A simulator study of the effects of singing on driving performance

This study aimed to investigate how singing while driving affects driver performance. Twenty-one participants completed three trials of a simulated drive concurrently while performing a peripheral detection task (PDT); each trial was conducted either without music, with participants listening to music, or with participants singing along to music. It was hypothesised that driving performance and PDT response times would be impaired, and that driver subjective workload ratings would be higher, when participants were singing to music compared to when there was no music or when participants were listening to music. As expected, singing while driving was rated as more mentally demanding, and resulted in slower and more variable speeds, than driving without music. Listening to music was associated with the slowest speeds overall, and fewer lane excursions than the no music condition. Interestingly, both music conditions were associated with slower speed-adjusted PDT response times and significantly less deviation within the lane than was driving without music. Collectively, results suggest that singing while driving alters driving performance and impairs hazard perception while at the same time increasing subjective mental workload. However, singing while driving does not appear to affect driving performance more than simply listening to music. Further, drivers’ efforts to compensate for the increased mental workload associated with singing and listening to music by slowing down appear to be insufficient, as evidenced by relative increases in PDT response times in these two conditions compared to baseline.     

Monitoring drivers’ mental workload in driving simulators using physiological measures

Many traffic accidents are caused by, or at least related to, inadequate mental workload, when it is either too low (vigilance) or too high (stress). Creating variations in mental workload and accident-prone driving for research purposes is difficult in the real world. In driving simulators the measurement of driver mental workload is relatively easily conducted by means of physiological measures, although good research skills are required and it is time-consuming. The fact that modern driving simulator environments are laboratory-equivalent nowadays allows full control with respect to environmental conditions, scenarios and stimuli, and enables physiological measurement of parameters of mental workload such as heart rate and brain activity. Several examples are presented to illustrate the potential of modern high-standard driving simulator environments regarding the monitoring of drivers’ mental workload during task performance.     

The effects of texting on driving performance in a driving simulator: The influence of driver age

Distracted driving is a significant contributor to motor vehicle accidents and fatalities, and texting is a particularly significant form of driver distraction that continues to be on the rise. The present study examined the influence of driver age (18–59 years old) and other factors on the disruptive effects of texting on simulated driving behavior. While ‘driving’ the simulator, subjects were engaged in a series of brief text conversations with a member of the research team. The primary dependent variable was the occurrence of Lane Excursions (defined as any time the center of the vehicle moved outside the directed driving lane, e.g., into the lane for oncoming traffic or onto the shoulder of the road), measured as (1) the percent of subjects that exhibited Lane Excursions, (2) the number of Lane Excursions occurring and (3) the percent of the texting time in Lane Excursions. Multiple Regression analyses were used to assess the influence of several factors on driving performance while texting, including text task duration, texting skill level (subject-reported), texting history (#texts/week), driver gender and driver age. Lane Excursions were not observed in the absence of texting, but 66% of subjects overall exhibited Lane Excursions while texting. Multiple Regression analysis for all subjects (N = 50) revealed that text task duration was significantly correlated with the number of Lane Excursions, and texting skill level and driver age were significantly correlated with the percent of subjects exhibiting Lane Excursions. Driver gender was not significantly correlated with Lane Excursions during texting. Multiple Regression analysis of only highly skilled texters (N = 27) revealed that driver age was significantly correlated with the number of Lane Excursions, the percent of subjects exhibiting Lane Excursions and the percent of texting time in Lane Excursions. In contrast, Multiple Regression analysis of those drivers who self-identified as not highly skilled texters (N = 23) revealed that text task duration was significantly correlated with the number of Lane Excursions. The present studies confirm past reports that texting impairs driving simulator performance. Moreover, the present study demonstrates that for highly skilled texters, the effects of texting on driving are actually worse for older drivers. Given the increasing frequency of texting while driving within virtually all age groups, these data suggest that ‘no texting while driving’ education and public service messages need to be continued, and they should be expanded to target older drivers as well.     

Self-rated driving performance among elderly drivers referred for driving evaluation

PURPOSE: To explore whether elderly drivers of varying driving skill levels (1) differ in their perception of their driving evaluation performance and (2) determine if self-rated driving evaluation performance is related to cognitive ability. METHODS: One hundred and fifty-two drivers aged 65 years or older and referred for a driving evaluation were enrolled into the study. Subjects were asked the question, "how well do you think you will perform today on your driving evaluation compared to others your own age?" Subjects also completed the Mini-Mental State Exam and a 30-min drive on a STISIM Drivetrade mark simulation (Systems Technology, Inc., Hawthorne, CA). Only 47 subjects completed both the simulated drive and self-rated item. RESULTS: Sixty-five percent of drivers rated themselves as performing better on a driving test than others of their age. Another 31.9% felt they would perform the same as others of their age on a driving test. A 50.0% of those considering themselves "a little better" and 52.9% of those considering themselves "a lot better" had an unsafe driving performance. As self-rated driving evaluation performance increased, there was a significantly increased risk of unsafe driving (p=0.02) in the study population. Drivers who considered themselves at least a little better than others of their age were over four times more likely to be unsafe drivers compared to others who believed they were comparable to or worse than other drivers of their age (RR=4.13, 95% CI=1.08-15.78). There was no significant difference in MMSE between self-rating groups (p=0.76). CONCLUSION: Older drivers assign high ratings to their driving performance, even in the presence of suspected skill decline. Cognitive ability was not related to self-rated driving evaluation performance.     

The relationship between cognitive performance,perceptions of driving comfort and abilities,and self-reported driving restrictions among healthy older drivers

The objective of the present study was to examine the relationship between cognitive performance, driver perceptions and self-reported driving restrictions. A cross-sectional analysis was conducted on baseline data from Candrive II, a five-year prospective cohort study of 928 older drivers aged 70–94 years from seven cities. Cognitive performance was assessed using the Montreal Cognitive Assessment (MoCA) as well as the Trail Making Test, parts A and B. Driver perceptions were assessed using the Day and Night Driving Comfort Scales and the Perceived Driving Abilities scale, while driving practices were captured by the Situational Driving Frequency and Avoidance scales, as well as the Driving Habits and Intentions Questionnaire. The baseline data indicates this cohort is largely a cognitively intact group. Univariate regression analysis showed that longer Trails A and B completion times were significantly, but only modestly associated with reduced driving frequency and perceived driving abilities and comfort, as well as a significant tendency to avoid more difficult driving situations (all p < .05). Most of these associations persisted after adjusting for age and sex, as well as indicators of health, vision, mood and physical functioning. Exceptions were Trails A and B completion times and situational driving frequency, as well as time to complete Trails B and current driving restrictions. After adjusting for the confounding factors, the total MoCA score was not associated with any of the driving measure scores while the number of errors on Trails A was significantly associated only with situational driving frequency and number of errors on Trails B was significantly associated only with situational driving avoidance. Prospective follow-up will permit examination of whether baseline cognition or changes in cognition are associated with changes in driver perceptions, actual driving restrictions and on-road driving outcomes (e.g., crashes, violations) over time.     

Age and inconsistency in driving performance

Research in cognitive neuropsychology suggests that investigation of the within-person variability, or inconsistency, of cognitive performance may provide valuable insights into ageing mental processes. It is rare though, for this interest in intraindividual variability to extend to everyday activities. As this may provide important information about driving behaviour, we therefore assessed age differences in driving inconsistency in younger (n = 24, M age = 21.29 years) and older (n = 21, M age = 71.24 years) persons who drove in residential, urban and motorway conditions in a fully immersive driving simulator. In measures of headway (maintaining a safe distance to a preceding vehicle) and lateral lane position, older drivers exhibited significantly greater performance inconsistency, and this was particularly marked in the faster motorway condition. Older drivers also recorded greater perceived mental demands associated with driving, and greater within-person variability across a range of cognitive measures. The findings suggest that age-related deficits in attentional and executive control may affect the consistency of driving performance in older persons. Discussion considers interventions to introduce in-vehicle systems to help maintain attention in older drivers, and to intervene when safety-critical boundaries are exceeded.     

Age differences in simulated driving performance: Compensatory processes

In the context of driving, the reported experiment examines compensatory processes for age-related declines in cognitive ability. Younger (26–40 years) and older (60+ years) participants (n = 22 each group) performed a car following task in a driving simulator. Several performance measures were recorded, including assessments of anticipation of unfolding traffic events. Participants also completed a range of measures of cognitive ability – including both fluid and crystallised abilities. Three examples of age-related compensation are reported: (i) older drivers adopted longer headways than younger drivers. Data were consistent with this being compensation for an age-related deficit in complex reaction time; (ii) older drivers with relatively higher cognitive ability anticipated traffic events more frequently, whereas the reverse pattern was found for younger drivers; and, (iii) older drivers with greater crystallised ability were less reliant on spatial ability to maintain lane position. Consistent with theories of ‘cognitive reserve’, interactions between crystallised ability and age for self-report workload suggested that compensation for age-related cognitive ability deficits required investment of additional effort. Results are considered in the context of the prospects of further assessment of older drivers.     

A driving simulator study of driver performance on deceleration lanes

Deceleration lanes are important because they help drivers transition from high-speed lanes to low-speed ramps. Although they are designed to allow vehicles to depart the freeway safely and efficiently, many studies report high accident rates on exit ramps with the highest percentage of crashes taking place in deceleration lanes.     

The effects of driver training on simulated driving performance

Given that the beneficial effects of driver training on accident risk may not be an appropriate criterion measure, this study investigates whether professionally trained and experienced drivers exhibit safer driving behaviour in a simulated driving task compared with drivers without professional driver training. A sample of 54 police trained drivers and a sample of 56 non-police trained drivers were required to complete two tasks. Firstly to overtake a slow-moving bus on a hazardous stretch of single-lane road with bends and hills and secondly to follow a lead vehicle travelling at 55mph in a built-up section with a speed limit of 30mph. Results showed that in comparison with non-police trained drivers, police drivers were significantly less likely to cross the central division of the road at unsafe locations during the overtaking task and reduced their speed on approach to pedestrians at the roadside in the following task to a greater extent. Police drivers also adopted a more central lane position compared with non-police trained drivers on urban roads and at traffic lights during the following task. Driver group differences in simulated driving performance are discussed with reference to the implications for driver training assessment and skill development.     

Modeling the influence of Chevron alignment sign on young male driver performance: A driving simulator study

In China, the Chevron alignment sign on highways is a vertical rectangle with a white arrow and border on a blue background, which differs from its counterpart in other countries. Moreover, little research has been devoted to the effectiveness of China’s Chevron signs; there is still no practical method to quantitatively describe the impact of Chevron signs on driver performance in roadway curves. In this paper, a driving simulator experiment collected data on the driving performance of 30 young male drivers as they navigated on 29 different horizontal curves under different conditions (presence of Chevron signs, curve radius and curve direction). To address the heterogeneity issue in the data, three models were estimated and tested: a pooled data linear regression model, a fixed effects model, and a random effects model. According to the Hausman Test and Akaike Information Criterion (AIC), the random effects model offers the best fit. The current study explores the relationship between driver performance (i.e., vehicle speed and lane position) and horizontal curves with respect to the horizontal curvature, presence of Chevron signs, and curve direction. This study lays a foundation for developing procedures and guidelines that would allow more uniform and efficient deployment of Chevron signs on China’s highways.     

Effect of different breath alcohol concentrations on driving performance in horizontal curves

Driving under the influence of alcohol on curved roadway segments has a higher risk than driving on straight segments. To explore the effect of different breath alcohol concentration (BrAC) levels on driving performance in roadway curves, a driving simulation experiment was designed to collect 25 participants’ driving performance parameters (i.e., speed and lane position) under the influence of 4 BrAC levels (0.00%, 0.03%, 0.06% and 0.09%) on 6 types of roadway curves (3 radii × 2 turning directions). Driving performance data for 22 participants were collected successfully. Then the average and standard deviation of the two parameters were analyzed, considering the entire curve and different sections of the curve, respectively.     

The impact of mental health symptoms on heavy goods vehicle drivers’ performance

High levels of psychological distress in fulltime employees are prevalent (4.5% per month). Symptoms of impaired mental health include difficulties with attention, concentration, motivation, decision-making, visuo-motor control, and psychomotor reaction times. There is limited research on the impact these symptoms have on heavy goods vehicle (HGV) drivers’ performance. In this study 1324 HGV drivers were surveyed using the Depression, Anxiety, Stress Scale (DASS) and the Health and Performance at Work Questionnaire (HPQ). Depression, anxiety and stress had little effect on driver absenteeism rates or self-rated driving performance. However, severe (1.5% of drivers) and very severe (1.8% of drivers) depression was associated with an increased odds ratio (OR = 4.5 and 5.0, respectively) for being involved in an accident or near miss in the past 28 days. This odd ratio is akin to driving with a blood alcohol content of about 0.08%. Given the number of HGV vehicles and the prevalence of depression this equates to 10,950 HGV drivers with an increased statistical risk of an accident or near miss. As the impact of HGV accidents is potentially large, including loss of life, it would be sensible to extend the research findings here into an action plan.     

The effect of age,gender and attitudes on self-regulation in driving

Self-regulation in driving has primarily been studied as a precursor to driving cessation in older people, who minimise driving risk and compensate for physical and cognitive decline by avoiding driving in challenging circumstances, e.g. poor weather conditions, in the dark and at busy times. This research explores whether other demographic groups of drivers adopt self-regulatory behaviours and examines the effects of affective and instrumental attitudes on self-regulation across the lifespan. Quantitative data were collected from 395 drivers. Women were significantly more likely than men to engage in self-regulation, and to be negatively influenced by their emotions (affective attitude). A quadratic effect of age on self-regulation was determined such that younger and older drivers reported higher scores for self-regulation than middle-years’ drivers. However, this effect was affected by experience such that when experience was controlled for, self-regulation increased with age. Nevertheless, anxious driving style and negative affective attitude were independent predictors of self-regulation behaviours. Results suggest that self-regulation behaviours are present across the driving lifespan and may occur as a result of driving anxiety or low confidence rather than as an effect of ageing.     

The deterioration of driving performance over time in drivers with untreated sleep apnea

Sleep apnea increases risk of driving crashes when left untreated. This study examined the driving performance decrements of untreated, undiagnosed sleep apnea drivers compared with healthy controls in a monotonous highway driving simulator task. It was hypothesized that the sleep apnea group would perform worse during a driving simulator test compared with the control group. A significant group by time interaction occurred indicating that sleep apnea participants’ performance degraded more quickly over the course of the drive. In contrast with previous studies, this sleep apnea group did not include sleep disorder center patients, but rather community volunteers whose screening indicated a significant apnea/hypopnea index of 15 or greater. There may be inherent differences between patients and nonpatients with sleep apnea, as patients may have a more significant impact on their quality of life, causing them to seek treatment. Still, the results are clear that although the sleep apnea group drove similarly to the control group at the start of the drive, they are sensitive to time on task effects. These results support the need to diagnose and treat sleep apnea.     

Effects of THC on driving performance, physiological state and subjective feelings relative to alcohol

BACKGROUND: The effects of marijuana or THC on driving has been tested in several studies, but usually not in conjunction with physiological and subjective responses and not in comparison to alcohol effects on all three types of measures. OBJECTIVE: To assess the effects of two dosages of THC relative to alcohol on driving performance, physiological strain, and subjective feelings. METHOD: We tested the subjective feelings and driving abilities after placebo, smoking two dosages of THC (13 mg and 17 mg), drinking (0.05% BAC) and 24 h after smoking the high dose THC cigarette, while monitoring physiological activity of the drugs by heart rate. Fourteen healthy students, all recreational marijuana users, participated in the study. RESULTS: Both levels of THC cigarettes significantly affected the subjects in a dose-dependent manner. The moderate dose of alcohol and the low THC dose were equally detrimental to some of the driving abilities, with some differences between the two drugs. THC primarily caused elevation in physical effort and physical discomfort during the drive while alcohol tended to affect sleepiness level. After THC administration, subjects drove significantly slower than in the control condition, while after alcohol ingestion, subjects drove significantly faster than in the control condition. No THC effects were observed after 24 h on any of the measures.     

Self-regulation of driving and its relationship to driving ability among older adults

Although it is known that older drivers limit their driving, it is not known whether this self-regulation is related to actual driving ability. A sample of 104 older drivers, aged between 60 and 92, completed a questionnaire about driving habits and attitudes. Ninety of these drivers also completed a structured on-road driving test. A measure of self-regulation was derived from drivers' self-reported avoidance of difficult driving situations. The on-road driving test involved a standard assessment used to determine fitness to drive. Driving test scores for the study were based on the number of errors committed in the driving tests, with weightings given according to the seriousness of the errors. The most commonly avoided difficult driving situations, according to responses on the questionnaire, were parallel parking and driving at night in the rain, while the least avoided situation was driving alone. Poorer performance on the driving test was not related to overall avoidance of difficult driving situations. Stronger relationships were found between driving ability and avoidance of specific difficult driving situations. These specific driving situations were the ones in which the drivers had low confidence and that the drivers were most able to avoid if they wished to.     

Development and evaluation of a Driving Observation Schedule (DOS) to study everyday driving performance of older drivers

This paper describes the development and evaluation of an on-road procedure, the Driving Observation Schedule (DOS), for monitoring individual driving behavior. DOS was developed for use in the Candrive/Ozcandrive five-year prospective study of older drivers. Key features included observations in drivers’ own vehicles, in familiar environments chosen by the driver, with start/end points at their own homes. Participants were 33 drivers aged 75+ years, who drove their selected route with observations recorded during intersection negotiation, lane-changing, merging, low speed maneuvers and maneuver-free driving. Driving behaviors were scored by a specialist occupational therapy driving assessor and another trained observer. Drivers also completed a post-drive survey about the acceptability of DOS. Vehicle position, speed, distance and specific roadways traveled were recorded by an in-vehicle device installed in the participant's vehicle; this device was also used to monitor participants’ driving over several months, allowing comparison of DOS trips with their everyday driving. Inter-rater reliability and DOS feasibility, acceptability and ecological validity are reported here. On average, drivers completed the DOS trip in 30.48 min (SD = 7.99). Inter-rater reliability measures indicated strong agreement between the trained and the expert observers: intra-class correlations (ICC) = 0.905, CI 95% 0.747–0.965, p < 0.0001; Pearson product correlation, r (18) = .83, p < 0.05. Standard error of the measurement (SEM), method error (ME) and coefficient of variation (CV) measures were consistently small (3.0, 2.9 & 3.3%, respectively). Most participants reported being ‘completely at ease’ (82%) with the driving task and ‘highly familiar with the route’ (97%). Vehicle data showed that DOS trips were similar to participants’ everyday driving trips in roads used, roadway speed limits, drivers’ average speed and speed limit compliance. In summary, preliminary findings suggest that DOS can be scored reliably, is of feasible duration, is acceptable to drivers and representative of everyday driving. Pending further research with a larger sample and other observers, DOS holds promise as a means of quantifying and monitoring changes in older drivers’ performance in environments typical of their everyday driving.     

Hostility,driving anger,and dangerous driving: The emerging role of hemispheric preference

Background

Various studies have implicated psychosocial variables (e.g., hostility) in risk of dangerous driving and traffic accidents. However, whether these variables are related to more basic neurobiological factors, and whether such associations have implications for the modification of psychosocial risk factors in the context of driving, have not been examined in depth. This study examined the relationship between hemispheric preference (HP), hostility and self-reported dangerous driving, and the ability to affect driving anger via hemisphere activating cognitive exercises (HACE).

Methods

In Study 1, 254 Turkish students completed questionnaires of hostility, HP and driving behavior. In Study 2, we conducted a “proof of concept” experimental study, and tested effects of left, right and neutral HACE on driving anger, by exposing N = 650 Turkish students to written scenarios including either logical (left hemisphere), visuo-spatial (right hemisphere) or “mild doses” of both types of contents (control).

Results

In Study 1, left-HP was associated with higher hostility and with more dangerous driving, and hostility mediated the relationship between L-HP and reported driving behavior. In Study 2, only right-HACE led to immediate significant reductions in self-reported driving anger.

Conclusions

Left-HP is related to hostility and to dangerous driving, and it may be possible to partly reduce driving anger by right-HACE. Future studies must replicate these findings with objective measures, more enduring interventions and longer follow-ups.     

The influence of cruise control and adaptive cruise control on driving behaviour--a driving simulator study

Although Cruise Control (CC) is available for most cars, no studies have been found which examine how this automation system influences driving behaviour. However, a relatively large number of studies have examined Adaptive Cruise Control (ACC) which compared to CC includes also a distance control. Besides positive effects with regard to a better compliance to speed limits, there are also indications of smaller distances to lead vehicles and slower responses in situations that require immediate braking. Similar effects can be expected for CC as this system takes over longitudinal control as well. To test this hypothesis, a simulator study was conducted at the German Aerospace Center (DLR). Twenty-two participants drove different routes (highway and motorway) under three different conditions (assisted by ACC, CC and manual driving without any system). Different driving scenarios were examined including a secondary task condition. On the one hand, both systems lead to lower maximum velocities and less speed limit violations. There was no indication that drivers shift more of their attention towards secondary tasks when driving with CC or ACC. However, there were delayed driver reactions in critical situations, e.g., in a narrow curve or a fog bank. These results give rise to some caution regarding the safety effects of these systems, especially if in the future their range of functionality (e.g., ACC Stop-and-Go) is further increased.     

Mental workload when driving in a simulator: Effects of age and driving complexity

Driving errors for older drivers may result from a higher momentary mental workload resulting from complex driving situations, such as intersections. The present study examined if the mental workload of young and older active drivers vary with the difficulty of the driving context. We adopted the probe reaction time (RT) technique to measure the workload while driving in a simulator. The technique provided clear instructions about the primary (driving) and secondary (RT) tasks. To avoid structural interference, the secondary task consisted of responding as rapidly as possible with a vocal response (“top”) to an auditory stimulus. Participants drove through a continuous 26.4-km scenario including rural and urban sections and probes (stimuli) were given in a baseline static condition and in three different driving contexts embedded into the overall driving scenario. Specifically, stimuli were given randomly when (a) driving on straight roads at a constant speed, (b) approaching intersections for which the driver had to stop the car, and (c) when overtaking a slower vehicle. Unless a driving error was made, drivers did not need any emergency responses. Reaction time was defined as the temporal interval between the auditory stimulus and the onset of the corresponding verbal response detected from the analog signal of a piezo-electric microphone fixed on a headset (ms accuracy). Baseline RTs were similar for both groups. Both groups showed longer RTs when driving and RTs increased as the complexity of the driving contexts increased (driving straights, intersections, overtaking maneuvers). Compared to younger drivers, however, older drivers showed longer RTs for all driving contexts and the most complex driving context (overtaking maneuvers) yielded a disproportionate increase. In conclusion, driving leads to a greater mental workload for the older drivers than for the younger drivers and this effect was exacerbated by the more complex driving context (overtaking maneuvers).