, and non-professional drivers). A total number of 234 male drivers participated in the study. The participants were asked to complete the Driver Stress Inventory (DSI) together with a demographic information form. Five dimensions of the DSI were measured; aggression, dislike of driving, hazard monitoring, fatigue proneness, and thrill-seeking. After controlling the effects of age and annual mileage, the results of the ANCOVAs revealed differences between different driver groups in terms of both risky driving behaviours and stress reactions in traffic. Regression analyses indicated that aggression, dislike of driving, and hazard monitoring dimensions of the DSI were related to accident involvement after controlling for the effects of age, annual mileage and driver group. Dislike of driving and thrill-seeking dimensions of the DSI were related to speeding on in-city roads.     

The impact of courteous and discourteous drivers on physiological stress

Prior studies into road safety have concentrated largely on studying unsafe forms of driving behaviour such as aggressive, stressed, and risky driving. Little attention has been given to ‘positive’ driving behaviour, such as how pro-social driving may help to promote cooperation with other road users and decrease incidences of aggressive and stressful driving. This study aimed to compare the impact of courteous and discourteous driving on the immediate physical health of other drivers (blood pressure, heart rate, and markers of stress) whilst controlling for other recognized factors responsible for driver stress such as road infrastructure (e.g. roadworks, traffic lights, freeways) and driving maneuvers (e.g. merging, tail-gaiting, navigating roundabouts). Using actors in a deception study, a naturalistic driving scenario was created in a lab-based simulation. All participants (n = 10; 39 ± 14.5 years) drove the same route in a simulator and engaged with the same driving behaviours and other virtual road users on two separate occasions separated by 7 days. The difference between conditions was whether the participant interacted with other drivers who displayed: a) courteous or b) discourteous behaviours. Blood pressure, heart rate variability and salivary hormone concentrations (cortisol and alpha amylase) were measured before and immediately after each simulated drive. After interacting with the discourteous drivers, participants experienced significantly higher mean arterial blood pressure, systolic and diastolic pressure, central systolic and diastolic pressure, and heart rate, and lower heart rate variability (indicative of acute stress) compared to interacting with the courteous drivers. Conversely, these markers of stress were reduced after interacting with the courteous drivers. The results support courtesy on the road to provide short-term benefits for the recipient of the action, while also increasing road safety more generally.     

Secondary task engagement and disengagement in the context of highly automated driving

During highly automated driving (level 3 automation according to SAE International, 2014) people are likely to increase the frequency of secondary task interactions. However, the driver must still be able to take over control within a reasonable amount of time. Previous studies mainly investigated take-over behavior by forcing participants to engage in secondary tasks prior to take over, and barely addressed how drivers voluntarily schedule secondary task processing according to the availability and predictability of automated driving modes. In the current simulator study 20 participants completed a test drive with alternating sections of manual and highly automated driving. One group had a preview on the availability of the automated driving system in upcoming sections of the track (predictive HMI), while the other drivers served as a control group. A texting task was offered during both driving modes and also prior to take-over situations. Participants were free to accept or reject a given task, taking the situational demands into account. Drivers accepted more tasks during highly automated driving. Furthermore, tasks were rejected more often prior to take-over situations in the predictive HMI group. This was accompanied by safer take-over performance. However, once engaged in a task, drivers tended to continue texting even in take-over situations. The results indicate the need to discriminate different aspects of task handling regarding self-regulation: task engagement and disengagement.     

How to identify the take-over criticality in conditionally automated driving? An examination using drivers’ physiological parameters and situational factors

Autonomous vehicles and advanced driver assistance technology are growing exponentially, and vehicles equipped with conditional automation, which has features like Traffic Jam Pilot and Highway Assist, are already available in the market. And this could expose the driver to a stressful driving condition during the takeover mission. To identify stressful takeover situations and better interact with automated systems, the relationship and effect between drivers’ physiological responses, situational factors (e.g., takeover request [TOR] lead time, takeover frequencies, and scenario types), and takeover criticality were investigated.34 participants were involved in a series of takeover events in a simulated driving environment, which are varied by different TOR lead time conditions and driving scenes. The situational factors, drivers’ skin conductance (SC), heart rate (HR), gaze behaviors, and takeover criticality ratings were collected and analyzed. The results indicated that drivers had a higher takeover criticality rating when they experienced a shorter TOR lead time level or at first to fourth take-overs. Besides, drivers who encountered a dynamic obstacle reported higher takeover criticality ratings when they were at the same Time to collision (TTC). We also observed that the takeover situations of higher criticality have larger driver’s maximum HR, mean pupil size, and maximum change in the SC (relative to the initial value of a takeover stage). Those findings of situational factors and physiological responses can provide additional support for the designing of adaptive alert systems and environmental soothing technology in conditionally automated driving, which will improve the takeover performances and drivers’ experience.     

Age group differences in self-reported aggressive driving perpetration and victimization

Aim

This study examined whether the predictors of self-reported aggressive driving perpetration and victimization vary across age groups.

Method

Based on data from a general-population telephone survey conducted from July 2002 through June 2005, three groups of drivers were examined: 18–34 year-olds (N = 1522), 35–54 year-olds (N = 2726), and 55 years of age or older (N = 1883). For each age group sample, logistic regression analyses examined self-reported aggressive driving perpetration and victimization in the last 12 months by measures of driving exposure, heavy drinking, cannabis use, and drinking-driving, while controlling for demographic factors.

Results

The prevalence of aggressive driving perpetration within the past year was highest for the youngest age group (51%), followed by the middle-aged group (37%), and then the oldest age group (18%). The same pattern of results was found for prevalence of aggressive driving victimization (54%, 47%, and 31%, respectively). Controlling for demographic factors, the predictors of perpetration were generally consistent across the age groups. The logistic regression model for the youngest drivers revealed that those who reported stressful driving, heavy drinking, and cannabis use had significantly increased odds of reporting perpetration of aggressive driving. For middle-aged and older drivers, stressful driving, driving on busy roads, cannabis use, and driving after drinking were associated with perpetration. In addition, increased mileage contributed to perpetration in the oldest group. The findings for victimization by aggressive driving were similar. The logistic regression model for the youngest age group identified stressful driving, cannabis use, and higher annual mileage as being associated with victimization. For the oldest age group, these same variables were significant predictors of victimization, in addition to driving on busy roads. The logistic regression for the middle-aged group identified the same predictors as that of the oldest age group; however, interestingly driving after drinking was found to predict lower victimization among middle-aged drivers.

Conclusions

Although the prevalence of aggressive driving perpetration and victimization declined with age, the factors that contributed to aggressive driving remained generally stable across the lifespan. The results suggest that efforts to reduce aggressive driving among young drivers may prove to be effective for drivers from all age groups.     

The appraisal of roadway environment and infrastructure by drivers with autism: A qualitative study

People with an autism spectrum disorder (ASD) might experience difficulties while driving, for instance, related to hazard perception. These difficulties may be related to cognitive issues (internal) such as attention-shifting, sequential performance, and multitasking. Possibly related to these issues, some people with ASD experience stress and anxiety while driving. Among other reasons, stress could relate to the roadway environment and infrastructure design, e.g., sensory overload due to lighting conditions. Yet, the relationship between roadway environment and infrastructure and driving experiences of people with ASD is somewhat overlooked in previous research. This study aimed to (1) explore how people with ASD experience roadway environment/infrastructure while driving (2) identify coping strategies to deal with interfering elements related to roadway environment/infrastructure. There were twelve participants (mean age: 34.8, of which 66.7% were female), semi-structured interviews to examine the appraisal of roadway environment and infrastructure. The interviews were analyzed based on a phenomenological hermeneutical approach. Each participant reported both positive (e.g., environment and infrastructure can be supporting, enhance predictability) and negative appraisals (e.g., stress, anxiety) to roadway environment/infrastructure. Various elements such as light, noise, and, being rushed caused additional pressure on (1) the driving performance (e.g., driving too slowly, not noticing important elements), (2) traffic analyzing skills (e.g., difficulties in overseeing new situations), (3) and the efficient application of traffic rules. The participants described different coping mechanisms to deal with the influence of interfering elements; for example, alternative transport means or adjusting behavior (e.g., switch off radio, early departure). This demonstrates that besides internal factors such as attention, external factors like roadway environment and infrastructure can also influence the driving experience of ASD drivers, potentially leading to driving-related stress and anxiety. Policymakers could consider the current findings when designing new guidelines and roadway environment and infrastructure design principles.     

Controllability of Partially Automated Driving functions – Does it matter whether drivers are allowed to take their hands off the steering wheel?

Different motor vehicle manufacturers have recently introduced assistance systems that are capable of both longitudinal and lateral vehicle control, while the driver still has to be able to take over the vehicle control at all times (so-called Partial Automation). While these systems usually allow hands-free driving only for short time periods (e.g., 10 s), there has been little research whether allowing longer time periods of hands-off driving actually has a negative impact on driving safety in situations that the automation cannot handle alone. Altogether, two partially automated assistance systems, differing in the permitted hands-off intervals (Hands-off system vs. Hands-on system, n = 20 participants per assistance condition, age 25–70 years) were implemented in the driving simulation with a realistic take-over concept. The Hands-off system is defined by having a permitted hands-off interval of 120 s, while the Hands-on system is defined by a permitted hands-off interval of 10 s. Drivers’ reactions at a functional system limit were tested under conditions of high ecological validity: while driving in a traffic jam, participants unexpectedly encountered a time-critical situation, consisting of a vehicle at standstill that appeared suddenly and required immediate action. A visual-auditory take-over request was issued to the drivers. Regardless of the hands-off interval, all participants brought the vehicle to a safe stop. In spite of a stronger brake reaction with the Hands-on system, no significant differences between assistance levels were found in brake reaction times and the criticality of the situation. The reason for this may be that most of the drivers kept contact with the steering wheel, even in the Hands-off condition. Neither age nor prior experience with ACC was found to impact the results. The study thus demonstrates that permitting longer periods of hands-off driving does not necessarily lead to performance deficits of the driver in the case of take-over situations, if a comprehensive take-over concept is implemented.     

Aging and driving in a complex world: Exploring age differences in attentional demand while driving

We investigated the relationship between attention and road complexity in a convenience sample of older drivers. The study sought to examine the impact of age-associated changes in attention in response to situations with an elevated risk of crash. Scenarios were manipulated in terms of handling and information processing complexity. Twenty-six older drivers and 30 mid-aged drivers completed a series of 20 simulated driving scenarios incorporating either rear-end or crossing path situations. For each scenario, the complexity of the driving environment was systematically manipulated in terms of vehicle handling and information processing elements. The attentional demands of half of the scenarios were assessed by means of a peripheral detection task (PDT) as well as through a subjective measure of overall difficulty. The results indicated that when information processing demands were increased, through the addition of traffic, and buildings, all participants exhibited greater workload regardless of age. While no main effects of age were observed, older drivers did exhibit significantly longer PDT responses in the low vehicle handling condition of the crossing path scenario. The results confirm the impact of environmental complexity on attention but suggest that the PDT may not be the most appropriate means of assessing attentional demands among older drivers, particularly when the driving complexity is elevated.     

Evidence that implementation intentions reduce drivers’ use of mobile phones while driving

Implementation intentions are IF-THEN plans that have the potential to reduce mobile phone use while driving and thus contribute towards the prevention of road traffic crashes. We tested whether an intervention, designed to promote the formation of implementation intentions, could reduce drivers’ use of mobile phones. A randomized controlled design was used. The participants (N = 136) were randomised to an implementation intention or a control condition. Self-report questionnaires were administered to all participants at both pre- and one-month post-intervention to measure the use of mobile phones while driving, goal intentions and the theoretically derived motivational pre-cursors of goal intentions (attitudes, subjective norm and perceived behavioural control). Immediately following the pre-intervention questionnaire, the participants in the implementation intention condition (n = 67) were given a volitional help sheet, which asked them to form implementation intentions by specifying target driving situations that tempted them the most to use a mobile phone and linking them with goal-directed responses that could be used to resist the temptation. The participants in the control condition (n = 69) were asked to specify target situations that tempted them the most to use a mobile phone while driving and to generally try to avoid using a mobile phone in those situations. One-month post-intervention, the participants in the implementation intention condition reported using a mobile phone less often while driving in their specified target driving situations than did the participants in the control condition. As expected, no differences were found between the conditions in the reported frequency of mobile phone use in unspecified driving situations, goal intentions or any motivational pre-cursor of goal intentions. The implementation intention intervention that was tested in this study is a potentially effective tool for reducing mobile phone use while driving in target driving situations, where behaviour-change is most needed.     

Driving-induced stress in urban college students

Urban college student commuters (N = 407) were surveyed about their experiences with stress induced by driving. Of the participants 23.6% reported becoming angry at another driver more than once per day. They rated stress from other drivers as equal to the stress experienced during a college examination but gave slightly lower ratings to traffic congestion, road construction, and finding a parking place as sources of stress. Slow drivers, a child not restrained, and a vehicle following too closely were the highest rated annoying situations. Of participants, 21.6% had reported another driver to the police; nearly 22% said they carried a weapon for protection from other drivers (5.4% said a gun). Men were more than twice as likely as women to carry a weapon and three times as likely to carry a gun. Of the total sample, 19.1% feared being shot by another driver. Most participants (75.8%) said drivers were more aggressive and dangerous than they were five years ago.     

Understanding the influence of in-vehicle information systems on range stress – Insights from an electric vehicle field experiment

Battery electric vehicle (BEV) drivers frequently report concerns of becoming stranded as a result of battery depletion, widely referred to as range stress, which constitutes a main obstacle to the adoption of these vehicles. One promising solution identified to mitigate range stress is to provide appropriate and accurate information through in-vehicle information systems (IVISs). Therefore, we aim to gain a broader understanding on the influence of specific IVISs on drivers’ range stress perception. To accomplish this, we performed a BEV field experiment in real traffic situations. By placing participants in a critical range situation, we could measure their psychometric range appraisal and psychophysiological feedback. The results of the psychometric evaluation revealed that individuals perceived the critical range situation as less challenging and threatening with the provided IVISs. Physiological indicators were found to be useful in complementing questionnaire-based evaluation methods within the field of range stress. Although the findings of the psychophysiological measurement revealed that IVISs-equipped participants exhibited increases in stress perception over time due to volatile range feedback, the average stress level was observed to be lower throughout the entire driving task.     

Strategic changes in task performance in simulated car driving as an adaptive response to task demands

Car drivers appear to reduce their driving speed in high task demand situations. Summala's [Safety Sci. 22 (1996) 103–117]; [in: J.A. Rothengatter, & E. Carbonell Vaya (Eds.), Traffic and Transport Psychology: Theory and Application, Pergamon, Oxford, 1997, pp. 41–52] model of behavioural adaptation (MBA) also assumes that drivers increase speed in low task demand situations or attend to additional tasks more. The present study investigated the relation between driving speed and task demands in simulated driving. Participants were observed under three speed conditions, driving fast, driving as if taking a driving test, and following a fast-driving car. The same route was driven twice under each of these speed conditions: once with and once without the concurrent performance of an auditory short-term memory task. All other things being equal, driving fast required more effort than driving more slowly, which was not compensated for by better memory performance. This refutes one assumption of the MBA. When following a fast-driving car, participants invested less effort than when driving fast. As auditory route guidance messages were embedded within the memory task, participants were forced to attend the memory task in all rides of the Fast and Accurate conditions, but not in the Car Following conditions. This can also explain why the memory task had no effect on cognitive effort. It is concluded that car drivers prioritise their task goals.     

Effects of explanation-based knowledge regarding system functions and driver’s roles on driver takeover during conditionally automated driving: A test track study

The present study was designed to examine the influence of explanation-based knowledge regarding system functions and the driver’s role in conditionally automated driving (Level 3, as defined in SAE J3016). In particular, we studied how safely and successfully drivers assume control of the vehicle when encountering situations that exceed the automation parameters. This examination was conducted through a test-track experiment. Thirty-two younger drivers (mean age = 37.3 years) and 24 older drivers (mean age = 71.1 years) participated in Experiments 1 and 2, respectively. Adopting a between-participants design, in each experiment the participants were divided into two age- and sex-matched groups that were given differing levels of explanation-based knowledge concerning the system limitations of automated driving. The only information given to the less-informed groups was that, during automated driving, drivers may be required to occasionally assume control of the vehicle. The well-informed groups were given the same information, as well as details regarding the auditory-visual alerts produced by the human–machine interface (HMI) during requests to intervene (RtIs), and examples of situations where RtIs would be issued. Ten and nine RtI events were staged for each participant in Experiment 1 and 2, respectively; the participants performed a non-driving-related task while the automated driving system was functioning. For both experiments it was found that, for all RtI events, more participants in the well-informed groups than the less-informed groups successfully assumed control of the vehicle. These results suggest that, in addition to providing information regarding the possible occurrence of RtIs, explanations of HMI and RtI-related situations are effective for helping both younger and older drivers safely and successfully negotiate such events.     

Young drivers’ perception of hazards: Variation with experience and day versus night

Young novice drivers have a relatively high crash risk for several years following initial licensing, and while all drivers are at greater risk at night, the night-time increase is greater for inexperienced drivers. Poor hazard perception has been identified as an important contributor to inexperienced drivers’ risk, but research on day-night differences in hazard perception for drivers varying in experience is lacking. This exploratory study investigated the nature of hazards reported by young inexperienced drivers versus more experienced and slightly older drivers. Hazards were not pre-identified by researchers; participants were simply provided with a general definition of ‘hazard’. Analysis focused on how experience level affected qualitative differences in the kinds of hazards reported, with particular focus on day-night differences.The 53 participants ranged in driving experience from learners through to 5+years post licensing, and in age from 16 to 30 years. They viewed 14 day- and night-time video clips of a diverse range of driving situations, pausing the video whenever they identified a hazard and then explaining why they had paused it at that point. Their responses were recorded. Content analysis of responses showed that more experienced drivers reported visibility-related hazards significantly more often than inexperienced ones, and significantly more so at night. They also commented significantly more on hazards related to tight bends in the road and significantly less on hazards concerning compliance with rules. Comments tended to be fewer with higher vehicle speeds, particularly for the least experienced drivers.Results are discussed in terms of how experience-related differences in drivers’ cognitive schemata and mental models are likely to affect hazard perception and crash risk, particularly at night. Some implications for driver training and license testing are suggested.     

Exploring the ability to identify visual search differences when observing drivers’ eye movements

How can we improve learner drivers’ visual skills? Much research has demonstrated that learner drivers have an impoverished spread of search during driving and that this is partly due to lack of knowledge of where and when to look, rather than simply an issue of cognitive load. Several training interventions have tried to improve scanning in these drivers with limited success. We propose that exposing drivers to examples of good and bad scanning behaviour may prove to be a useful tool in training visual search. The success of this approach, however, requires drivers to be able to distinguish between examples of good and bad scanning. To this end, two studies were undertaken where video clips of simulated driving with an overlaid eye movement trace were presented to participants who had to judge whether the eye movements were that of a learner driver or a driving instructor. Overall, participants found this discrimination task very difficult. However, the findings suggested that novice and learner drivers were able to correctly classify those eye movement traces of other learner drivers better than chance. It was also demonstrated that the ability to distinguish between the eye movements of learner drivers and driving instructors improved as the number of objective differences between the two groups increased across specific scenarios (as determined by frame-by-frame analysis using a priori categories). The results suggest that, under certain situations, drivers can extract information about the appropriateness of a particular scanning strategy just by watching a video of the eye movement trace. The implications for training interventions are discussed.     

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.     

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.     

Stressful experiences of first year students of selected universities in South Africa

When students come into the university and become members of the institution for the first time they usually face a number of adjustment problems, the result of stressful experiences they are subjected to by the conditions, events, or situations in their new environment. This study was, therefore, an attempt to find out the nature of students' experiences by finding out aspects (conditions and or events) of the university they assessed as stressful especially during their early days in the university. A 40-item questionnaire, with statements clustered into five categories of stress-induced factors of university, was used to collect relevant data. The subjects responded to the questionnaire in terms of their assessment of their experiences of the different aspects of the university presented to them on the questionnaire. The results revealed that factors associated with Financial Difficulties, Demands of the University Environment and the University Administrative Process (in that descending order) were assessed as stressful. While data analysis revealed significant sex differences in the assessment of stressful experiences with various aspects of the university, no significant differences were found on the basis of subjects' age groups and institutional affiliations.