Commentary training improves responsiveness to hazards in a driving simulator

Can commentary driving produce safer drivers? Producing a verbal commentary of potential hazards during driving has long been considered by the police to improve hazard perception skills. In this study we investigated whether learner drivers would benefit from being trained to produce a commentary drive. All learners were initially assessed on a virtual route in a driving simulator that contained 9 hazards. One group of drivers was then trained in commentary driving, and their subsequent simulated driving behaviour was compared to a control group. The results showed that the trained group had fewer crashes, reduced their speed sooner on approach to hazards, and applied pressure to the brakes sooner than untrained drivers. Conversely the untrained drivers’ behaviour on approach to hazards was symptomatic of being surprised at the appearance of the hazards. The benefit of training was found to be greater for certain types of hazard than others.     

Hazard perception of motorcyclists and car drivers

The current study compares hazard perception (HP) performance of 50 male drivers with and without a motorcycle license in order to generalize results. A video-based HP test, measuring reaction times to traffic scenes, was administered to these two groups of drivers. Participants with a motorcycle license performed better than participants without a motorcycle license. ANOVA indicated that learning improved linearly for participants with a motorcycle license but not for participants without a motorcycle license. No evidence that HP was predicted by age was found. HP scores for drivers who reported previous involvement in an accident were lower than for those who reported not being involved in an accident. The results are discussed in the context of sensitivity and response bias models.     

Applying the motorcyclist's perspective to improve car drivers' attitudes towards motorcyclists

This study sought to provide a first crucial step in the direction of developing an intervention program aimed at improving safe attitudes and skills among car drivers towards motorcycles. We intended to improve drivers’ attitudes towards motorcyclists by exposing them to demands that motorcyclists face on the road. Car drivers were exposed to hazard perception clips taken from a motorcyclist's perspective, and interactive hazards in a motorcycle simulator. Car hazard perception clips and a car simulator were used as control conditions. A questionnaire assessed participant knowledge and attitudes towards motorcyclists before and after the intervention. After the intervention participants had more empathic- and fewer negative-attitudes, as well as safer attitudes towards motorcyclists. Self-reported attitude-change suggested that the use of motorcycle hazard perception clips was more effective than the simulator, and the intervention was most effective for those car drivers who reported the most negative attitudes prior viewing the clips or riding the simulator. Providing car drivers with a perspective of the motorcyclist may prove to be a useful tool for promoting safer attitudes towards motorcyclists.     

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.     

A comparison of the hazard perception ability of accident-involved and accident-free motorcycle riders

Hazard perception is the ability to read the road and is closely related to involvement in traffic accidents. It consists of both cognitive and behavioral components. Within the cognitive component, visual attention is an important function of driving whereas driving behavior, which represents the behavioral component, can affect the hazard perception of the driver. Motorcycle riders are the most vulnerable types of road user. The primary purpose of this study was to deepen our understanding of the correlation of different subtypes of visual attention and driving violation behaviors and their effect on hazard perception between accident-free and accident-involved motorcycle riders. Sixty-three accident-free and 46 accident-involved motorcycle riders undertook four neuropsychological tests of attention (Digit Vigilance Test, Color Trails Test-1, Color Trails Test-2, and Symbol Digit Modalities Test), filled out the Chinese Motorcycle Rider Driving Violation (CMRDV) Questionnaire, and viewed a road-user-based hazard situation with an eye-tracking system to record the response latencies to potentially dangerous traffic situations. The results showed that both the divided and selective attention of accident-involved motorcycle riders were significantly inferior to those of accident-free motorcycle riders, and that accident-involved riders exhibited significantly higher driving violation behaviors and took longer to identify hazardous situations compared to their accident-free counterparts. However, the results of the regression analysis showed that aggressive driving violation CMRDV score significantly predicted hazard perception and accident involvement of motorcycle riders. Given that all participants were mature and experienced motorcycle riders, the most plausible explanation for the differences between them is their driving style (influenced by an undesirable driving attitude), rather than skill deficits per se. The present study points to the importance of conceptualizing the influence of different driving behaviors so as to enrich our understanding of the role of human factors in road accidents and consequently develop effective countermeasures to prevent traffic accidents involving motorcycles.     

Traffic safety among motorcyclists in Norway: A study of subgroups and risk factors

Although it is widely recognized that motorcyclists have a particularly high accident risk, our knowledge of the mechanisms producing this accident risk is incomplete. The aims of the present paper are to identify subgroups of motorcyclists with a particularly high accident risk and to identify the relevant risk factors at work. The study presented in this paper relies both on a questionnaire (N = 3356) relating rider characteristics, behaviors and accident risk, and analyses of fatal motorcycle accidents (ca. 100) from 2005 to 2008 in Norway. The results reveal that riders of racing replica bikes (sport bikes), and riders younger than 19 years, including especially youths (16–17 years) riding light motorcycles (≤125 cm³), are subgroups of Norwegian motorcyclists with particularly high accident risks. Analysis of fatal motorcycle accidents reveals that about half of the fatal accidents involve sport bikes. Nearly all fatal accidents with sport bikes involved excessive speed. The combination of low age, low experience, risky behavior and “unsafe” attitudes seems to be a particular potent risk factor for Norwegian motorcyclists.     

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).     

Effects of valerian on subjective sedation,field sobriety testing and driving simulator performance

IntroductionThe availability of herbal medicines over-the-counter (OTC) has increased the use of natural products for self-treatment. Valerian has been used to effectively treat generalized anxiety disorder and insomnia. Studies suggest that valerenic acid may increase gamma-aminobutyric acid (GABA) modulation in the brain. Benzodiazepines have a similar mechanism of action and have been linked to an increased risk of hospitalizations due to traffic accidents. Despite the risk of somnolence, the safety of driving while under the influence of valerian remains unknown.PurposeThe purpose of the study was to determine the effects of a one-time valerian 1600 mg dose on subjective sedation effects, standardized field sobriety testing (SFST) and driving simulator performance parameters.MethodsThe study design was a randomized, placebo-controlled, double-blind, cross-over trial. For each session, participants received either a dose of valerian or placebo. The outcome measures included a simple visual reaction test (SVRT), subjective sleepiness scales, SFST performance scores, and driving simulator performance parameters.ResultsThere were no significant differences in the SVRT or sleepiness scales between placebo and valerian exposures, but the study may have been underpowered. SFST total and individual test failure rates were not significantly different between the two exposures. The driving simulator performance parameters were equivalent between the two exposure conditions.ConclusionsA one-time valerian 1600 mg dose, often used to treat insomnia, does not appear to impair driving simulator performance after acute ingestion.     

Route familiarity breeds inattention: A driving simulator study

Inattention is a major cause of traffic accidents. Here, we show that, contrary to common-sense expectation, familiarity with a route is itself a source of driving impairment. This effect may be attributed to increased mind-wandering along familiar routes. In the present work, participants followed a vehicle along a route with which they were either familiar or unfamiliar. During the experimental session, the lead-vehicle braked at random locations, forcing participants to brake to avoid a collision. Participants were also required to respond with a button press when they noticed pedestrians heading toward the road from a sidewalk. In Experiment 1 we found that familiar drivers follow the lead vehicle more closely and are slower to notice approaching pedestrians. In Experiment 2, with following distance held constant, reaction times to central and peripheral events were longer for familiar drivers. Consistent with the mind-wandering hypothesis, all these effects were eliminated in Experiment 3 when drivers were made to focus on the driving task.     

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 use of adaptation to reduce simulator sickness in driving assessment and research

The technical advancement of driving simulators has decreased their cost and increased both their accuracy and fidelity. This makes them a useful tool for examining driving behavior in risky or unique situations. With the approaching increase of older licensed drivers due to aging of the baby boomers, driving simulators will be important for conducting driving research and evaluations for older adults. With these simulator technologies, some people may experience significant effects of a unique form of motion sickness, known as simulator sickness. These effects may be more pronounced in older adults. The present study examined the feasibility of an intervention to attenuate symptoms of simulator sickness in drivers participating in a study of a driving evaluation protocol. Prior to beginning the experiment, the experimental groups did not differ in subjective simulator sickness scores as indicated by Revised Simulator Sickness Questionnaire scores (all p > 0.5). Participants who experienced a two-day delay between an initial acclimation to the driving simulator and the driving session experienced fewer simulator sickness symptoms as indicated by RSSQ total severity scores than participants who did not receive a two-day delay (F(1,88) = 4.54, p = .036, partial η² = .049). These findings have implications for improving client well-being and potentially increasing acceptance of driving simulation for driving evaluations and for driving safety research.     

The acute effects of 3,4-methylenedioxymethamphetamine and methamphetamine on driving: A simulator study

Objectives

Illicit drugs such as MDMA and methamphetamine are commonly abused drugs that have also been observed to be prevalent in drivers injured in road accidents. Their exact effect on driving and driving behavior has yet to be thoroughly investigated.

Methods

Sixty-one abstinent recreational users of illicit drugs comprised the participant sample, with 33 females and 28 males, mean age 25.45 years. The three testing sessions involved oral consumption of 100 mg MDMA, 0.42 mg/kg methamphetamine, or a matching placebo. The drug administration was counter-balanced, double-blind, and medically supervised. At each session driving performance was assessed 3 h and 24 h post drug administration on a computerized driving simulator.

Results

At peak concentration overall impairment scores for driving (F_2,118 = 9.042, p < 0.001) and signaling (F_2,118 = 4.060, p = 0.020) were significantly different for the daytime simulations. Performance in the MDMA condition was worse than both the methamphetamine (p = 0.023) and placebo (p < 0.001) conditions and the methamphetamine condition was also observed to be worse in comparison to the placebo (p = 0.055). For signaling adherence, poorer signaling adherence occurred in both the methamphetamine (p = 0.006) and MDMA (p = 0.017) conditions in comparison to placebo in the daytime simulations.

Conclusions

The findings of this study have for the first time illustrated how both MDMA and methamphetamine effect driving performance, and provide support for legislation regarding testing for the presence of illicit drugs in impaired or injured drivers as deterrents for driving under the influence of illicit drugs.     

Motorcyclist's lane position as a factor in right-of-way violation collisions: A driving simulator study

A driver turning left and failing to notice an oncoming motorcyclist until too late is the most common cause of motorcycle collisions. Consequently, much previous research has focused on motorcycle properties, such as size, shape, and color to explain its inconspicuousness. However, collision statistics remain largely unchanged, suggesting that the issue may not be related solely to the motorcycle's static properties. In the present study, we examined a different characteristic of the motorcycle, namely its trajectory of approach. Seventeen participants faced oncoming traffic in a high-fidelity driving simulator and indicated when gaps were safe enough for them to turn left at an intersection. We manipulated the size of the gaps and the type of oncoming vehicle over 135 trials, with gap sizes varying from 3 to 5 s, and vehicles consisting of either a car, a motorcycle in the left-of-lane position, or a motorcycle in the right-of-lane position. Our results show that drivers are more likely to turn in front of an oncoming motorcycle when it travels in the left-of-lane position than when it travels in the right-of-lane position.     

Some hazards are more attractive than others: Drivers of varying experience respond differently to different types of hazard

The ability to detect hazards in video clips of driving has been inconsistently linked to driving experience and skill. One potential reason for the lack of consistency is the failure to understand the structural differences between those hazards that discriminate between safe and unsafe drivers, and those that do not. The current study used a car simulator to test drivers of differing levels of experience on approach to a series of hazards that were categorized a priori according to their underlying structure. The results showed that learner drivers took longer to fixate hazards, although they were particularly likely to miss hazards that were obscured by the environment (such as a pedestrian emerging from behind a parked truck). While drivers with a moderate amount of experience were as fast as driving instructors to look at hazards, they spent the greatest amount of time looking at them. Only instructors’ ability to detect hazards early in the approach translated into differences in driving speed for certain types of hazard. The results demonstrate that drivers of varying experience respond differently to different hazards, and lay the foundations for a hazard typology.     

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.     

The alerting effect of hitting a rumble strip—A simulator study with sleepy drivers

A moving base driving simulator experiment was carried out in order to investigate the effects of milled rumble strips on driver fatigue. There were rumble strips both at the edge line and centre line. Four different physical designs of milled rumble strips (yielding noise values from 1.5 to 16 dBA) and two placements on shoulder were used in the experiment. Sound and vibrations from real milled rumble strips were reproduced in the simulator. In total 35 regular shift workers drove during the morning hours after a full night shift. The main results showed an increase in sleepiness indicators (EEG alpha/theta activity, eye closure duration, standard deviation of lateral position, subjective sleepiness) from start to before hitting the rumble strip, an alerting effect in most parameters (not subjective sleepiness) after hitting the strip. The alertness enhancing effect was, however, short and the sleepiness signs returned 5 min after the rumble strip hit. Essentially no effects were seen due to type of strip. It was concluded that various aspects of sleepiness are increased before hitting a rumble strip and that the effect is very short-lived. Type of strip, as used in the present study did not have any effect.     

Sleepiness and prediction of driver impairment in simulator studies using a Cox proportional hazard approach

Cox proportional hazard models were used to study relationships between the event that a driver is leaving the lane caused by sleepiness and different indicators of sleepiness. In order to elucidate different indicators’ performance, five different models developed by Cox proportional hazard on a data set from a simulator study were used. The models consisted of physiological indicators and indicators from driving data both as stand alone and in combination. The different models were compared on two different data sets by means of sensitivity and specificity and the models’ ability to predict lane departure was studied. In conclusion, a combination of blink indicators based on the ratio between blink amplitude and peak closing velocity of eyelid (A/PCV) (or blink amplitude and peak opening velocity of eyelid (A/POV)), standard deviation of lateral position and standard deviation of lateral acceleration relative road (ddy) was the most sensitive approach with sensitivity 0.80. This is also supported by the fact that driving data only shows the impairment of driving performance while blink data have a closer relation to sleepiness. Thus, an effective sleepiness warning system may be based on a combination of lane variability measures and variables related to eye movements (particularly slow eye closure) in order to have both high sensitivity (many correct warnings) and acceptable specificity (few false alarms).     

Capturing the serial nature of older drivers’ responses towards challenging events: A simulator study

Older drivers’ ability to trigger simultaneous responses in reaction to simulated challenging road events was examined through crash risk and local analyses of acceleration and direction data provided by the simulator. This was achieved by segregating and averaging the simulator's primary measures according to six short time intervals, one before and five during the challenging events. Twenty healthy adults aged 25-45 years old (M = 29.5 ± 4.32) and 20 healthy adults aged 65 and older (M = 73.4 ± 5.17) were exposed to five simulated scenarios involving sudden, complex and unexpected maneuvres. Participants were also administered the Useful Field of View (UFOV), single reaction time and choice reaction time tests, a visual secondary task in the simulator, and a subjective workload evaluation (NASA-TLX). Results indicated that the challenging event that required multiple synchronized reactions led to a higher crash rate in older drivers. Acceleration and orientation data analyses confirmed that the drivers who crashed limited their reaction. The other challenging events did not generate crashes because they could be anticipated and one response (braking) was sufficient to avoid crash. Our findings support the proposal (Hakamies-Blomqvist, L., Mynttinen, S., Backman, M., Mikkonen, V., 1999. Age-related differences in driving: are older drivers more serial? International Journal of Behavioral Development 23, 575-589) that older drivers have more difficulty activating car controls simultaneously putting them at risk when facing challenging and time pressure road events.     

The effect of three low-cost engineering treatments on driver fatigue: A driving simulator study

Three engineering treatments were implemented in a driving simulator study to assess the effect of road-based measures on alleviating the symptoms of fatigue. Using results from previous research on the effect of circadian rhythms on fatigue-related crashes, two groups of male drivers were recruited for this study: young shift workers under the age of 35, who attended immediately after their night shift, and older drivers over the age of 45, who completed the study during the ‘post lunch dip’ period, after consuming lunch. Eye tracking (PERCLOS) and lateral driver performance measures were used to assess whether baseline measures of fatigue changed after drivers experienced each of the three treatments, which included variable message signs, chevrons and rumble strips. Results showed a marked difference in these measures between drivers’ baseline (not fatigued) and experimental (fatigued) visits. There were also some reductions in lateral deviation and eye closure (as measured by PERCLOS) when the treatments were encountered, but no marked difference between the three treatments. These results suggest that in addition to driver- and vehicle-based methods currently employed to mitigate the effects of fatigue, the inclusion of such engineering measures may help alleviate fatigue-related impairments in driving, particularly if such treatments are implemented during long stretches of straight monotonous roads which are known to be associated with fatigue-related crashes. However, positive effects of the treatments were short lived, prompting the need for further investigations on their optimal frequency of presentation and combination to achieve maximum impact from these low-cost, road-based treatments.     

The effect of different delineator post configurations on driver speed in night-time traffic: A driving simulator study

The aim of the study was to investigate how different delineator post configurations affect driver speed in night-time traffic. In addition, the potential speed effect of introducing a secondary task was investigated. The study was carried out in a car simulator on a road stretch including straight road sections as well as curves with different radii. Fourteen drivers participated in the study and the results show that absence of delineator posts leads to reduced speed. However, provided that there are delineator posts continuously present along the road, the overall driver speed is basically the same, regardless of the spacing between the delineator posts. The results also imply that to reduce driver speed in curves with small radius, using more compact spacing of posts in these curves as compared to in curves with a larger radius, could be a potential strategy. Additionally, the speed reducing effect of a secondary task was only prevailing where the task was initiated.