Effects of route guidance variable message signs (VMS) on driver behaviour

Effects of route guidance Variable Message Signs (VMS) on speed and route choice were investigated in a field study on two sites on motorways. Two VMS were used in the study, which displayed information about a closed road section downstream on the motorways and recommendations for alternative routes. Route choice, speed and braking behaviour were compared between vehicles approaching the VMS while they displayed messages and while they were left blank without message. There was high compliance with the messages on the VMS. About every fifth vehicle changed route choice according to the recommendation, and almost none drove as far as the closed road section. Speed measurements of 3342 vehicles showed large speed reductions, and video observations showed that large proportions of vehicles braked while approaching the VMS. The speed reductions and braking manoeuvres can partly be attributed to attention overload or distraction due to the information on the VMS. However, a proportion of the speed reductions was due to chain reactions where one vehicle braked and forced the following vehicles to brake or change lanes in order to avoid collisions. Safety problems may result directly from distraction, or indirectly from the reactions of the drivers to the distraction.     

A driving simulation study to investigate the information threshold of graphical variable message signs based on visual perception characteristics of drivers

Graphical variable message signs (VMSs) are infrastructure-based advanced traveler information systems widely used to provide drivers with real-time traffic condition information about a road section or area. However, there is a lack of research on the suitable volume of information to be shown on graphical VMSs. In practice, an overload of VMS information commonly exists, especially on China’s highways. Building on our earlier findings obtained through surveys and static cognitive experiments, this study introduces the use of dynamic simulation experiments to assess the influence of the volume of information (i.e., number of roads displayed) on graphical VMSs from the perspective of drivers’ visual perception characteristics. Thirty-two drivers participated in the driving simulation experiment and questionnaires. Five indexes, including legibility speed, legibility distance, legibility time, comprehension accuracy, and driver subjective scoring, were thoroughly analyzed to evaluate their relationships to different volumes of information (i.e., four, five, and six roads shown on a VMS). The results show that the legibility distance notably decreased with increasing volumes of information. The comprehension accuracy decreased significantly when the number of roads shown increased to six. The legibility speed, legibility time, and subjective scoring also deteriorated as the number of roads displayed on the VMS increased. The index scores were evaluated, in combination with the data of the drivers’ subjective scoring, data-based statistical analyses, and comprehensive evaluations using the TOPSIS method, to recommend that five is the recommended maximum number of roads to be shown on a graphical VMS. The results of this study support the goal of providing understandable and effective messages for drivers by addressing issues relating to how much information should be displayed on a VMS. These findings provide a basis for policy development to ensure consistent and practical designs of graphical VMSs on highways.     

Reliability of variable message signs information: A field experiment study in Chongqing

A variable message sign (VMS), which is a key component of intelligent transportation systems, has been frequently used in the management of urban roads and motorways to provide drivers with real-time traffic condition information about a road section or area. Nevertheless, there is a lack of unified regulations for VMS design, which makes it difficult to accurately determine the understandability and legibility of VMS information. In practice, inappropriate designs of VMSs are common, such as overload of VMS information and excessive number of phases, particularly on the urban roads of China. Building on our earlier findings obtained by surveys, in this study, field tests were conducted to assess the reliability of VMS information in terms of the visual perception characteristics of drivers. For a full visual perception, the information displayed on a VMS must be reliable, i.e., it should be easy for drivers to detect, obtain, and understand the messages they require. Two basic theories—information theory and visual perception theory—were introduced to build a quantification model of VMS information, select evaluation indices, and design the experimental process. A total of 24 drivers participated in the field experiments and questionnaires. Five indices—information obtainment rate, periodic validity, driver subjective scoring and the corresponding UI (represents information intelligibility), and CE (represents information legibility)—were analyzed to evaluate their relationships to VMS information reliability. The results confirmed that the amount of information, and the scrolling period considering redundant distance, significantly affect the reliability of VMSs information. For static VMSs, the information obtainment rate and the subjective scoring decrease with increasing amount of information. The recollection accuracy of the drivers significantly declines when the amount of information shown increases to 90 bits, corresponding to an information obtainment rate of less than 0.8 and UI equal to 0. For dynamic VMSs, the information reliability deteriorates as the scrolling period shortens and the number of phases increases. Unreasonable reliability is found when the periodic validity is less than 0.9, i.e., the actual scrolling period is more than 10% less than the calculated one, corresponding to CE equal to 0. The reliability of information was evaluated by combining the subjective scoring of the drivers and a data-based statistical analysis and considering driving safety. Accordingly, it was recommended that 90 bit is the maximum amount of information to be shown on a VMS and that the preferred scrolling period of each phase of a dynamic VMS is 5 s. The results of this study support the objective of providing reliable information to drivers by addressing the problems related to the amount of information and presentation time for VMSs. These findings provide a basis for determining the thresholds for VMS information to promote practical and user-friendly designs of VMSs on urban roads.     

Long-term benefits of prompts to use safety belts among drivers exiting senior communities

Senior drivers are vulnerable to automobile crashes and subsequent injury and death. Safety belts reduce health risks associated with auto crashes. Therefore, it is important to encourage senior drivers to wear safety belts while driving. Using a repeated baseline design (AAB), we previously reported that motivating signs boosted safety belt usage by drivers exiting senior communities from baseline (72% and 68% usage), to postinstallation of signs (94%), to 6 months follow-up (80%). The current study was a 4-year follow-up in which six senior communities, with seat belt signs, were compared to six matched control senior communities with no signs. Safety belt usage was stable, across 4 years, at approximately 80% for both male and female drivers and front seat passengers for the six communities with signs, and was approximately 55% for control sites. These finding suggest that the simple and low-cost intervention of erecting signs to prompt safety belt use has persistent benefits that affect driver and passenger behavior alike.     

Similarities between self-reported road safety behavior of teenage drivers and their perceptions concerning road safety behavior of their parents

The study investigated 401 19-year-olds, who were licensed car drivers in Lithuania. The focus of the survey was on the self-reported road safety behaviors of teenage drivers and their perceptions of their parents’ road safety behaviors, in order to assess behavioral similarities between teenagers and their parents. The survey also investigated whether parents and teenagers discuss issues of driving safely, and whether there is an association between these conversations and driving restrictions.According to teenagers’ reporting, road safety behavior of teenage drivers and their parents often is similar: most of them break the speed limit, drive when feeling fatigued, use a cell phone when driving, and do not fasten the seat belt as a passenger in the back seat. The study indicated that there is a positive moderate correlation between road safety behaviors of teenagers and their parents, as reported by the teenagers. A majority of teenagers report that they discuss road safety factors, driving safely and driving behavior with their parents. Based on teenager reports, the parents, who discuss road safety issues with their children, are more likely to apply restrictions on teenagers’ driving.     

Proactivity towards workplace safety improvement: an investigation of its motivational drivers and organizational outcomes

Initiating a safety oriented change—or safety initiative—is conceptually distinct from other forms of safety participation and safety citizenship behaviour, yet little attention has been given to its performance outcomes or its motivational antecedents. An initial study with a sample composed of middle managers (N = 86) showed that safety initiative predicted objective improvement actions 6 months later, whereas, showing differential validity, safety compliance predicted the implementation of monitoring actions. Two subsequent studies focused on motivational antecedents. First, using a sample of team leaders (N = 295), we tested a higher-order structure of proactive motivation that incorporates three domains: “can do”, “reason to” and future orientation. Second, in a longitudinal study of chemical work operators (N = 188), after checking for the influence of potential confounders (past behaviours; accidents experience; perceived risk), we showed that safety initiative was predicted only by proactive motivation. Instead, safety compliance was found to be associated with affective commitment and scrupulousness, whereas safety helping was found to be associated with affective commitment. Self-reported behaviours were validated against rater assessments. This study supports the importance of distinguishing safety initiative from other safety behaviours, indicating how to create an organizational context supporting a proactive management of workplace safety.     

Behavioral adaptations of human drivers interacting with automated vehicles

Advancements in technology are bringing automated vehicles (AVs) closer to wider deployment. However, in the early phases of their deployment, AVs will coexist and frequently interact with human-driven vehicles (HDVs). These interactions might lead to changes in the driving behavior of HDVs. A field test was conducted in the Netherlands with 18 participants focusing on gap acceptance, car-following, and overtaking behaviors to understand such behavioral adaptations. The participants were asked to drive their vehicles in a controlled environment, interacting with an HDV and a Wizard of Oz AV. The effects of positive and negative information regarding AV behavior on the participants’ driving behavior and their trust in AVs were also studied. The results show that human drivers adopted significantly smaller critical gaps when interacting with the approaching AV as compared to when interacting with the approaching HDV. Drivers also maintained a significantly shorter headway after overtaking the AV in comparison to overtaking the HDV. Positive information about the behavior of the AV led to closer interactions in comparison to HDVs. Additionally, drivers showed higher trust in the interacting AV when they were provided with positive information regarding the AV in comparison to scenarios where no information was provided. These findings suggest the potential exploitation of AV technology by HDV drivers.     

Dimensions of driver anger, aggressive and highway code violations and their mediation by safety orientation in UK drivers

Aggressive behaviour on the roads is reported to be on the increase. This study administered Driving Anger Scale (Deffenbacher et al. (1994). Development of a driving anger scale. Psychological Reports, 74, 83–91.), the Driver Behaviour Questionnaire, and the Driving Skill Inventory to a sample of 270 British drivers. Factor analysis of the Driving Anger Scale items yielded three factors measuring anger generated by the reckless driving, direct hostility and impeded progress by others—contrary to the six subscales found with the original US sample. Younger drivers and low mileage drivers were more likely to exhibit all three types of driving anger, but no differences between male and female drivers were found. In addition, a driver’s safety orientation predicted (negatively) anger evoked by impeded progress and direct hostility whereas self-assessed perceptual-motor skills were positively related to anger generated by impeded progress. Both Highway Code and aggressive violations were significantly related to the anger factors, and, using the procedure by Baron and Kenny (Baron & Kenny (1986). The moderator–mediator variable distinction in social psychological research: conceptual, strategic, and statistical considerations. Journal of Personality and Social Psychology, 51, 1173–1182.), the prediction of violating behaviour (Driver Behaviour Questionnaire) by reported anger was shown to be mediated by the self-assessed safety skill scale but not the perceptual-motor skill scale (Driver Skill Inventory), and moderated by neither. Implications for driver education countermeasures are noted.     

Younger drivers executive functioning and the relationship with experiencing signs of sleepiness

Young drivers are more likely to continue driving when experiencing signs of sleepiness and are over-represented in sleep-related crashes. Adolescence and early adulthood are characterised by comparatively poor executive functioning, and while previous research has demonstrated a link between poor executive functions and several risky driving behaviours, the relationship with sleepy driving is not well understood. Accordingly, the first aim of the current study was to examine the association between executive functions and experiencing the signs of driver sleepiness in a sample of young adult drivers. Additionally, young drivers who have less experience with driving while sleepy, may attribute less importance to the signs of sleepiness as an indicator of underlying sleepiness level. To test this assumption (aim two), the impact of experiencing signs of sleepiness on perceptions of the importance of those signs was examined. Participants included 118 young adults aged between 17 and 25 years, who completed an online survey measuring experiences with the signs of sleepiness while driving, executive functions, and demographic characteristics. This sample of young adults reported having considerable experience with several signs of sleepiness (i.e., yawning, mind wandering, and difficulty keeping eyes while driving). A linear regression analysis found that the demographic variables of age and hours driven per week, as well as the executive function constructs of organization, strategic planning, and impulse control were associated with experiencing signs or sleepiness. Moreover, having experienced more signs of sleepiness was associated with an increased likelihood in rating those signs as important indicators of sleepiness. The current findings suggest both that several high-level cognitive processes as well as levels of experience with driving when experiencing signs of sleepiness contribute to young peoples’ sleepy driving.     

Acquisition and generalization of manual signs by hearing-impaired adults with mental retardation

Behavioral procedures have been used to teach manual communication skills to individuals with mental retardation, although few studies have examined the assessment of generalization of such skills beyond the teaching environment. In this study, we investigated the effectiveness of directed rehearsal for teaching and facilitating the generalization of manual signs by six hearing-impaired adults with mental retardation. The effects of directed rehearsal, alone and combined with positive reinforcement for correct responses, were compared to a no-training control condition in an alternating treatments design. Although directed rehearsal was superior to the no-training control condition in teaching manual signs, the procedure was more effective when combined with positive reinforcement. The combined procedure was used to facilitate the generalization of learned signs across a number of variables. The results showed that there were high levels of generalization by all participants across novel phrases, settings, and trainers but variable levels of generalization to another response mode by some subjects. Further, increased levels in overall vocal communication were found for most participants.     

Effects of personality on driving behaviors among professional truck drivers: The mediating effect of safety climate

Introduction: The number of traffic accidents involving truck drivers remains high, and strategies to eliminate the probability of such accidents have been proposed, among which enhancing the safety climate has attracted much interest. The main purpose of the current study was to validate the Chinese version of the safety climate scale for truck drivers and apply it to investigate the mediating effect of safety climate between truck driver personality and driving behavior. Method: A total of 389 male truck drivers completed the Big Five Inventory, the Chinese version of the trucking safety climate scale, the driver behavior questionnaire and the positive driver behavior scale. Results: The reliability and validity of the Chinese version of the organization-level safety climate scale and the group-level safety climate scale were confirmed through factor analysis. More importantly, a path analysis revealed that the organization-level safety climate mediated the effects of agreeableness and neuroticism on aggressive violations, ordinary violations and lapses, while the group-level safety climate mediated the influences of agreeableness, neuroticism and openness on positive behavior and all four kinds of aberrant driving behaviors. Conclusions: This study introduced the trucking safety climate scale into China and stressed the significance of improving both the organizational and the group levels of safety climate to reduce accidents involving professional truck drivers. Practical Applications: First, the adapted safety climate scale for Chinese truck drivers contributes to further investigating the role that safety climate plays in the safety problem of truck drivers in China. Moreover, the critical impacts of both levels of the trucking safety climate serve as reminders for relevant companies to not only pay attention to establishing an organization-level safety climate but also invest more effort into promoting the group-level safety climate.     

Estimating the safety benefit of separated cycling infrastructure adjusted for behavioral adaptation among drivers; an application of agent-based modelling

Separated cycling infrastructure is a key strategy employed by urban and transport planners to reduce car vs cyclist crashes.We constructed an agent-based model (ABM) to explore the potential effects of introducing progressively greater levels of saturation (e.g., more kms) of separated cycling infrastructure into a transport network in which drivers also demonstrated behavioral adaptation in response to increased exposure to cyclists as suggested by the safety in numbers (SiN) theory.The findings highlight that if behavioral adaptation among drivers is assumed to be a strong mechanism underpinning cyclist safety, the introduction of low levels of separated cycling infrastructure across a network (e.g., few kms) may provide little or no reduction in car vs cyclist crashes. This is due to the countervailing effects that separated infrastructure may have on drivers’ exposure to cyclists; a fundamental contributor to the concept of behavioral adaptation.This study demonstrates the utility of ABMs to explicitly define and model candidate behavioral mechanisms associated with cyclist and vehicle interaction when estimating the interaction of infrastructure and behavioral mechanisms proposed to underlie cyclist safety. Practically, it suggests that greater saturation of separated cycling infrastructure across transport networks may be required to reduce overall car vs cyclist crashes in circumstances where behavioral adaptation is also a strong mechanism contributing to cyclist safety.     

Seeking support: An interpretative phenomenological analysis of an Internet message board for people with Complex Regional Pain Syndrome

In this article, we report on the findings of a qualitative inquiry into how an online message board for people who have Complex Regional Pain Syndrome (CRPS) was used by its members. All messages (and responses) posted on the CRPS message board over a 4-month period were collected retrospectively. The data were analysed using the method of Interpretative Phenomenological Analysis. Members used the message board to seek (and provide) support to those with CRPS, and also to express their emotions, feelings and experiences linked to their condition. The message board provided an important source of support for a patient group that can otherwise become isolated as a result of their mobility problems. Furthermore, the analysis revealed the unrealistic hopes that patients can hold concerning the anticipated outcomes of their treatment. This is an important issue for healthcare professionals to explicitly address when interacting with the patient group.     

Text‐message reminders plus incentives increase adherence to antidiabetic medication in adults with type 2 diabetes

Some adults with Type 2 diabetes mellitus have difficulty adhering to their oral medication regimens. The current study used a multiple baseline design with 3 adults with Type 2 diabetes. Medication taking was monitored remotely in real time via an electronic pill bottle. During the intervention, monetary incentives were delivered contingent on evidence of adherence to taking medication at specified times. Text‐message reminders were also sent if medication was not taken. Adherence increased for all participants. Future studies should separate the relative contributions of text‐message and incentive components of the intervention.     

Model checking propositional dynamic logic with all extras

This paper presents a model checking algorithm for Propositional Dynamic Logic (PDL) with looping, repeat, test, intersection, converse, program complementation as well as context-free programs. The algorithm shows that the model checking problem for PDL remains PTIME-complete in the presence of all these operators, in contrast to the high increase in complexity that they cause for the satisfiability problem.     

Supervisory interpretation of safety climate versus employee safety climate perception: Association with safety behavior and outcomes for lone workers

Research has shown that safety climate predicts safety behavior and safety outcomes in a variety of settings. Prior studies have focused on traditional work environments in which employees and supervisors work in the same location and the mechanisms through which safety climate affects behavior are largely understood. However, the nascent research examining safety climate among lone workers suggests that safety climate may have some uniqueness in this context. Based on leadership theories and utilizing an exploratory approach, this study increases our understanding of the lone worker context by examining employee perception of safety climate and supervisory interpretation of safety climate; how similar or different they are, and how they are related to important safety outcomes. Surveys were administered to a matched sample of 1831 truck drivers and their 219 supervisors at four different trucking companies. Objective data on employee injuries were collected six months after survey administration. The results provided support for the measurement equivalence of the Trucking Safety Climate Scale at the organization level for both employee and supervisor respondents. For both organization- and group-level safety climate, employee perceptions of safety climate and supervisory interpretation of safety climate were significantly different, such that supervisors provided higher ratings for both safety climate sub-scales. Further, only employee safety climate perceptions significantly predicted self-reported safety behavior (directly) and objective injury outcomes (indirectly). This suggests that when trying to gauge and improve upon a trucking company’s safety climate, we should rely on employee perspectives, rather than supervisory interpretation, of safety climate.     

A rational-emotive group intervention for preventing and coping with stress among safety officers

A stress management and prevention workshop for nonclinical industrial workers using rational-emotive principles with 18 months followup is reported. Twenty-two senior safety officers participated in an intervention program of five weekly meetings aimed at improving cognitive skills and assertiveness mainly by decreasing irrational thought processes. We hypothesized an increase in assertiveness, and a decrease in irrational beliefs, and emotional and cognitive stress symptoms (manifested in somatic complaints and cognitive weariness). Assertiveness improved and somatic complaints and irrationality decreased in the short term. Eighteen months later, cognitive weariness was also reduced. The other improvements were still evident, but not to the same extent as short-term effects. Although the workshop improved rationality, further practice would be needed in the behavioral aspect of stress prevention to achieve long-term improvements in assertiveness.Talma Kushnir, Ph.D., is a social and medical psychologist at the Occupational Health and Rehabilitation Institute, Raanana, Israel, and teaches psychology and health promotion at the Tel-Aviv University Medical School.Ruth Malkinson, Ph.D., fellow and RET trainer and supervisor of the Institute for RET, and teaches at the School of Social Work and Medical School at Tel-Aviv University, Israel. Both authors contributed equally to this studyThis study was supported by the Committee for Preventive Action and Research in Occupational Health, The Ministry of Labor and Social Affairs, Jerusalem, Israel.The authors thank Estie Weisberg for her administrative assistance in organizing the workshops.     

Effects of a driver assistance system with foresighted deceleration control on the driving performance of elderly and younger drivers

It is imperative to enhance the safety of elderly individuals on the roads to ensure the quality of their daily life. Near-miss incidents or accidents at blind intersections often result from a conflict between the behaviors of the driver and of other road users (pedestrians and cyclists). The failure to search for potential conflict in the context of blind intersections is a concern pertaining to road safety. The proposed assistance system performs a proactive braking intervention to achieve a referenced velocity in uncertain situations, such as one in which an unobserved pedestrian might initiate a road crossing. The proactive braking intervention attempts to manage the potential risk of crashing with respect to covert hazards. Because an automated system may impair a human’s ability to perceive and respond to hazardous situations while driving, this study was designed to examine the effects of proactive braking intervention and visual support cues on elderly and younger drivers’ ability to respond to information about potentially hazardous situations. We conducted a public-road driving experiment involving 108 elderly and younger drivers from two non-overlapping age groups. It was observed that the vehicle slowdown realized through the proactive braking intervention enabled the drivers to perform safety confirmation near blind spots and caused them to be more sensitive to and wary of potential hazards. This approach could be effective not only for elderly drivers, but also for young or inexperienced ones.     

Electrocortical signs of arousal in response to darkness and the assessment of type A behavior in professional drivers with and without cardiovascular disease

Background and Aims  In night driving, the fatal accident rate is about four times that in daytime. There is a lack of published studies of the effect of darkness on electrocortical responses in professional drivers (PD). Aim: Assessing relations between electroencephalographic (EEG) reactions to enforced darkness reminiscent of night driving, and untoward behavioral response patterns, notably Type A behavior. Methods  PD: 13 with ischemic heart disease, 12 hypertensives (HTN), 10 borderline hypertensives and 34 normotensives, and 23 non-PD controls. Five minutes of electroencephalographic recording with eyes closed, and subsequently 3 minutes exposure to darkness. EEG parameters were: alpha abundance, amplitude and frequent. Type A behavior (TAB) was assessed by observation and by questionnaire. Results  Alpha abundance diminished significantly for darkness compared to spontaneous recording for all groups. No between-group differences were found for EEG. There were no significant differences in EEG between drivers with IHD or HTN taking versus not taking centrally active β-blockers. Drivers with IHD were the only group to show significant increase in dominant α frequency at darkness. The IHD group also had the highest TAB questionnaire scores and the heaviest exposure to professional driving. Type A scores were significantly correlated with dominantt alpha frequency during darkness. Low availability of attachment and special driving hazards best predicted TAB scores in driven. There was a significance between group difference with respect to Symbolic Aversiveness at the work place comparing each driver group with the non-PD control group. Conclusions  Exposure to darkness reminiscent of night driving can elicit central arousal, in conflict with circadian rhythm, and in combination with other driving hazards which contribute to symbolic aversiveness, the essence of driving. And low availability of social attachment could contribute to sustained, and in turn to the development of Type A behavior in professional drivers.     

Changes in dynamic balance control over time in children with and without Developmental Coordination Disorder

The aim of this study was to examine differences in underlying adaptations of dynamic balance in children with and without Developmental Coordination Disorder (DCD) during a Wii Fit game and to measure changes over time and after intervention.Twenty-eight children with DCD and 21 typically developing (TD) children participated in the study. Analyses of force plate variables showed that the TD group initially used a longer path length for the ski slope descent and tended toward more variation in Center of Pressure (CoP) displacement in lateral direction than the children with DCD. In contrast, the TD group showed a trend of fewer reversals per cm in both AP and lateral direction. After the nonintervention period, the TD group improved performance by decreasing the path length, while the DCD group improved by increasing the path length and by decreasing the number of reversals. After intervention, no changes were found in sway characteristics. Individual analyses within the DCD group showed that the path length per run fell more often within the 95% confidence Interval of the faultless runs. In conclusion both TD and DCD children modify the underlying kinetics of dynamic balance control, but in different ways and both lead to better performance.