The relationship between cognitive function and hazard perception in younger drivers

Driving is a complex task; with research suggesting cognitive function plays a significant role in driver behaviour. Recent studies have investigated the role of cognitive function in younger drivers who are experiencing brain maturation and are over-represented in crash statistics. Emerging evidence suggests poor cognitive functioning is one explanation for this high crash risk. For younger drivers, the relationship between cognitive function and driving ability has been consistently shown for speeding and lane deviations. However, the driving skill most consistently linked to crash involvement is hazard perception, which is the ability to anticipate and respond to potentially dangerous traffic situations. The aim of this study was to investigate the cognitive correlates of hazard perception in younger drivers. Seventy-nine undergraduate students completed a hazard perception test and a battery of cognitive tests that have previously demonstrated a relationship with safe driving. The newly created hazard perception test measured accuracy of hazard identification, response times when anticipating the hazard, and response times when taking action to avoid the hazard. Hazard perception accuracy was significantly related to visuo-spatial skills, executive functioning and global cognitive status. Anticipation response times were significantly related to inhibitory control, with no significant relationship found between cognitive function and action response times. These findings are discussed in line with limitations in the study. Future research into the role of specific cognitive domains could lead to the enhancement of hazard perception testing for licensing with cognitive training and assessment, with the potential to reduce the crash risk of vulnerable younger drivers.     

The implications of low quality bicycle paths on the gaze behaviour of young learner cyclists

In a recent study, Vansteenkiste et al. (2014) described how low quality bicycle paths cause an apparent shift of visual attention from distant environmental regions to more proximate road properties. Surprisingly, this shift of visual attention was not accompanied by an adaptation in cycling speed. The current experiment investigated to what extent these findings are applicable for young learner bicyclists (aged 6–12 years). Since young learner bicyclists do not yet have mature visual and motor skills, it was expected that the implications of a poor road surface would be larger for them than for experienced adult bicyclists. In general, children looked less to the road and more to task irrelevant regions, but the magnitude of the shift of visual attention when cycling on a low quality bicycle track was similar to that of adults. Although children cycled slower than adults, they did not cycle slower on the low quality track compared to the high quality track. Overall, our results suggest that children displayed a different visual-motor strategy than adults, characterized by lower cycling speeds and a different visual behaviour, and that they responded in a similar way to a low quality bicycle path as adults.     

Scores on a new hazard prediction test are associated with both driver experience and crash involvement

Hazard perception skill has been found to be associated with drivers’ crash risk. This skill has typically been measured using computer-based response-time hazard perception tests, in which drivers indicate the earliest point that they detect a potential hazard in video clips of traffic filmed from a driver’s perspective. In recent years, researchers have suggested an alternative type of measure, known as a “hazard prediction test”, in which each test item is a traffic clip that stops (typically cutting to black) just before a hazardous incident unfolds. Drivers taking the test have to predict what happens next in the clip. Measures of this kind have been found to distinguish between high risk (novice) and lower risk (experienced) driver groups, and have been argued to offer several advantages over traditional response-time hazard perception tests. However, a key strength of the response-time hazard perception test is that assessments using this format have been found to predict crash involvement. The same has not yet been demonstrated for hazard prediction tests, raising questions about their validity. In the present research, we created a new hazard prediction test using Australian traffic scenes. In our version of the test, drivers’ scores were based on how many plausible predictions they were able to generate for each traffic clip. We established validity evidence for the test scores in two studies with separate samples, using two different versions of the test (long vs. short) with different response modes (verbal vs. written). As well as distinguishing between novice and experienced driver groups, test scores were also associated with self-reported crash involvement in both studies. We also found a significant correlation between hazard prediction test scores and scores in an established response-time hazard perception test. These findings support the proposal that scores on the hazard prediction test are a valid measure of hazard perception skill.     

A method to improve the hazard perception of young novice drivers based on Bandura’s observational learning theory: Supplement to expert commentary training

Compared with experienced drivers, young novice drivers are more likely to have traffic accidents. The main reasons are that they lack experience, their hazard perception is weak, and their visual search strategy is underdeveloped. Research shows that hazard perception training can improve the visual search strategy of young novice drivers and enhance their hazard perception ability. We propose that a driver's visual search behaviour, like any other action, can be developed by observing the behaviour of a role model. In an experiment based on a driving simulator, we clustered the visual search paths of 20 experienced drivers, selected the drivers with the best visual search behaviour, and obtained visual search path video footage to produce hazard perception training videos. Using these videos, we applied Bandura’s observation learning theory to train 20 young novice drivers. We call this approach “training based on experienced drivers' performance”. To determine the effects of training based on experienced drivers' performance, 20 young novice drivers were given the usual expert commentary training, and 20 young drivers were given no training. The results showed that training based on experienced drivers' performance and expert commentary training had positive effects on the average speed of young novice drivers through hazard sections. Compared with untrained young novice drivers, trained young novice drivers decreased their speed in response to dangerous road sections. Compared with young novice drivers who received expert commentary training and those who did not receive training, young novice drivers who received training based on experienced drivers' performance showed significant improvements in visual search. These results suggest that training based on experienced drivers' performance can help young novice drivers improve their hazard perception, especially in visual aspects. This training method can complement existing training methods for young novice drivers.     

危险类型对公交驾驶员危险知觉的影响

结合反应时方法和多维度驾驶风格量表,以140名公交驾驶员为研究对象,采用2（危险类型：隐藏危险、明显危险）×2（驾驶员分组：有无交通违规/事故记录）的混合实验设计考察危险类型对危险知觉的影响。结果发现：驾驶员对明显危险的反应时比隐藏危险短,无交通违规/事故记录驾驶员对明显和隐藏危险的反应时均比有交通违规/事故记录驾驶员短。控制驾驶风格后,危险类型主效应不再显著。结果表明,公交驾驶员危险知觉的特点随着危险类型不同而变化。     

Evaluating bicyclists’ risk perception using video clips: Comparison of frequent and infrequent city cyclists

Hazard and risk perception has been studied extensively among car drivers, and their link to crash involvement is established. Bicyclists, in particular, are vulnerable road users. Better understanding of their risk and hazard perception could help to improve their traffic safety.In this study, we investigated the risk perception of bicyclists in a city environment. Two groups of bicyclists were compared: 19 frequent and 19 infrequent bicyclists. Participants were shown video clips taken with a camera attached to the handlebar of a bicycle, and they were asked to continuously indicate with a slider how much caution the situation needed.The frequent cyclists had more frequent rises in the caution estimate, which suggest that they anticipated or detected more hazards than infrequent cyclists. This is in line with the classical hazard perception results, which link the car driving experience to faster and more accurate hazard perception. The overall level or caution was not directly related to the rise event rate or bicycling frequency. Those cyclists who reported typically cycling faster than others showed elevated overall level of caution on sidewalks compared with others, but there was no difference on bike paths.     

The role of ecological validity in hazard perception assessment

Hazard perception is one of the few quantifiable components of driving competency that can explain the high crash risk of novice drivers (see Horswill & McKenna, 2004). Some studies focused on investigating the stimulus part of hazard perception items by comparing several design features of the displayed traffic scenarios (e.g. Malone et al., 2012; Scialfa et al., 2013). Other empirical studies have been conducted to address the reaction part of hazard perception items (e.g. Vlakveld, 2014). Among others, existing hazard perception tests differ with respect to the ecological validity – the similarity to real-world demands – of the task that has to be completed by the participants (simple reaction, hazard localization, simulated driving, etc.). Based on the findings of general expertise research (see Glaser & Chi, 1988), the hypothesis of the present experiment was that an increased ecological validity of a hazard perception task has a positive effect on the magnitude of performance differences between more and less experienced drivers. 104 learner drivers and 51 experienced drivers were randomly assigned either to a less ecological valid version (multiple choice task) or a higher ecological valid version (reaction task) of a hazard perception test. In both conditions, the same 20 animated hazardous or non-hazardous traffic scenarios were presented. Overall, the experienced drivers outperformed the learner drivers. Principally, both of the applied versions of the test provided a criterion valid measure of driving expertise. However, increasing the ecological validity of the test by using a reaction task was especially beneficial for certain types of scenarios, leading to higher expertise-related differences. In addition, the reaction task provides response time measure as a further valid performance indicator. This allows the identification of those participants who are indeed able to detect a hazard in a certain scenario, but still have deficits in response time, compared to more experienced drivers. According to the present study, it is recommended to choose the reaction task over the multiple choice task to test hazard perception. Whether a further increase in ecological validity of the task would be useful, should be tested empirically in future research.     

The development of hazard perception: Dissociation of visual orientation and hazard processing

Eye movements are a key behavior for visual information processing in traffic situations and for vehicle control. Previous research showed that effective ways of eye guidance are related to better hazard perception skills. Furthermore, hazard perception is reported to be faster for experienced drivers as compared to novice drivers. However, little is known whether this difference can be attributed to the development of visual orientation, or hazard processing. In the present study, we compared eye movements of 20 inexperienced and 20 experienced drivers in a hazard perception task. We separately measured (a) the interval between the onset of a static hazard scene and the first fixation on a potential hazard, and (b) the interval between the first fixation on a potential hazard and the final response. While overall RT was faster for experienced compared to inexperienced drivers, the scanning patterns revealed that this difference was due to faster processing after the initial fixation on the hazard, whereas scene scanning times until the initial fixation on the hazard did not differ between groups.     

The differences in hazard response time and driving styles of violation-involved and violation-free taxi drivers

The present study aimed to investigate the relationships between taxi drivers’ traffic violations in past driving and two domains: driving skill (hazard perception skill) and driving style. Five hundred and fifty taxi drivers aged 25 – 59 were recruited to finish a video-based hazard perception test and the Chinese version of the Multidimensional Driving Style Inventory (MDSI). The relationships between hazard response time, driving style and traffic violations were examined, and the differences in hazard response times and driving styles of violation-involved drivers (n = 220) and violation-free drivers (n = 330) were compared. The results showed that taxi drivers’ traffic violations are closely related to their driving styles and hazard response time. Violation-involved drivers scored significantly higher in hazard response time and maladaptive driving styles (i.e., anxious, risky and angry styles) and lower in careful driving style than violation-free drivers. More importantly, drivers’ hazard response time and driving styles can effectively predict their violation involvement in the last 12 months with an overall classification accuracy of 66.4%. The findings provide evidence for the usefulness of video-based hazard perception tests and the MDSI in taxi driver testing and training.     

影响驾驶安全的驾驶员危险知觉研究述评

危险知觉是指驾驶员对交通情境中的潜在危险进行识别并做出反应的一种能力。目前,驾驶员危险知觉测量主要使用反应时、眼动或主观评定三种测量方法。在测量中,这三种方法各有优缺点,并出现相互结合的研究趋势。为了提高我国交通安全性,结合国外在提高驾驶员危险预期能力和改善视觉搜索模式两个方面的应用研究,未来国内研究可以在探索危险知觉的认知加工特点、影响因素及加快测量技术的商品化应用等方面加以深入。     

The interactive effect of vehicle signals and sensation-seeking on driver hazard perception

Does sensation seeking—as a personality trait that is closely related to risky driving—affect a driver's hazard perception, and if so, under what circumstances? Using hazard locations and vehicle signals as cues, this study classifies traffic situations into four types: danger ahead with cues, danger ahead without cues, danger behind with cues, and danger behind without cues. Based on these classifications, we examine the characteristics of hazard perception, decision-making criteria, sensitivity, and visual attention patterns of drivers with different sensation-seeking tendencies. Fifty-two experienced drivers were recruited for experiments in Dalian, China. Using computer, participants were shown videos taken from the driver's perspective and were asked to respond to hazards by pressing keys on the left mouse button. Their eye movements were recorded, and a multi-dimensional driving-style scale was used to divide participants into higher and lower sensation-seeking groups. The results showed that the higher sensation-seeking drivers had a lower hazard detection rate, fewer fixation counts, and shorter glances when there were cues, and they responded more slowly when there was danger ahead. For dangers ahead with cues and dangers behind without cues, the more attention the higher sensation-seeking drivers paid to the danger, the slower their response and the lower their hazard detection rate. The results indicated that higher sensation-seeking drivers have poor hazard perception in situations when there are vehicle signals as prompting clues and dangers ahead. In particular, for a danger with clues, the visual agility of the higher sensation-seeking drivers was worse than that of the lower sensation-seeking drivers. The more attention they paid to the danger the worse their hazard perception. The results of this study can provide guidance to teach drivers hazard-perception skills.     

The development and validation of a hazard perception test for Thai drivers

Thailand is a developing country with a high traffic accident fatality rate. However, few attempts have been made to understand crash risks in Thai drivers from a psychological perspective. The purpose of the present study was to develop and validate a latency-based hazard perception test for Thai drivers. The initial test comprised our full item pool of 77 clips containing traffic conflicts captured on video from the driver’s perspective on Thai roads. We evaluated the validity of this test by examining whether performance differed as a function of driving experience in a sample of 135 Thai drivers. We found that experienced drivers (n = 87) performed significantly better than novice drivers (n = 48) after adjusting for individual differences in computer mouse skill, mirroring crash risk differences between these groups. The final 30-item version of the test, which comprised the best items from the initial test, yielded novice/experienced driver differences with or without adjusting for computer mouse skill. These results offer preliminary support for the validity of the latency-based test as a measure of hazard perception ability in Thai drivers.     

Children's sensitivity to traffic hazard in peripheral vision

Although children and adults have poorer peripheral vision than foveal vision there is contradictory evidence about the developmental changes that occur in peripheral sensitivity. Previous research on detections of traffic hazard has not, however, provided any evidence that peripheral vision is implicated in the particualr vulnerability of children to pedestrain accidents. In the absence of differences in peripheral detections it was hypothesized that children may nevertheless be less efficient than adults in utilizing information presented in the periphery. Road traffic scenes depicting vehicles in potentially hazardous and non-hazardous positions for road crossings were presented to adults and to childre, aged 7, 9, and 11. Results confirmed that children were relatively no poorer than adults at hazard detection in peripheral vision than in foveal vision, but indicated that they were marginally poorer at utilizing information presented in the periphery, as measured by a vehicle recognition test. Against expectd developmental trends 9-year-olds were as fast as adults at hazard detection, but no different from the other groups of children in recognition performance. Evidence that information detected and assimilated in peripheral vision does not contribute to the high pedestrian accident rates of children comes from the absence of any sex differences favouring girls. Since girls have considerably lower accident rates than boys, it would have been expected that both their detection and recognition performance would have been higher.     

驾驶经验和危险类型对年轻驾驶员危险知觉的影响

结合反应时和眼动测量方法,采用驾驶经验分组2（年轻新手驾驶员,年轻有经验驾驶员）× 危险类型2（明显危险,隐藏危险）的混合实验设计,探索年轻驾驶员危险知觉的经验优势是否随着危险类型的不同而变化。使用一个基于真实交通情境视频的驾驶员危险知觉任务,对27名年轻新手驾驶员和22名年轻有经验驾驶员进行测试,并使用Tobbi T120记录眼动数据。结果发现,总体上,年轻新手驾驶员对潜在道路危险的反应次数比年轻有经验驾驶员更少,反应时间也更慢。两组驾驶员反应时间的差异,随着危险类型的不同而来源于不同的加工阶段。具体来说：一方面,年轻新手驾驶员对明显危险的反应时间慢,是因为他们对该类危险的评估时间长。另一方面,年轻新手驾驶员对隐藏危险的反应时间慢,是因为他们对该类危险的识别时间长。两组驾驶员对危险的平均注视时间受测试中危险类型的影响但不受驾驶经验的影响。这些研究结果表明,在对年轻新手驾驶员进行危险知觉训练或测试时,应重视危险类型对他们危险知觉的影响。     

A brief and unsupervised online intervention improves performance on a validated test of hazard perception skill used for driver licensing

Drivers who have higher levels of hazard perception skill also tend to have fewer crashes. Training designed to improve this skill has therefore been proposed as a strategy for reducing crash risk. To date, however, hazard perception training has only been evaluated in supervised settings. This means that improvements in hazard perception skill resulting from such training may not generalize to unsupervised situations, which may limit opportunities for large scale roll-out via automated delivery methods. In the present study, we investigated whether a brief video-based training intervention could improve hazard perception skill when drivers completed it online without supervision. The training involved drivers watching videos of traffic scenes, while generating a commentary of what they were searching for, monitoring, and anticipating in each scene. Drivers then compared their own commentary to a pre-recorded commentary generated by an expert driver, hence allowing for performance feedback without an instructor present. A convenience sample of 93 drivers (who did not receive any performance-related incentives) participated in a randomized control study. The training was found to significantly improve response times to hazards in stimuli from the official hazard perception test used for driver licensing in Queensland, Australia, which is known to predict crash involvement. That is, the training was effective in improving hazard perception skill (Cohen’s d = 0.50), even though participants were aware that no one was monitoring the extent to which they engaged in the intervention. Given that the training could, in principle, be deployed at scale with minimal resources (e.g. via any online platform that allows video streaming), the intervention may represent a practical and effective opportunity to improve road safety.     

Other road users’ adaptations to increase safety in response to older drivers’ behaviour

Changes in physical and cognitive abilities not only challenge the driving ability of older adults, in some situations age-related changes in driving behaviour require other road users to adapt their behaviour to maintain a safe traffic situation. In this study, we aimed to map age-related differences in driving behaviour and assess the impact on other road users. A group younger and a group older adults drove four different routes containing challenging situations (e.g., merging into motorway traffic) in a driving simulator while measures of driving behaviour were collected. Other road users’ deceleration responses to the driver’s behaviour were also collected as a measure of behavioural adaptation. Our results showed similar driving performance between young and older drivers when task complexity was low, but reduced performance in older drivers when tasks requirements increased. Lower driving speed and longer waiting times that were observed in older drivers can be interpreted as compensatory behaviour aimed at creating more time to lower task requirements. Crucially, in a non-time critical situation this compensatory behaviour was found to be successful, however in a time-critical situation (merging onto a motorway) this strategy had negative side effects because other road users had to decelerate in order to keep a safe distance. Our results show the importance of anticipation and adaptation by other road users for the success of older driver’s strategies and traffic safety.     

自我评估的能力与驾驶经验对危险知觉的影响

结合反应时和眼动研究方法,采用驾驶经验2（新手,有经验）×自我评估的能力2（高,低）×危险类型2（明显,隐藏）的混合实验设计,探索驾驶员驾驶能力的自我评估和驾驶经验对危险知觉及视觉注意的影响。采用驾驶能力量表和基于动态交通视频的危险知觉任务对86名驾驶员测试,并使用Tobbi T120记录眼动数据。结果发现,新手和有经验驾驶员自我评估的能力与危险知觉反应时间之间相关不显著,这说明两组驾驶员对自己驾驶能力的认识和评估不准确。有经验驾驶员对两类危险的反应比新手快。新手自我评估的能力过高,他们对两类危险的反应比同龄驾驶员和有经验驾驶员慢。然而,有经验驾驶员自我评估的能力与危险知觉反应时间之间不存在显著差异。此外,与新手相比,有经验驾驶员对两类危险的首次注视较快,总注视时间更长。与同龄驾驶员相比,新手自我评估的能力过高,他们对危险的首次注视较慢,对危险的总注视时间更少。这些研究结果表明,新手自我评估的能力过高,可能会提高他们的风险接受阈限,由此降低了他们对危险的反应速度。未来驾驶训练应当采取措施减少新手对驾驶能力的自我评估偏见,改善他们的视觉搜索模式以降低事故风险。     

Safety of bicyclists in roundabouts with mixed traffic: Video analyses of behavioural and surrogate safety indicators

Although converting an intersection into a roundabout has been shown to result in fewer injury accidents for both motor vehicle drivers and pedestrians, the effect on bicyclists’ safety is unclear or even negative. This study focuses on roundabouts without bicycle facilities (i.e., mixed traffic conditions) and makes use of semi-automated video observation software with the aim of analysing bicyclists’ behaviour and safety on roundabouts with different diameter. Four urban roundabouts in Belgium are observed. Interactions between bicyclists and other vehicles are analysed using speed, lateral position and five indicators to describe the closeness of interactions (TTC_min, PET, T_{2 min}, lateral overtaking proximity and minimum distance headway). Additionally, the lateral position and riding speed of bicyclists that are in interaction with other vehicles is compared with the behaviour of bicyclists that are not in interaction with other vehicles.The behavioural analysis revealed that regardless of the type of condition (free-flow bicyclists or different interactions bicyclist-car), bicyclists always ride faster on roundabouts with big diameter and slower on roundabouts with small diameter. Moreover, bicyclists ride closer to the central island on roundabouts with big diameter compared to roundabouts with small diameter for all the conditions analysed.The analysis of surrogate safety indicators (TTC_min, PET, T_{2 min}) revealed that close interactions between bicyclists and cars are relatively frequent at both small and big roundabouts. The percentages of close interactions are more or less equal for roundabouts with big diameter (7.86% of observed interactions) and roundabouts with small diameter (8.24%). The analysis of the indicators to describe the closeness of interactions also showed that the closest interactions at roundabouts are all situations where the bicyclist has a leading role. The analysis of the most common types of close interactions revealed indeed that the most common close interactions are interactions where the bicyclist is entering the roundabout. The analysis of lateral overtaking proximity showed that bicyclists who overtake a car take smaller lateral overtaking proximities compared to cars overtaking a bicyclist. The analysis of minimum distance headway finally revealed that bicyclists who ride behind a car take smaller distance headways compared to cars driving behind a bicyclist.     

Young drivers’ perception of hazards: Variation with experience and day versus night

Young novice drivers have a relatively high crash risk for several years following initial licensing, and while all drivers are at greater risk at night, the night-time increase is greater for inexperienced drivers. Poor hazard perception has been identified as an important contributor to inexperienced drivers’ risk, but research on day-night differences in hazard perception for drivers varying in experience is lacking. This exploratory study investigated the nature of hazards reported by young inexperienced drivers versus more experienced and slightly older drivers. Hazards were not pre-identified by researchers; participants were simply provided with a general definition of ‘hazard’. Analysis focused on how experience level affected qualitative differences in the kinds of hazards reported, with particular focus on day-night differences.The 53 participants ranged in driving experience from learners through to 5+years post licensing, and in age from 16 to 30 years. They viewed 14 day- and night-time video clips of a diverse range of driving situations, pausing the video whenever they identified a hazard and then explaining why they had paused it at that point. Their responses were recorded. Content analysis of responses showed that more experienced drivers reported visibility-related hazards significantly more often than inexperienced ones, and significantly more so at night. They also commented significantly more on hazards related to tight bends in the road and significantly less on hazards concerning compliance with rules. Comments tended to be fewer with higher vehicle speeds, particularly for the least experienced drivers.Results are discussed in terms of how experience-related differences in drivers’ cognitive schemata and mental models are likely to affect hazard perception and crash risk, particularly at night. Some implications for driver training and license testing are suggested.