Gender and age-related differences in attitudes toward traffic laws and traffic violations

The study examined gender and age-related differences in drivers’ normative motives for compliance with traffic laws and in gain–loss considerations related to driving. Two age groups of male and female students, totaling 181 respondents, completed a questionnaire measuring several normative motives for compliance with traffic laws, perceived gains and danger involved in the commission of traffic violations, and the frequency of committing various driving violations. The results show that younger drivers and male drivers express a lower level of normative motivation to comply with traffic laws than do female and older drivers. The lowest level of perceived importance of traffic laws relative to other laws was found among young male drivers. The commission of traffic violations was found to be related more to the evaluation of traffic laws among men and younger drivers, compared to women and older drivers. The perceived danger involved in the commission of a driving violation, however, was found to constitute much more of a factor among women than among men before the commission of traffic violations. Perceived gains involved in the commission of violations were more strongly pronounced among older drivers than among younger drivers. Results are discussed concerning different types of attitude–behavior relationships in the context of driving.     

Estimation of the Coefficient of Variation with Minimum Risk: A Sequential Method for Minimizing Sampling Error and Study Cost

The coefficient of variation is an effect size measure with many potential uses in psychology and related disciplines. We propose a general theory for a sequential estimation of the population coefficient of variation that considers both the sampling error and the study cost, importantly without specific distributional assumptions. Fixed sample size planning methods, commonly used in psychology and related fields, cannot simultaneously minimize both the sampling error and the study cost. The sequential procedure we develop is the first sequential sampling procedure developed for estimating the coefficient of variation. We first present a method of planning a pilot sample size after the research goals are specified by the researcher. Then, after collecting a sample size as large as the estimated pilot sample size, a check is performed to assess whether the conditions necessary to stop the data collection have been satisfied. If not an additional observation is collected and the check is performed again. This process continues, sequentially, until a stopping rule involving a risk function is satisfied. Our method ensures that the sampling error and the study costs are considered simultaneously so that the cost is not higher than necessary for the tolerable sampling error. We also demonstrate a variety of properties of the distribution of the final sample size for five different distributions under a variety of conditions with a Monte Carlo simulation study. In addition, we provide freely available functions via the MBESS package in R to implement the methods discussed.     

Auditory localisation of conventional and electric cars: Laboratory results and implications for cycling safety

When driven at low speeds, cars operating in electric mode have been found to be quieter than conventional cars. As a result, the auditory cues which pedestrians and cyclists use to assess the presence, proximity and location oncoming traffic may be reduced, posing a safety hazard. This laboratory study examined auditory localisation of conventional and electric cars including vehicle motion paths relevant for cycling activity. Participants (N = 65) in three age groups (16–18, 30–40 and 65–70 year old) indicated the location and movement direction (approaching versus receding) of cars driven at 15, 30 and 50 km/h in two ambient sound conditions (low and moderate). Results show that low speeds, higher ambient sound level and older age were associated with worse performance on the location and motion direction tasks. In addition, participants were less accurate at determining the location of electric and conventional car sounds emanating from directly behind the participant. Implications for cycling safety and proposals for adding extra artificial noise or warning sounds to quiet (electric) cars are discussed.     

Investigations into pedestrian crossing choices on Cape Town freeways

South Africa is regularly identified in international literature as one of the countries with the highest number of traffic deaths per capita. Of these, around one third are pedestrians. Freeways constitute one of the highest risk locations for pedestrians – in most developed countries pedestrians are not seen in such locations, but for many South African pedestrians freeways are a regular part of their commute. Walking alongside and crossing of freeways are extremely common – and deaths associated with such activity also tragically so. Over the past four years in the Cape Town area alone there have been 413 pedestrian crashes causing 139 pedestrian deaths on freeways, as well as an unrecorded number of serious injuries.While pedestrian crossing behaviour has been extensively researched in many parts of the world, almost none has so far been carried out in the context of freeways. Little is known about pedestrian crossing decisions in locations where the stakes are so high.Following a study using traffic cameras associated with the Freeway Management System to measure the frequency and location of pedestrians crossing freeways, this article reports on surveys into crossing decisions of pedestrians on Cape Town’s freeways. Two successive surveys were conducted with pedestrians on or alongside the freeway. These included pedestrians who crossed using footbridges, and pedestrians who crossed at grade.In the analysis it was clear that while some of the traditional factors such as time saving and convenience were considered, far more important to pedestrians were issues of safety. Safety from fast-moving vehicles was one factor, while safety from criminals was a second and often conflicting factor which affected crossing choices. Crossing at grade was partly described in terms of utility maximisation (time and distance saving) but it was also, for many, one way of avoiding becoming a victim of crime. In terms of their perceptions of being involved in crashes, at-grade crossers reflected an astute awareness of the risks that they face. Many pedestrians articulated the belief that their choice of crossing was constrained by lack of alternatives. Until public transport and safe crossing locations are provided for these pedestrians it is clear that many will continue to cross dangerous roads, in full awareness of the risks they face.     

A simulator study of factors influencing drivers’ behavior at traffic lights

Drivers’ reactions to changing traffic lights have an impact on safety at intersections. We examined the influence of transient factors – more specifically time pressure and social context, both conducive to traffic-light violation – on behavior behind the wheel when a traffic light changes. We carried out an experiment on a driving simulator. The participants were 94 car drivers (53 males) with a mean age of 21.7 years. They drove under time pressure vs. no time pressure. At several intersections the participants were alone (no other drivers present), whereas at several other intersections they were behind a line-up of vehicles, the last of which ran the yellow light (other drivers present). As expected, time pressure and social context (presence of other drivers) increased participants’ risky behaviors while approaching, and going through traffic lights, as well as undesirable rapid accelerations when the signal changes to green. The effect of time pressure on yellow-light running was not mediated by approach speed, which showed that participants in a hurry were likely to run lights intentionally. The results are interpreted in view of proposing effective measures for reducing yellow-light running and rapid accelerations at traffic lights.     

Is gaze behaviour in a laboratory context similar to that in real-life? A study in bicyclists

Numerous laboratory-based studies recorded eye movements in participants with varying expertise when watching video projections in the lab. Although research in the lab offers the advantage of internal validity, reliability and ethical considerations, ecological validity is often questionable. Therefore the current study compared visual search in 13 adult cyclists, when cycling a real bicycle path and while watching a film clip of the same road. Dwell time towards five Areas of Interest (AOIs) is analysed. Dwell time (%) in the lab and real-life was comparable only for the low quality bicycle path. Both in real-life and the lab, gaze is predominantly driven towards the road. Since gaze behaviour in the lab and real-life tends to be comparable with increasing task-complexity (road quality), it is concluded that under certain task constraints laboratory experiments making use of video clips might provide valuable information regarding gaze behaviour in real-life.     

The effect of fatigue driving on car following behavior

Existing fatigued driving analysis methods mainly focus on lateral driving performance by using the measurements related to the steering wheel or lane position. There is a lack of research on longitudinal car following behavior. In this study, 40 professional drivers are invited to participate in field expressway driving experiment, lasting at least for 6 h. During the test, their performance is measured in terms of their self-reported fatigued driving level according to the Karolinska Sleepiness Scale (KSS), the PERcentage of eye CLOSures (PERCLOS) and the Time Headway (THW). Then the effects of the fatigued driving level on car following behavior are evaluated. The results indicate that the fatigue level (for both KSS and PERCLOS) has significantly impact on THW parameters, including the mean, standard deviation and minimum THW. An increase in KSS and PERCLOS leads to a lower mean and minimum THW. Meanwhile, the standard deviation of THW increases with the increase of KSS and PERCLOS. In conclusion, this study found that a higher fatigue level leads to the driver keeping a smaller THW when following another vehicle and choosing shorter THW to make lane change. More deviation of car following performance was also found with the increase of fatigue level. Therefore, the findings of this study can be used to explain fatigue as one of the major reasons for rear-end collisions. Also, the research findings demonstrate the impact of fatigue on driving behavior in terms of car following performance, which can be used as a measurement for monitoring fatigued drivers.     

The role of traffic law enforcements in the relationship between cultural variables and traffic fatality rates across some countries of the world

The aims of the present study were to investigate whether cultural variables are related to law enforcements as well as traffic fatality rates and to examine the role of law enforcements of five risk factors for road safety (i.e., national speed law, national drink-driving law, national motorcycle helmet law, national seat-belt law, and national child restraint law) in the relationship between cultural variables and traffic fatality rates across countries of the world. The aggregated data of the study included Hofstede’s cultural dimensions, Schwartz’s value dimensions, law enforcements of five risk factors for road safety, gross national income per capita, and traffic fatality rates for 97 countries of the world. The results showed that most of the cultural variables were associated with law enforcements of five risk factors for road safety and traffic fatality rates of countries. By bootstrapping, among Hofstede’s cultural dimensions, it was found that the indirect effects of long-term orientation (LTO) on fatality rates (FR) through speed, helmet, and child restraint enforcements were significant, separately. Among Schwartz’s value dimensions, the indirect effects of embeddedness on fatality rates through speed and child restraint enforcements were significant, separately. Intellectual autonomy had also significant indirect effects on fatality rates via speed and child restraint enforcements, separately. Finally, it was found that the indirect effects of affective autonomy on fatality rates through speed and helmet enforcements were significant, separately.     

Revisiting self-regulatory techniques to promote physical activity in older adults: null-findings from a randomised controlled trial

Objective. A randomised controlled trial (RCT) was conducted to evaluate a three-hour face-to-face physical activity (PA) intervention in community-dwelling older German adults with four groups: The intervention group (IG) received behaviour change techniques (BCTs) based on the health action process approach plus a views-on-ageing component to increase PA. The second intervention group ‘planning’ (IGpl) contained the same BCTs, only substituted the views-on-ageing component against an additional planning task. An active control group received the same BCTs, however, targeting volunteering instead of PA. A passive control group (PCG) received no intervention.

Design. The RCT comprised 5 time-points over 14 months in N = 310 participants aged 64+.

Main outcome measures. Self-reported as well as accelerometer-assessed PA.

Results. Neither PA measure increased in the IG as compared to the other groups at any point in time. Bayes analyses supported these null-effects.

Conclusion. A possible explanation for this null-finding in line with a recent meta-analysis is that some self-regulatory BCTs may be ineffective or even negatively associated with PA in interventions for older adults as they are assumed to be less acceptable for older adults. This interpretation was supported by observed reluctance to participate in self-regulatory BCTs in the current study.