Safety implications of co-locating road signs: A driving simulator investigation

BackgroundAs road complexity increases the requirement for number of road signs also increases, although the amount of road side space does not. One practical strategy to address this is to present multiple road signs on the same gantry (sign co-location). However, there is very little research on the safety implications of this practice.Method36 participants (mean age = 42.25 years, SD = 13.99, 18 females) completed three driving simulator scenarios, each scenario had a different sign co-location condition: no co-location, dual co-location and triple co-location. Each scenario presented similar information using direction signs, variable message signs and variable speed limit signs, under. Each drive included standard motorway driving (100 km/h speed zone) in free flow traffic and one emergency event where a lead vehicle suddenly braked. The scenario order was counterbalanced and the emergency event vehicle varied.ResultsOverall, there was no impact of co-locating signs on general driving performance. No significant difference was observed between conditions for reaction time and minimum headway in response to the emergency event. Participants were able to correctly choose their destination whether the signs were co-located or not.DiscussionFor the particular configuration of signs tested there is no evidence that co-location negatively impacts driving performance. However, there may be some implications for travel speed and the manner in which the emergency event is responded to. Future work should confirm the findings on real roads. These findings provided support for sign co-location as a practical and safe option for displaying multiple road signs in a confined area.     

The psychosocial purpose of driving and its relationship with the risky driving behaviour of young novice drivers

BackgroundThe overrepresentation of young drivers in road crashes, injuries and fatalities around the world has resulted in a breadth of injury prevention efforts including education, enforcement, engineering, and exposure control. Despite multifaceted intervention, the young driver problem remains a challenge for injury prevention researchers, practitioners and policy-makers. The intractable nature of young driver crash risks suggests that a deeper understanding of their car use – that is, the purpose of their driving – is required to inform the design of more effective young driver countermeasures.AimsThis research examined the driving purpose reported by young drivers, including the relationship with self-reported risky driving behaviours including offences.MethodsYoung drivers with a Learner or Provisional licence participated in three online surveys (N1 = 656, 17–20 years; N2 = 1051, 17–20 years; N3 = 351, 17–21 years) as part of a larger state-wide project in Queensland, Australia.ResultsA driving purpose scale was developed (the PsychoSocial Purpose Driving Scale, PSPDS), revealing that young drivers drove for psychosocial reasons such as for a sense of freedom and to feel independent. Drivers who reported the greatest psychosocial purpose for driving were more likely to be male and to report more risky driving behaviours such as speeding. Drivers who deliberately avoided on-road police presence and reported a prior driving-related offence had significantly greater PSPDS scores, and higher reporting of psychosocial driving purposes was found over time as drivers transitioned from the supervised Learner licence phase to the independent Provisional (intermediate) licence phase.Discussion and conclusionsThe psychosocial needs met by driving suggest that effective intervention to prevent young driver injury requires further consideration of their driving purpose. Enforcement, education, and engineering efforts which consider the psychosocial purpose of the driving are likely to be more efficacious than those which presently do not. Road safety countermeasures could reduce the young driver’s exposure to risk through such mechanisms as encouraging the use of public transport.     

Diverging diamond interchanges: A driving simulator study

This study assessed driver performance while navigating a Diverging Diamond Interchange (DDI) compared to a standard intersection in a driving simulator. A total of 201 Western Australian (WA) drivers aged 18–80 years completed the simulator drive and questionnaire. Measures of driving simulator performance assessed included time spent out of lane, number of lane excursions, compliance to the speed limit, crashes and near misses. Other driving measures, which were recorded by the researcher, included driver errors/violations such as red-light violations, wrong way violations and navigation errors. Qualitative information was also obtained in a post exit interview with each participant regarding the difficulties they experienced when driving through the DDI. A repeated-measure analysis of variance (r-ANOVA) was undertaken to examine differences in intersection type (DDI versus standard intersection) and driving performance measures from the driving simulator. The only significant result was compliance to the speed limit (F (1, 656) = 160.11, p < 0.001) on the driving simulator. A higher proportion of red-light violations were observed by the researcher as participants navigated through the DDI, compared to the standard intersection. Qualitative comments from participants also highlighted the need for better signage and road markings. Recommendations when DDIs are implemented include community education on speed limit compliance, avoidance of red-light violations and design improvements regarding signage and road markings.     

Cognitive and psychomotor tests as predictors of on-road driving ability in older primary care patients

This study examined the accuracy with which different cognitive and psychomotor assessment tools were able to predict driving ability among older primary care patients. A cross-sectional study of 50 older drivers (with an average age of 73.1 ± 7.0 years) was conducted. Participants who had been referred by their physicians for psychological assessment following a fitness-to-drive examination underwent both an on-road driving test and a cognitive assessment protocol that included the Senior Drivers Battery (SDB) that is currently administered at the Mobility and Land Transports Institute (MLTI) in Portugal, the Useful Field of View (UFOV) test, the Stroke Drivers Screening Assessment (SDSA), Addenbrooke’s Cognitive Examination Revised (ACE-R), the Trail Making Test, the Key Search test, and the Wechsler Adult Intelligence Scale (WAIS-III) Vocabulary and Block Design tests. Logistic regression analysis revealed that the performances of the participants on the SDSA, ACE-R, UFOV and SDB were the best predictors of on-road driving. Specific measures of processing speed and divided attention, visuospatial abilities, executive functions, psychomotor speed and global cognitive functioning may be useful for predicting unsafe driving. The practical implications of these findings are discussed with a view to developing new assessment models for determining driving fitness in older adults.     

The effects of an interactive cognitive task (ICT) in suppressing fatigue symptoms in driving

BackgroundProlonged drive on inter-urban, monotonous roads has the potential of causing a decrease in the general level of arousal leading to a state of underload and fatigue. This study examines the effectiveness of an interactive cognitive task (ICT) in delaying fatigue symptoms induced by underload conditions. The ICT is an auditory-motor task which is based on the basic principles of a knowledge game known as “Trivia”.MethodTen participants took part in two experimental sessions of 140 min drive in a fixed-base simulator. In a within-subject counterbalanced design one session consisted of driving without ICT and the other included ICT operation. In the ICT session the game was activated after 60 min of driving.ResultsWhen activated, the ICT increased physiological indicators of arousal, increased subjective feelings of alertness, and improved driving performance. The physiological and driving performance measures revealed that the ICT activation had an immediate but localized influence on arousal. Post-drive questionnaires showed that in the ICT condition, the participants’ level of motivation increased and their feelings of sleepiness decreased.ConclusionsEngaging in cognitive tasks can counteract the effects of underload and increases driving safety as long as they are active. However, additional research is necessary to determine the effects of long term use.     

The role of edge lines in curve driving

In order to evaluate the role of edge lines in curve driving we examined steering behaviour in the face of unexpected gradual changes in road geometry. Experienced drivers (N = 13) operating a fixed-base driving simulator steered a car along a single-lane (3.80 m or 7.60 m wide) winding road. The experimental track consisted of eight 90° curves with radii of curvature varying between 75 m and 500 m, separated by 500-m long straight line segments. The model-based nature of the simulator was used to create unexpected online changes in road geometry, implemented through a gradual displacement of one or both edge lines while drivers steered around the delineated bend. Although they regulated their speed as a function of road curvature, drivers were found to consistently cut into and out of the curves. When the edge lines did not move, drivers stabilized their lane position during the 20°–70° curve segments, adopting a position closer to the interior edge line for the narrower lane width and smaller radii of curvature. Motion of the interior edge line, whether inward or outward, gave rise to systematic changes in lane position, while motion of the exterior edge line did not affect driving behaviour. Overall, the results point to a visuo-motor strategy of steering based on zeroing-out changes in the rate of change of angular bearing of the tangent point.     

An examination of the relationships between cannabis use,driving under the influence of cannabis and risk-taking on the road

IntroductionSome studies have suggested that regular cannabis users appear to exhibit a general reckless driving style that may contribute to an inflated estimate of collisions related to driving under the influence of cannabis (DUIC) among this group.ObjectiveThis study investigated whether patterns of cannabis use would predict levels of self-reported unsafe driving behaviours and levels of performance observed in a driving simulator.MethodThe study investigated 48 young cannabis users with respect to frequency of cannabis consumption, alcohol use, driving exposure, self-reported dangerous driving habits, impulsivity, sensation seeking and performance in a driving simulator.ResultsCannabis use was positively associated with DUIC, with sensation seeking and with self-reports of risky driving. An ANOVA confirmed a significant effect of levels of consumption of cannabis among participants on self-report risk-taking in driving. Moreover, the observed behaviours during the simulation tasks correlated with risky driving habits, and with the self-reported frequency of driving in the hour following smoking cannabis or immediately after drinking alcohol.ConclusionSince cannabis usage and DUIC appear to be related to an overall reckless style of driving, it is proposed that public safety policies should be more holistic, simultaneously targeting multiple on-road dangerous behaviours for intervention.     

Effects of distraction and experience on situation awareness and simulated driving

This study examined the impact of cell phone conversation on situation awareness and performance of novice and experienced drivers. Driving performance and situation awareness among novice drivers ages 14–16 (n = 25) and experienced drivers ages 21–52 (n = 26) were assessed using a driving simulator. Performance was measured by the number of driving infractions committed: speeding, collisions, pedestrians struck, stop signs missed, and centerline and road edge crossings. Situation awareness was assessed through a query method and through participants’ performance on a direction-following task. Cognitive distractions were induced through simulated hands-free cell phone conversations. The results indicated that novice drivers committed more driving infractions and were less situationally aware than their experienced counterparts. However, the two groups suffered similar decrements in performance during the cell phone condition. This study provides evidence of the detrimental effects of cell phone use for both novice and experienced drivers. These findings have implications for supporting driving legislation that limits the use of cell phones (including hands-free) in motor vehicles, regardless of the driver’s experience level.     

Dynamic traffic management on a familiar road: Failing to detect changes in variable speed limits

Variable speed limits (VSL) are used more commonly around the globe lately. Although on a macroscopic level positive effects of VSLs have been reported, the caveat is that the impact of VSLs is very sensitive to the level of driver compliance. Thus far it is unknown whether all individual drivers are actually able to notice when a speed limit changes into another speed limit; a prerequisite for purposeful speed limit compliance in the first place. To simulate regular driving conditions, twenty-four participants were familiarised with a particular route by driving the same route in a driving simulator nineteen times on five separate days. Part of the route consisted of a motorway where VSL signs were regularly displayed above every driving lane. At drive nineteen, speed limits changed from 80 km/h to 100 km/h on four out of eight consecutive signs. After passing all signs, one expects 6.25% of the participants still to be unaware that the speed limit had increased (based on chance), while the results showed most participants had failed to notice the speed limit change (58.3%). Instead, they saw what they expected to see: a speed limit of 80 km/h. If the speed change had been vice versa, in other words from 100 km/h to 80 km/h, this would immediately result in speed offences, though not deliberately at all.     

Emotional intelligence and risky driving behaviour in adults

BackgroundRisky driving is considered a key predictive factor in road traffic accidents resulting in morbidity and mortality. Intra-individual emotional and personality factors have been shown to influence risk-taking behaviours among drivers. Despite this, there is limited research investigating the individual dimensions of these constructs and their relationship to risky driving behaviour (RDB). The current study therefore aimed to assess whether the individual dimensions of Emotional Intelligence (EI) were implicated in RDB.MethodsThe sample comprised 179 adults (55% male) aged between 18 and 64 years (M = 29.85, SD = 11.46) and who currently held a valid driver’s licence completed an online survey. Emotional Intelligence was assessed via self-report using the Swinburne University Emotional Intelligence Test (SUEIT), and RDB was measured using both the Brief Distracted Driving Scale (BDDS) and the Dula Dangerous Driving Index (DDDI).ResultsRegression analyses revealed that ‘Risky Driving’ was related to greater levels of Emotional Recognition and Expression and lesser Age [F_{(6, 172)} = 2.27, p < 0.05: R² = 7.3%], and the Negative Emotions sub-scale of DDDI, was significantly predicted by Emotional Control and Age [F_{(6, 172)} = 6.41, p < 0.05: R² = 18.3%]. A mediation model incorporating Age, Emotional Control scores and the Negative Emotions driving behaviour score indicated that a significant indirect effect of Age through Emotional Control (K² = 0.08, 95% CI [−0.02, −0.03]). (H [3] = 10.98, p = 0.012).ConclusionsLower scores on specific indices of EI are associated with increased rates of RDB, suggesting that poor emotional control may impede an individuals’ ability to make safe behavioural decisions when driving. The effect sizes for these models were small, however, and further research is needed to explore the contributory components in this association. Greater awareness of the role of emotional regulation and driving behaviours may be useful in preventing RDB in adults.     

Situational (state) anger and driving

Aggression and anger have been related to crash involvement, but the direct causal relation between situational anger and driving choices and abilities has not been examined empirically. In this study, 15 licensed drivers drove twice in a driving simulator, each time following one of two emotion inductions based on event recall: angry and neutral. Following anger induction, the drivers crossed more yellow traffic lights (p < .01) and tended to drive faster (non-significant). However, performance on emergency manoeuvres were unaffected by anger. In conclusion, it appears that state anger affects driving behaviour by increasing risk taking, without necessarily compromising the skilled driving behaviour, at least as far as these behaviours were evaluated in emergency situations in simulated driving.     

Using an Advance Time Meter display as means to reduce driving speed

ObjectiveTesting an experimental means to reduce motivation to drive fast.BackgroundOne determinant of that motivation may be a wrong presumption, demonstrated here: Time to reach destination declines about linearly to increase in driving speed. Actually, that time is a linear function of advance time, the inverse of speed. It is hypothesized that the behavioral by-product of the popularity of that fallacy could be counteracted by introducing an essential change to the speed-based continuous feedback provided to the driver – from a speedometer displaying instantaneous velocity to a gauge reporting advance time (denoted ATM), so that both average driving speed and speed variance are reduced.MethodIn two driving simulator experiments, driving speed of participants presented with either of the two types of gauge was recorded.ResultsThe main finding is that driving with feedback provided by an ATM gauge following prior briefing led to a significant reduction – ∼11 km/h – in mean speed, as well as to a significant reduction in between-driver speed variability, as compared with driving with an ordinary speedometer. It was also found that no significant difference was observed in the speeding behavior of participants driving with an ATM display for three ∼2-h sessions administered in three different days, so that the last session took place within seven days from the first one.ConclusionThe ATM gauge serves to reduce motivation to speed.ApplicationWidespread use of the ATM gauge may result in reduction in number and intensity of accidents.     

Effects of weather and weather forecasts on driver behaviour

Winter-time slipperiness is a considerable source of elevated road accident risk, especially in northern countries such as Canada, Finland and Sweden. The national road administrations often offer a service to inform drivers of forthcoming weather and driving conditions in different regions. This study addressed the effects of adverse weather and traffic weather forecasts on driver behaviour in Finland. Drivers (n = 1437) answered a questionnaire on perceptions of weather, self-reported driving behaviour, pre-trip acquisition of weather information, and possible travel plan changes. The questionnaires were distributed and instantaneously collected in rural service stations in different weather and driving conditions. Data from traffic weather forecasts, automatic traffic counters and weather measurement stations concerning the same area (and road) were also collected. Acquisition of weather information for the trip was associated with low recent driving experience, increasing age, female gender, long trip in question and very poor (local) conditions perceived by the driver. Drivers who had acquired information had also made more changes to travel plans, but information acquisition did not have an effect on their on-road driving behaviour. However, they estimated prevailing risks higher than those who did not acquire weather information. Drivers generally considered the driving conditions better than the forecast, but significantly less so in darkness than in daylight or civil twilight. Leisure trips were clearly underrepresented during very poor driving conditions forecasts, suggesting that some trips are postponed as a result of adverse weather conditions or forecasts thereof. Drivers reported various kinds of compensatory behaviour during adverse conditions, including a 6–7 km/h target speed decrement. This corresponded to traffic flow speed measurements. The results suggest that the on-road driving behaviour is predominantly affected by the prevailing observable conditions, rather than traffic weather forecasts. It is suggested that if administrators wish to help drivers in adjusting their on-road behaviour in adverse weather conditions, the methods should be more local and technical by nature.     

Driving performance while using a mobile phone: A simulation study of Greek professional drivers

PurposeThe current study aims to assess the driving performance of professional drivers while using a mobile phone.Material and methodsA sample of 50 male professional drivers participated in the study. The sample was drawn conveniently from the professional drivers’ registries and the main taxi ranks. The inclusion criteria were: (a) age above 18 years, (b) possession of a driving license, (c) sufficient reading, writing, and communicating skills, (d) informed consent prior to participation. Laboratory tests were conducted using the VS500M driving simulator manufactured by Virage Simulation Inc. The intervention involved different tasks/assignments: (a) driving without using a mobile phone (Control time), (b) driving while having a conversation on the mobile phone, (Task_1), (c) driving while reading out loud text messages (Task_2) and, (d) driving while texting (Task_3). Differences in the driving performance between the control time and the time with assignments, were examined. The participants were evaluated on the followings outcome measures: (a) variation of the steering position per second, (b) following distance per second, (c) variation of the lateral lane position per second, and (d) sum of squared acceleration per second.ResultsThe analysis indicated that “variation of the steering position per second” was significantly affected by “text-message reading” [t(50) = −5.443; p < 0.0001] and “texting” [t(50) = −5.442; p < 0.0001]. A significant main effect was observed in terms of the “following distance per second” and the “variation of the lateral lane position per second” for all the three mobile phone assignments. Lastly, the “sum of squared acceleration per second” was significantly decreased during conversation on the phone [t(50) = 2.713; p = 0.009] as well as during texting [t(50) = 3.428; p = 0.001] as compared with the control time.ConclusionsThe study is among the few existing experimental studies in a country with one of the highest road fatalities in Europe but with limited evidence on road traffic behaviour. This study could guide the design of large-scale simulation studies aiming to explore the impact of mobile phone on driving behaviour.     

The relationship between leisure time and driving style in two groups of male drivers

Despite overall improvements in traffic safety levels, young male drivers continue to be over represented in accidents. In this study the association between driving style and leisure time was examined in two groups of drivers. The sample consisted of 4000 male drivers of which 2000 were 18 years old and 2000 were 28 years old. A posted questionnaire was used. The overall response rate was 51% (N = 2018). A similar factor structure of three factors with regard to driving style was identified in both groups of drivers. The factors were named Thrill, Anxiety and Anger. Despite significant differences regarding specific leisure time activities, a similar relationship between leisure time and driving style was found in the two groups of drivers particularly in relation to problem behaviours. In both groups driving related interaction with friends as well as a high paced leisure time was found to be related to a high score on the factors Thrill and Anger. In the older group of drivers cruising with friends was associated with problem behaviours such as smoking pot and doing drugs. Results indicate a need for early intervention enhancing safe behavioural choices thereby preventing unsafe behaviours to become permanent behavioural strategies in life.     

Keep on cruising: Changes in lifestyle and driving style among male drivers between the age of 18 and 23

Despite recent improvements in general road safety levels, young male drivers in most western countries continue to be overrepresented in road traffic accidents. Lifestyle related motivational factors are a key element in the young male driver problem. Based on 379 posted questionnaires completed by the same male drivers at the age of 18 and again at the age of 23, this study examined changes in the relationship between lifestyle and driving style over a 5 year period. A number of changes in car use, driving style and engagement in different leisure time activities were found. Cruising was related to an extrovert social life as well as problem behaviours such as drink driving. At the age of 18 cruising was a part of the normal social life of the majority of the participants. However, while most drivers reduced their level of cruising as well as related problem behaviour over time, a smaller group still showed a similar life style at the age of 23. The study confirmed the importance of lifestyle related motivational factors for driving behaviour among young drivers.     

Investigating the motivational factors influencing drivers intentions to unsafe driving behaviours: Speeding and overtaking violations

Achieving road safety depends on driver attitudes and behaviours in handling the vehicle on roads. The availability of good road, improvement of vehicle designs and drivers experience lead to reduction in crashes but not prevention of crashes. The study aims to predict the drivers’ intentions towards speeding and overtaking violations when under the influence of motivational factors using belief measure of TPB and DBQ variables. To achieve this, questionnaires were randomly administered to a sample of Ghanaian drivers (N = 354) who held valid driving licenses. This study applied regression techniques. The result shows that the components of TPB and DBQ variables were able to predict drivers’ intentions towards speeding and overtaking violations. The study further shows that components of TPB made larger contributions to the prediction of divers’ intentions to speeding and overtaking than the DBQ. Further analysis revealed that, in the prediction of drivers’ intentions, speeding attitude was the most frequent violations compared to overtaking. The drivers tend to involved in overtaking violations when they perceived the driving motivations would enhance the performance of the behaviour. Additionally, control belief has been the strongest predictor of drivers’ intentions under the influence of motivations to speeding and overtaking violations. It appeared that the drivers who intended to involve in speeding and overtaking violations had strong beliefs in the factors and are more likely to violate based on their beliefs. The practical implications of the findings for the development of interventions to promote road safety and positive changes are also discussed.     

Contextual Design for driving: Developing a trip-planning tool for older adults

Independent living depends on mobility, and mobility depends on driving, particularly for people 65 years and older. The longer older adults can safely drive, the longer they can independently run errands, shop, exercise, and maintain social networks. Age-related decline of perceptual, motor, and cognitive abilities can undermine the mobility and driving safety of older drivers. Data from driving simulators, on-road tests, surveys, and crash reports describe the driving safety and mobility challenges of older adults, but these methods offer a limited view of these challenges and fail to indicate design solutions. Contextual Design—a combination of Contextual Inquiry interviews, model building, and affinity diagrams—offers a complementary approach to uncover challenges that older adult drivers’ experience. For two weeks, 39 drivers age 65 and above, had their vehicles instrumented to collect driving and video data. Applying Contextual Design to these data showed that older drivers in urban and rural settings faced different mobility challenges and adopted various strategies to mitigate risk: older drivers often involved their spouse or passenger in the driving task, avoided certain driving maneuvers such as left turns, avoided unfamiliar or poorly lit roads at night, and planned trips to avoid risky driving situations. Ridesharing and trip planning emerged as important strategies to improve the safety and mobility of older drivers. Ridesharing could serve as a potential solution to prolong mobility; however, factors such as wait time, scheduling conflicts, costs, and trust were concerns for older drivers. A paper prototype was developed to validate the driving challenges faced by older drivers, and guide the development of a customized web-based trip-planning tool. The trip-planning tool could help older drivers make safer route choices by offering routes with fewer driving challenges, thereby enhancing their driving safety, mobility, and independence.     

The effect of tire grip on learning driving skill and driving style: A driving simulator study

There is a need for training methods that improve the driving skill and driving style of novice drivers. Previous research in motor learning has shown that degrading the task conditions during practice can enhance long-term retention performance. Inspired by these findings, this study investigated the effects of the tire-road friction coefficient on learning a self-paced lane-keeping task in a driving simulator. A sample of 63 young and inexperienced drivers were divided into three groups, low grip (LG), normal grip (NG) and high grip (HG), who practiced driving with a friction coefficient of 0.45, 0.90, and 1.80, respectively. All groups drove six 8 min sessions on a road with curves in a rural environment: four practice sessions, an immediate retention session, and a delayed retention session on the next day. The two retention sessions were driven with normal-grip tires. The results show that LG drove with lower speed than NG during practice and retention. Transferring from the last practice session to the immediate retention session, LG’s workload decreased, as measured with a secondary task, whereas HG’s workload increased. During the immediate retention session, LG had less road departures than HG, but HG drove closer to the lane center in curves than the other two groups. HG reported elevated confidence during practice, but not in retention. In conclusion, this simulator-based study showed that practicing with low-grip tires resulted in lower driving speeds during retention tests, an effect which persisted overnight. These results have potential implications for the way drivers are trained.     

Effect of a short nap on the alertness of young drivers: Repercussion on the perception of motorcycles according to extent of the useful visual field of the driver

The objectives of this study are to analyze the effect of a short nap on the level of alertness and on the drivers’ ability to detect the motorcyclists on the road according to the size of his/her useful visual field (UVF).Nineteen participants (m = 21 years old) carried out a driving task with a simulator, after taking a short nap (30 min) in the vehicle or not. They had to distinguish the colour change of a signal on a vehicle they were following and to detect a motorcycle which briefly appeared on the road at different eccentricities.Drivers with a limited UVF are those who detect the fewest motorcycles. Taking a short nap before the driving does not have any significant effect on data related to vision (motorcycles and signals detected), driving and alertness state ((α+θ)/β). There is a linear relationship between the size of the UVF and the ability to detect the motorcycle appearing in the left outside mirror.The implications of the results concerning the short nap as a countermeasure to a decrease in alertness and the perception of motorcycles according to extent of the useful visual field of the driver are discussed in terms of road safety.