Sexual activity while driving: A content analysis of media reports

Sexual activity while driving fits the definition of distracted driving because it involves the diversion of attention away from the driving task. However, this risky driving behaviour has received little attention compared to other distracted driving activities. To address the lack of research on sexual activity while driving, the internet was searched from April to June 2020 for media reports in which sexual activities occurred within the cabin of a moving vehicle, taking specific note of: gender, the presence of others, time of day, use of substances, the nature of the circumstances surrounding the incident, and whether crashes had occurred. A total of 106 unique and verified cases were identified from 2004 to 2020. The reports involved 76 male (71.7%) and 30 female drivers (28.3%), and there were 43 (40.5%) serious incidents that involved a crash and 23 fatalities (21.7%). In 17 (16.0%) incidents their vehicle hit another car, and a pedestrian or cyclist was hit in 3 (2.8%) incidents. The risk of a serious incident was higher during oral sex or intercourse than solitary activities (i.e. masturbation). A total of 63 (59.5%) mild incidents (without crashes or fatalities) were identified, in which reports included accounts by witnesses or police regarding sexual activity while driving. Given the potential seriousness of incidents, this topic deserves further research to better understand the prevalence and safety implications of sexual activity while driving.     

Evaluating driver comprehension of the roadway environment to retain accountability of safety during driving automation

Driver comprehension is a substantial component of situation awareness that involves the ability of an individual to understand the significance of an object, traffic sign, or hazard while driving. An increase in crashes related to autonomous driving systems has raised a concern regarding the safety of other roadway users due to the diminishing accountability resulting from a general lack of understanding of the limitations or disregard of the safety protocols by users. To keep drivers vigilant when engaged in partial automated systems, a methodology to monitor real-time driver comprehension was proposed. A driving simulator study consisting of 90 participants, equally split between males and females, was executed to establish driver comprehension in six different variations of driving difficulty. Joint probability density functions were created by considering percent time spent gazing, answers to probe questions, and driving performance. Based on these density functions, five levels of comprehension were devised and assigned thresholds. Overall, as task difficulty increased, a non-linear deterioration in driving speed along with an increase in total gaze duration was observed before comprehension was attained. A two-step validation protocol was also proposed to ensure similar levels of comprehension to non-automated driving from the human driver, when engaged in early forms of automation. The proposed real-time driver comprehension monitoring constitutes a first step toward developing a methodology to reinstate the accountability of safety of other roadway users when engaged in driver-in-the-loop automation systems.     

Student driver propensity to engage with distractions – a self-report survey

This paper reports a survey of engagement with, and ratings of, driver distraction, for undergraduate student drivers. Survey data was collected using an anonymous online questionnaire. 530 respondents contributed to the survey during a seven-year data collection period.Results indicate that the three internal-to-vehicle behaviours rated as most distracting when driving were ‘writing text messages’, ‘internet use’, and ‘reading text messages’. The three most frequently undertaken distractions were, ‘(interactions with) adults’, ‘daydreaming’, and ‘eating, drinking or smoking’. Considering external-to-vehicle distractions, the top three rated were ‘environmental conditions’, ‘unexpected objects or events’, and ‘animals behaving unexpectedly’; while the most frequently experienced external distractions were ‘people (behaving normally), ‘busy roads’ and ‘official signage’. Some evidence was found that internal-to-vehicle distractions were relatively more distracting than external-to-vehicle ones, along with limited findings showing significant variation in the amount of engagement with distractions over time. Significant predictive models for engagement with distraction were calculated (for both work-related and non-work-related driving) and found to be broadly in agreement with previous research, although accounting for less variance in the models. Significantly greater engagement with distractions was found during non-work-related driving, when compared to work-related.The data present a picture of ongoing and substantial engagement with distracting behaviours for this population over the data collection period. For example, on a daily or weekly basis, more than three-fifths of respondents reported willingness to read text messages with the vehicle in motion; while just under half indicated that they typically write text messages in the same circumstances. However, the findings do offer some promise that interventions targeted towards non-work-related driving behaviours may be effective to reduce volitional engagement with distractions.     

From sport to eco: A case study of driver inputs on electric vehicle efficiency

This study focuses on driver-induced changes to vehicle energy and emissions performance by altering drivetrain configurations. It defines and examines the motivations for the use of drive modes in plug-in hybrid electric vehicles (PHEVs). Drive modes are defined as user-selectable drivetrain configurations that allow drivers to change vehicle performance aspects such as altering its propulsion status from electric to gas, changing the steering responsiveness, suspension stiffness, and regenerative braking strength. Despite the direct impact they have on the vehicle’s energy usage, greenhouse gas emissions, and local air emissions, the impact of drive modes are not traditionally measured as part of the vehicle’s performance and certification tests. The impact of drive mode choice can explain a portion of the discrepancy between PHEVs expected and on road performance as a recent study by the authors found that the use of certain modes can result in a 15–30% increase in total energy usage in a vehicle traveling at freeway speeds.This is the first study to examine the motivations for the use of these drive modes and provides an overview of PHEV drive modes, classifying them into two main mode categories (propulsion adjustment and driver experience) and eight different mode types based on their intended purpose. This is followed by a logistic regression of 11 indicators for mode usage taken from a survey of over 4,500 PHEV owning households, showing that gender and the number of long-distance trips were the most commonly associated with usage across mode types.     

The safety and conspicuity of pedestrian crossing at roundabouts: The effect of median refuge island and zebra markings

Roundabouts are one of the most used road intersections because, compared to signalized ones, they reduce conflict points between traffic flows and moderate driving speed. Great attention should also be paid to vulnerable road users at roundabouts. According to accident statistics, in fact, accessibility of pedestrians and cyclists is not always ensured.This paper has evaluated the effects on the visibility of pedestrian crossing before and after the displacement of zebra markings, moved before intersections, and the introduction of media refuge islands and “Yield here to pedestrians” vertical signs. The above effects have been assessed by before-after analysis of speed and visual behaviour of drivers approaching the crosswalk.Moreover, the analysis of the drivers’ eye movements has highlighted the most salient elements of the pedestrian crossing. The relation between the drivers’ visual behaviour and the vehicle speed have also been calculated. Results have confirmed that the intervention carried out has increased both visibility and safety of the studied pedestrian crosswalks.Zebra markings and the median refuge island have turned out to be the most glanced elements, respectively seen by 93.75% and 56.25% of the drivers, followed by the “Yield here to pedestrians” vertical sign. The mean distance of first fixation of the crosswalk increased from 21.98 m before the intervention, to 40.69 m after it. The drivers perceived the pedestrian crossings from a longer distance after the intervention, and they continued to glance at the crosswalk while approaching it, enhancing their visual attention.     

Contributory factors to sleepiness amongst London bus drivers

Driver sleepiness contributes to a substantial proportion of all road crashes. Despite all that is known about driver sleepiness, bus drivers are often overlooked. What is certain is that bus drivers have the potential to suffer from sleepiness as they are shift workers. The current research used a large online survey to investigate sleepiness amongst London bus drivers. There were two aims; to quantify the prevalence of sleepiness amongst London bus drivers, and to determine the factors which contributed to sleepiness. Overall, 20.8% of respondents indicated that they had to fight sleepiness at least 2–3 times a week, and 36.6% of respondents stated that they had experienced a close call due to sleepiness in the past year. There were several potential causes of sleepiness including work, sleep, and personal factors such as obtaining less than 11 h rest between shifts, working 6 or more days without a rest day, and poor self-reported health. These findings show that sleepiness is common amongst London bus drivers and is caused by a combination of factors. The combination of contributory factors suggests that a multifaceted approach should be taken to reduce bus driver sleepiness.     

The effect of sleep-need and time-on-task on driver fatigue

Both sleep- and task-related factors are thought to contribute to driver fatigue, with each factor individually associated with deteriorated driving performance. However, the relative and combined effects of these factors in the context of monotonous driving have not been well studied. This study (N = 60) investigated lateral and longitudinal vehicle control, subjective fatigue and physiological response (EEG) during three 10-minute periods of time-on-task spread across a monotonous, 2-hour simulator drive. Level of physiological sleep-need was manipulated between participants by varying the instructed time spent in bed on the night before testing (≤5h or ≥ 8 h). In addition, half of the participants in each sleep group read the applicable speed limit from periodic roadside signs whereas the others performed an arithmetic calculation, displayed on the signs, to determine the speed limit. This task manipulation has been demonstrated to reduce performance decrements over time. Results demonstrated effects of time-on-task and sleep need on self-report ratings, an effect of time-on-task on EEG indices, and an interaction of sleep-need and time-on-task on an EEG index of mental workload and on the lateral control measure of driving performance. There were no significant effects on the measure of speed variability. These results confirm that both sleep-need and time-on-task negatively affect driver state, and that time-on-task decrements in driver performance can occur in the absence of heightened sleep-need. Results also suggest that drivers with heightened sleep-need could protect their performance for a short time, perhaps by exerting effort to compensate for reduced capacity. The secondary task did not counteract declining performance.     

On-to-off-path gaze shift cancellations lead to gaze concentration in cognitively loaded car drivers: A simulator study exploring gaze patterns in relation to a cognitive task and the traffic environment

Appropriate visual behaviour is necessary for safe driving. Many previous studies have found that when performing non-visual cognitive tasks, drivers typically display an increased amount of on-path glances, along with a deteriorated visual scanning pattern towards potential hazards at locations outside their future travel path (off-path locations). This is often referred to as a gaze concentration effect. However, what has not been explored is more precisely how and when gaze concentration arises in relation to the cognitive task, and to what extent the timing of glances towards traffic-situation relevant off-path locations is affected. To investigate these specific topics, a driving simulator study was carried out. Car drivers’ visual behaviour during execution of a cognitive task (n-back) was studied during two traffic scenarios; one when driving through an intersection and one when passing a hidden exit. Aside from the expected gaze concentration effect, several novel findings that may explain this effect were observed. It was found that gaze shifts from an on-path to an off-path location were inhibited during increased cognitive load. However, gaze shifts in the other direction, that is, from an off-path to an on-path location, remained unaffected. This resulted in on-path glances increasing in duration, while off-path glances decreased in number. Furthermore, the inhibited off-path glances were typically not compensated for later. That is, off-path glances were cancelled, not delayed. This was the case both in relation to the cognitive task (near-term) and the traffic environment (far-term). There was thus a general reduction in the number of glances towards situationally relevant off-path locations, but the timing of the remaining glances was unaffected. These findings provide a deeper understanding of the mechanism behind gaze concentration and can contribute to both understanding and prediction of safety relevant effects of cognitive load in car drivers.     

The impact of navigation system display size and environmental illumination on young driver mental workload

Driver distraction is a major cause of road crashes and has a great influence on road safety. In vehicles, one of the common distracting sources is navigation systems (NSs). The navigation system (NS) can distract the driver due to following directions and reading the provided information through its display. These tasks take the driver’s attention from the primary task of driving and may cause poor driving performance, increasing the risk of crashes. In this paper, the effect of the environment (i.e., urban areas and rural areas), the navigation system display (NSD) size, environmental illumination, and gender on young drivers between the ages of 18 and 29 years mental workload was investigated using a simulated driving experiment. To evaluate each driving condition, the NASA-TLX (NASA Task Load Index) workload assessment tool, and a distraction evaluation element, were introduced and used to assess the overall workload, the workload subscales and the distraction by the NSD. The assessment showed a higher perceived overall workload for urban areas and night driving as compared to a rural areas and daytime driving. Moreover, the results showed a greater perceived distraction by the NSD in urban areas compared to driving in rural areas. The subjects also felt distracted when using the small NS compared to using the large NS. The study concluded that urban areas driving, and night driving creates higher perceived workload than rural areas and daytime driving. Furthermore, small NSD leads to more perceived distraction than large NSD while driving. The NSD designers may utilize this research findings to optimize NSD designs to improve driving safety, performance and comfort. Moreover, this study contributes to our understanding of the effect of the NSD size on driving workload and distraction.     

Effects of speed display signs on driving speed at pedestrian crossings on collector streets

This study was designed to evaluate the short- and long-term effects of speed display signs on driving speed at pedestrian crossings in a low-speed (40 km/h) urban environment. Driving speeds were compared 1 week before installation, after installation (1 week; 1 month; 3 months; 5 months) and 1 week after removal. The main results showed that the speed displays decreased the mean speed by 0.5–2.9 km/h, which translates to a 4–22% drop in pedestrian fatality risk. Furthermore, there was a drop in the proportion of speeding vehicles and approaching speed of individual vehicles. The decrease in speed persisted over time, suggesting that speed displays may reduce speeds in the long term. In conclusion, installing speed displays at pedestrian crossings on collector streets reduces driving speeds and could contribute to the safety of pedestrians.