Cognitive and personality characteristics of worriers

Worriers and nonworriers from a college population were compared on the Imaginal Processing Inventory, the Self-Consciousness scale, and the Sandler-Hazari Obsessionality Inventory. Subjects from both groups also engaged in either brief relaxing or stressful imagery. Before the imagery task, measures of cognitive activity were obtained from periods of relaxed wakefulness, focused attention and anagram performance. After the imagery task, focused attention and anagrams measures were repeated. Worriers reported a more negative daydreaming style, greater difficulty with attentional control, and greater obsessional symptoms, public self-consciousness and social anxiety. On thought sampling measures obtained during relaxed wakefulness periods and rated by objective judges, and on self-report measures obtained during the focused attention task, worriers evidenced significantly more negatively affect-laden cognitive intrusions. No differences were found on anagram performance, and imagery condition did not influence any measure, suggesting that instructed fear images are insufficient to initiate worrisome episodes.     

Impacts of delayed feedback on eco-driving behavior and resulting environmental performance changes

Several ways have been developed and applied to improve the environmental footprint of road transportation while contributing to a better road efficiency and safety. However, independently of these measures, the individual’s behavior as a commuter and/or as a driver is also a major issue that cannot be ignored. As a result, the aim of this paper was to assess the impacts of delayed feedback on driving performance considering indicators such as average speed, excess speeding, extreme braking and acceleration; fuel consumption and CO₂ emissions, among others. Data on driving behavior was collected over a period of 6 months through the use of an on-board device installed in 40 light-duty vehicles in the region of Lisbon, Portugal. Two driving monitoring periods of 3 months each were considered: without feedback (Phase 1) and with feedback (Phase 2). Additionally, the short-term (weekly and bi-weekly) impact of feedback on performance was also assessed.The major findings indicate that both experimental and control groups increased fuel consumption and CO₂ emissions over 5%. Both male and female drivers presented increases in these indicators with female drivers presenting higher values (up to 8%, as opposed to the 4% presented by male drivers). These results are related with increases in the number of accelerations, idling and number of small trips (below 2 km) between monitoring periods. Regarding the immediate impact of feedback on driving behavior, results indicate that when receiving negative feedback (revealing a performance decline), behavior would improve the following week. The opposite was found for positive feedback, with drivers worsening performance after being informed they had improved the previous week. Such findings might give an indication that people react differently to the feedback provided, and might depreciate the information provided when negative results are reached.     

A comparison of the effects of posted feedback and increased police surveillance on highway speeding

A counterbalanced, reversal design was used to compare the effectiveness of posted feedback and increased police surveillance in reducing speeding on two urban highways. Drivers' speeds were measured using a concealed radar unit. During public posting, a large highway sign, which listed the percentage of drivers not speeding during the preceding week and the best record to date, was erected on each street. Use of the feedback sign alternated with periods of baseline and periods of increased police surveillance and ticketing. During increased police surveillance, highly visible, stationary police radar patrols were established along the highways for either 30 min or 60 min per day, 5 days per week. Results indicated that although public posting was highly effective in reducing the percentage of speeding drivers, increased police surveillance was not. Thus, since the feedback sign required only 30 min per week to maintain, public posting was at least 10 times more efficient in controlling speeding than was police surveillance and ticketing.     

Field operational test of a seatbelt reminder system: Effects on driver behaviour and acceptance

The long-term effects on driver behaviour and acceptance of a seatbelt reminder system were examined in an on-road study. The system was capable of detecting seatbelt use in all seating positions and produced a two-stage visual and auditory warning if occupants were unrestrained. The effects of this system were evaluated alone and in combination with two other intelligent transport systems: intelligent speed adaptation and a following distance warning system. Twenty-three fleet car drivers drove an instrumented vehicle (SafeCar) for at least 16,500 km as part of their everyday driving. The results revealed that driver and passenger interaction with the seatbelt reminder system led to large and significant decreases in the percentage of trips where occupants were unbelted, in the percentage of total driving time spent unbelted, and in the time taken to fasten a seatbelt in response to system warnings. The seatbelt reminder system was rated by drivers as being useful, effective and socially acceptable, and led to a decrease in drivers’ subjective workload. These results were found even though the baseline pre-exposure seatbelt wearing compliance rates among participants were high.     

Timeout duration and the suppression of deviant behavior in children

The effects of three different timeout durations were investigated in a group of 20 retarded, institutionalized subjects. Each subject received 1, 15, and 30 min of timeout in a design that was counterbalanced in terms of the order in which timeout durations were presented. Displays of deviant behavior-such as aggression, tantrums, and self-destruction-were followed by periods of isolation in a timeout room. A reversal design was employed such that return-to-baseline periods were instituted after each timeout period. The overall effect of timeout was to reduce significantly the rate of deviant behavior. On the average, 15 and 30 min produced a 35% decrease in deviant behavior with little difference between the effectiveness of 15 and 30 min. The range of effects in all timeout conditions varied widely. The sequence in which the 1-min duration was presented effected the direction of its effect. When it preceded the use of longer durations, 1 min was most effective. As it came later in the sequence, its suppressive characteristics became less reliable.     

Duration, time constant, and decay of the linear motion aftereffect as a function of inspection duration

Subjects rated the strength of the motion aftereffect (MAE) produced by the upward motion of a horizontal grating in two experiments. Inspection periods ranged from 30 to 900 sec in Experiment 1 and from 20 to 120 sec in Experiment 2. A minimum of 22 h elapsed between trials. The decay time constant increased as the square root of the inspection duration for values between 1 min and 15 min of inspection. The ratings suggested that the MAEs consisted of three phases: an initial maximum-strength phase, a decay phase, and a tail. The duration of all three phases increased and the decay rate decreased with increasing inspection duration over the entire range. The results indicate that duration, time constant, and decay rate are not fixed properties of the motion-processing channels in the visual system.     

“I need to skip a song because it sucks”: Exploring mobile phone use while driving among young adults

BackgroundMobile phone use while driving is a well-recognized area of concern. However, while texting/calling among young adult drivers has received much research attention, more research is needed regarding other phone functions used by young adults while driving.Study aimTo explore mobile phone functions used by young adult drivers while driving.ResultsAn online survey of 17–24 year old drivers (N = 612; 428 females) and focus groups with drivers aged (N = 18; 8 females) revealed that mobile phone use while driving was a very common behavior, with more full licence drivers compared with Learner/Provisional drivers using their phone to make/answer calls, send/read text messages and for internet browsing. This nature of mobile phone use while driving was varied, with phones commonly used for entertainment (e.g., to play music), to connect with others (via texting and/or voice calls) and for navigation.Concluding remarksYoung adults use a variety of functions on their phone while driving. It is important that young driver-targeted intervention efforts acknowledge that multiple functions of the mobile phone are used during the drive and it serves multiple purposes. Examining the inhibitors and facilitators of mobile phone use and its various functions while driving is needed, in addition to elucidating if the usage of particular mobile phone functions is similar across different driver cohorts.     

Increasing seat belt use in service vehicle drivers with a gearshift delay

This study evaluated a device that prevents drivers from shifting vehicles into gear for up to 8 s unless seat belts are buckled. Participants were 101 commercial drivers who operated vans, pickups, or other light trucks from the U.S. and Canada. The driver could escape or avoid the delay by fastening his or her seat belt before shifting out of park. Unbelted participants experienced either a constant delay (8 s) or a variable delay (M = 8 s). A 16‐s delay was introduced for those U.S. drivers who did not show significant improvement. Seat belt use increased from 48% to 67% (a 40% increase) for U.S. drivers and from 54% to 74% (a 37% increase) for Canadian drivers. The fixed delay was more effective for U.S. drivers than the variable delay, but there was no difference between these two delay schedules for Canadian drivers. After the driver fastened his or her seat belt, it tended to remain fastened for the duration of the trip.     

Road-sign utility as judged by drivers with different amounts of driving experience

This study starts from the hypothesis that sign perception depends on the motivational valences of signs. Two groups of drivers with different amounts of driving experience rated Swedish road signs on dimensions assumed to indicate perceived sign utility. The ratings were performed against a scenario that included traffic officials' intentions to simplify the sign system. One dimension was amount of reduction in frequency of occurrence; subjects indicated percentages of reduction they believed to be reasonable. A second dimension was appropriateness of complete elimination of a sign from the traffic environment; subjects rated the degree to which elimination was reasonable. Subjective frequency of sign occurrence was rated last. Construct validation procedures showed strong correlations between reduction and elimination ratings only for the higher-experience group. Contrary to expectation, both groups showed the same high level of positive attitudes toward all signs. As expected, frequency was a judgmental base for utility, though weakly, except for permissive signs. It was more extensively related to utility for the higher-experience group, particularly for percentage ratings. Curvilinear relationships obtained between frequency and utility for permissive and road guidance signs.     

Velocity versus safety: Impact of goal conflict and task difficulty on drivers’ behaviour,feelings of anxiety,and electrodermal responses

This paper proposes a goal conflict model that links drivers’ conflicting motivations for fast and safe driving with an emotional state of anxiety. It is proposed that this linkage is mediated by a behavioural inhibition system (Gray & McNaughton, 2000) affecting drivers’ mood, physiological responses and choice of speed. The model was tested with 24 male participants, each of whom undertook 18 runs of a simple driving simulation. On each run, the goal conflict was induced by time pressure and the advance warning of a possible encounter with a deer. The conflict’s intensity varied depending on the magnitude of the equally-sized gain and loss assigned to early arrival and collision respectively. Results show that the larger the conflict, the more slowly the participants drove. In addition, they rated themselves as being more anxious, attentive, and aroused. An increase in task difficulty induced by low visibility resulted in an additional speed reduction and increase in self-reported anxiety but did not lead to a further increase in self-assessed attention and arousal. Overall, the number of electrodermal responses depended neither on conflict nor on task difficulty, but increased linearly with conflict during low visibility. Implications for the incorporation of goal conflict into theories on driving behaviour and conclusions for traffic safety policies are discussed.     

Driver distraction based lane-keeping assistance

Driver assistance systems could be much more effective, if they were adaptive to the driver’s state. Following the idea of a lane-keeping assistance system, which is adaptive to the use of in-vehicle information systems (IVIS), two field experiments were conducted. The first experiment concerned the influence of typical IVIS tasks on lane-keeping. Most IVIS tasks increased the lateral deviations, but in the majority of cases the drivers were still able to stay in their lane.The second experiment concerned two questions: (1) how much lateral support would be needed and (2) how drivers accept this kind of support. The results show that all lateral support algorithms increased the lane-keeping performance with the algorithms providing a higher amount of assistance proving the most useful. All assistance systems were rated as helpful and were considered to increase driver safety, both by the drivers who did not have problems in lane-keeping without assistance.In light of these results an adaptation of a lateral support system to the IVIS-use seems to be useful and worthwhile.     

What Do People Think About the Risks of Driving? Implications for Traffic Safety Interventions1

Two studies found that people generally think of themselves as better than average drivers. Both older and younger people rated themselves slightly better than peers, with the younger people rating their peers as the worst drivers but rating themselves as if they did not belong to this group. University students rated their peers as being more similar to themselves than did nonuniversity younger people. A factor analysis found five dimensions along which people thought about driving risks: environmental and road conditions, unexpected events, driver problems, necessary or unavoidable driving risks, and voluntary driving risks. Speeding was thought of in two ways, as both an unavoidable driving risk and as a voluntary risk. Differences were found between general and specific questions, and a theoretical framework for exploring these in future research was proposed predicts differences between a situational or dispositional focus. The implications of the results for traffic safety interventions were drawn out, and specific recommendations, made for targeting such interventions.     

Bias in older adults’ driving self-assessments: The role of personality

A convenience sample of 50 older drivers (M_age = 73.14, SD = 4.85) completed the Myers-Briggs Type Indicator® (MBTI®) Step III™ instrument and rated their own driving abilities (compared to all other drivers, same age drivers, and their own driving 20 years prior) and their ability to perform 68 specific driving-related behaviors. Each subject’s driving performance was also evaluated in a comprehensive on-road assessment conducted by a certified driving rehabilitation specialist, who rated the same 68 driving behaviors as well as driving performance. Drivers identified by the MBTI Step III instrument as Extraverted, Sensing, and (above median) Confident rated their driving significantly more favorably than Introverts, Intuitives, and below median Confidence drivers. Step III Sufficiency scales were associated with on-road performance: drivers with scores indicating low Confidence, low Stamina, or critical high levels of Compensatory Strain received significantly lower evaluations. Drivers with a Sensing preference or critical Strain score rated their driving significantly more favorably than evaluators did. These findings present preliminary evidence for the utility of personality assessments in identifying self-serving bias in driving self-evaluations, essential for safe self-regulation of driving.     

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.     

Increasing following headway with prompts, goal setting, and feedback in a driving simulator

We evaluated the effects of prompting, goal setting, and feedback on following headway of young drivers in a simulated driving environment and assessed whether changes produced in following headway were associated with reductions in hard braking when drivers were and were not using cell phones. Participants were 4 university students. During baseline, drivers spent half of the time talking on cell phones while driving. At the start of the intervention, drivers were prompted to increase following headway while on the cell phones and were provided a specific target for following headway. Drivers were given feedback on increasing following headway when on cell phones at the end of each session. The intervention package was associated with an increase in following headway and a decrease in hard braking when participants were on and off the cell phones. Cell phone use did not affect any of the measures.     

Advanced driver assistance systems (ADAS): Demographics,preferred sources of information,and accuracy of ADAS knowledge

Advanced driver assistance systems (ADAS) in passenger vehicles can improve highway safety. ADAS place powerful, yet imperfect, automation in the hands of drivers who hold both misconceptions and reservations about ADAS. There is little previous research on drivers’ knowledge of ADAS, and even less on sources of information drivers use to inform their knowledge. The present study addressed this gap, testing hypotheses about influences on understanding of seven ADAS in 634 licensed US drivers (aged 18–82). Multiple regression to predict self-assessed driver characteristics revealed: (a) Drivers who rated themselves as more technically sophisticated tended to be young and male, to be at once less objectively knowledgeable and more confident of their knowledge of ADAS, to avoid car dealers for ADAS information, and to value brand status; (b) Drivers who rated themselves as faster to adopt new technology also tended to be male but to be more objectively knowledgeable about ADAS and to prefer learning about ADAS from owner manuals; (c) Drivers who rated themselves as more confident in using novel vehicle technology tended to be young males with greater objective knowledge of ADAS who valued “hands-on” ADAS experience; (d) Drivers who rated themselves as more concerned about vehicle safety tended to be female, to value crash data, and to rely on hands-on experience to learn about ADAS; (e) Drivers who rated themselves as having greater aesthetic concerns tended to rely on information on styles, colors, wheels when buying a new car and preferred specific ADAS components. Neither of the latter two differed in objective ADAS knowledge. These results make a novel contribution in revealing how driver demographics and characteristics are related to preference for specific sources of information on ADAS and objective knowledge of ADAS. These results can inform future efforts to increase driver understanding of the capabilities and limitations of ADAS and hence increase public safety.     

Drivers' use of hand-held mobile phones in Western Australia

Using a hand-held mobile phone whilst driving has been linked to an increased risk of being involved in a road crash. Little research, however, has been done on actual road exposure rates to this potential safety problem. The main aim of this study was therefore to establish the number of drivers who use hand-held mobile phones while driving, and to discover if this number had increased as compared to similar observations obtained one year earlier. 40 roadside observations were made at major roads during daylight hours. On average approximately 1.5% of all vehicle drivers were observed using hand-held mobile phones. No significant difference was found between the percentage of drivers observed to be using phones in an earlier study and this current study. In addition, separate observations were undertaken at four sites at four periods of the `normal' working day to establish if a possible time of day effect existed. The data found that the level of mobile phone use did not significantly differ during the day, however, as a percentage of vehicle flow, the highest use period was between 11.00 and 12.00. Finally, for the same four sites, supplementary measures were taken to establish personal characteristics of the phone users. It was found that phone users were predominantly male (78%) and less than 40-years old (64%).     

A strong test of exposure effects

A strong test of exposure effects was made by eliminating confounding demand characteristics through the use of a between-subject design. Each subject viewed novel stimuli at a single frequency level, and then rated them on several affective scales. Frequency of stimulus exposure was systematically varied across subjects. Stimuli were rated more positively with increasing exposure, despite the fact that subjects were unaware of any differences in exposure frequencies, and clearly unable to identify the experimental hypothesis. An awareness of the relationship between repeated exposure and affect was thus shown to be an unnecessary condition for the occurrence of exposure effects.