What attracts attention during police pursuit driving?

Efficient deployment of attention is important to the safe execution of tasks with a high content of visual information, such as driving. Chasing a lead vehicle is an extremely demanding and dangerous task, though little is known of the visual skills required. A study is reported that recorded the eye movements of police drivers and two control groups (novices and age‐ and experienced‐ matched controls) while watching a series of video clips of driving. The clips included pursuits, emergency response drives, and control drives (at normal speeds) around Nottinghamshire, UK. Analysis of gaze durations within certain categories of stimuli revealed that daytime pursuit drives correspond with an increase in gaze durations on a lead car (controlled for exposure), though police drivers direct their attention to other sources of potential hazards, such as pedestrians, more so than other drivers. Copyright © 2005 John Wiley & Sons, Ltd.     

Eye movements during intentional car following

Does intentional car following capture visual attention to the extent that driving may be impaired? We tested fifteen participants on a rudimentary driving simulator. Participants were either instructed to follow a vehicle ahead through a simulated version of London, or were given verbal instructions on where to turn during the route. The presence or absence of pedestrians, and the simulated time of the drive (day or night) were varied across the trials. Eye movements were recorded along with behavioural measures including give-way violations, give-way accidents, and kerb impacts. The results revealed that intentional car following reduced the spread of search and increased fixation durations, with a dramatic increase in the time spent processing the vehicle ahead (controlled for exposure). The effects were most pronounced during nighttime drives. During the car-following trials participants were also less aware of pedestrians, produced more give-way violations, and were involved in more give-way accidents. The results draw attention to the problems encountered during car following, and we relate this to the cognitive demands placed on drivers, especially police drivers who often engage in intentional car following and pursuits.     

Exploring the ability to identify visual search differences when observing drivers’ eye movements

How can we improve learner drivers’ visual skills? Much research has demonstrated that learner drivers have an impoverished spread of search during driving and that this is partly due to lack of knowledge of where and when to look, rather than simply an issue of cognitive load. Several training interventions have tried to improve scanning in these drivers with limited success. We propose that exposing drivers to examples of good and bad scanning behaviour may prove to be a useful tool in training visual search. The success of this approach, however, requires drivers to be able to distinguish between examples of good and bad scanning. To this end, two studies were undertaken where video clips of simulated driving with an overlaid eye movement trace were presented to participants who had to judge whether the eye movements were that of a learner driver or a driving instructor. Overall, participants found this discrimination task very difficult. However, the findings suggested that novice and learner drivers were able to correctly classify those eye movement traces of other learner drivers better than chance. It was also demonstrated that the ability to distinguish between the eye movements of learner drivers and driving instructors improved as the number of objective differences between the two groups increased across specific scenarios (as determined by frame-by-frame analysis using a priori categories). The results suggest that, under certain situations, drivers can extract information about the appropriateness of a particular scanning strategy just by watching a video of the eye movement trace. The implications for training interventions are discussed.     

Visual search of driving situations: danger and experience

Previous research on visual search in driving suffers from a number of problems: small sample sizes, a concentration on mundane situations, and a failure to link results to more general psychological theory. The study reported in this paper addresses these issues by recording the eye movements of a large sample of drivers while they watched films of dangerous driving situations and comparing the findings with those from more general studies on scene perception. Stimuli were classified according to the types of road shown and the degree of danger present in the scenes. Two groups of subjects took part, fifty-one young novice drivers who had just gained a full driving licence and twenty-six older more experienced drivers. Dangerous situations were characterised by a narrowing of visual search, shown by an increase in fixation durations, a decrease in saccade angular distances, and a reduction in the variance of fixation locations. These effects are similar to the concept of 'attention focusing' in traumatic situations as it is described in the literature on eyewitness memory. When road types are compared, the least visually complex rural roads attracted the longest fixation durations and the shortest angular saccade distances, while the most visually complex urban roads attracted the greatest spread of search but the shortest fixation durations. Differences between the groups of subjects were also present. Novices had longer fixation durations than experienced drivers, particularly in dangerous situations. Experienced drivers also fixated lower down and had less vertical variance in fixation locations than novices.     

A cross-cultural comparison of where drivers choose to look when viewing driving scenes

A substantial proportion of road accidents occur as a result of drivers having poor or insufficient visual search strategies. However, the majority of research into drivers visual search comes from high income Western countries where roads are relatively safe, with less being known about the visual search of drivers from non-western, low and middle income countries with much higher crash rates. This is despite the fact that cross-cultural studies have shown differences in visual search outside of driving between Western and Eastern individuals. The current study aimed to see whether these differences were present in driving by asking UK and Malaysian drivers to select where they would look when viewing images of roads from the perspective of a driver. Results showed that all drivers selected a similar number of focal objects, however there was a difference in the type of background information drivers chose to attend to, with Malaysian drivers selecting more task irrelevant information at the expense of task relevant information. Results suggest that there are cultural differences in what drivers choose to attend to which may contribute to the increased crash rate amongst drivers from low and middle income countries.     

Visual search patterns in trained and untrained novice drivers

As drivers become more experienced many changes have been observed in their patterns of visual search. Differences between novice and experienced drivers are particularly marked in demanding or hazardous road situations and this has led researchers to speculate that limitations in search patterns may explain some of the accidents where newly qualified drivers are involved. This paper reports a training intervention that informs novice drivers about their typical patterns of visual search and stresses the need for scanning multiple locations in the visual scene for sources of potential danger. Two groups of drivers were evaluated on three occasions over the course of their first year after gaining a full driving licence. The evaluations involved recording drivers' eye movements while driving a route on real roads in traffic, and while watching videos of hazardous situations. One of the groups received the training intervention before the second occasion of testing. The intervention produced notable changes in the drivers' search patterns in both situations though not all changes were still detectable at a final phase of testing three to six months after the intervention had been delivered.     

Visual information and skill level in time-to-collision estimation

Previous studies on the visual origin of time-to-collision (Tc) information have demonstrated that Tc estimates can be based solely on the processing of target expansion rate (optic variable tau). But in the simulated situations used (film clips), there was little reliable information on speed (owing to reduced peripheral vision) and distance (owing to the absence of binocular distance cues) available. In order to determine whether these kinds of information are also taken into account, it is necessary to take an approach where the subject receives a more complete visual input. Thus, an experiment conducted on a circuit under actual driving conditions is reported. Experienced drivers and beginners, who were passengers in a car, had to indicate the moment they expected a collision with a stationary obstacle to take place. Subjects were blindfolded after a viewing time of 3 s. The conditions for speed evaluation (normal versus restricted visual field) and distance evaluation (binocular versus monocular vision) by subjects were varied. The approach speed (30 and 90 km h-1) and actual Tc (3 and 6 s) were also varied. The results show that accuracy of Tc estimation increased with (i) normal visual field, (ii) binocular vision, (iii) higher speeds, and (iv) driving experience. These findings have been interpreted as indicating that both speed and distance information are taken into account in Tc estimation. They suggest furthermore that these two kinds of information may be used differently depending on the skill level of the subject. The results are discussed in terms of the complementarity of the various potentially usable visual means of obtaining Tc information.     

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。     

Driving experience and the functional field of view

Research has suggested that novice drivers have different search strategies compared with their more experienced counterparts, and that this may contribute to their increased accident liability. One issue of concern is whether experienced drivers have a wider field of peripheral vision than less experienced drivers. This study attempted to distinguish between people of varying driving experience on the basis of their functional fields of view. Participants searched video clips taken from a moving driver's perspective for potential hazards while responding to peripheral target lights. Hit rates for peripheral targets decreased for all participant groups as processing demands increased (i.e. when hazards occurred) and as the eccentricity of the target increased, though there was no interaction. An effect of experience was also found which suggests that this paradigm measures a perceptual skill or strategy that develops with driving experience.     

驾驶经验和危险类型对驾驶员危险检测的影响

结合反应时和信号检测方法,考察不同危险类型下驾驶员危险检测的特点。35名新手和35名有经验驾驶员依次完成一个反应时测试和一个信号检测任务。结果发现：新手对明显和隐藏危险的反应时间比有经验驾驶员长。与隐藏危险相比,驾驶员对明显危险的敏感性高、判断标准低。驾驶员对两类危险的反应时间长是因为他们的判断标准严格。研究结果表明,驾驶员危险检测的特点随着危险类型不同而变化。     

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.     

Driving simulator validation with hazard perception

How should we assess the comparability of driving on a road and “driving” in a simulator? If similar patterns of behaviour are observed, with similar differences between individuals, then we can conclude that driving in the simulator will deliver representative results and the advantages of simulators (controlled environments, hazardous situations) can be appreciated. To evaluate a driving simulator here we compare hazard detection while driving on roads, while watching short film clips recorded from a vehicle moving through traffic, and while driving through a simulated city in a fully instrumented fixed-base simulator with a 90 degree forward view (plus mirrors) that is under the speed/direction control of the driver. In all three situations we find increased scanning by more experienced and especially professional drivers, and earlier eye fixations on hazardous objects for experienced drivers. This comparability encourages the use of simulators in drivers training and testing.     

驾驶经验和危险类型对驾驶员危险检测的影响

结合反应时和信号检测方法,考察不同危险类型下驾驶员危险检测的特点。35名新手和35名有经验驾驶员依次完成一个反应时测试和一个信号检测任务。结果发现：新手对明显和隐藏危险的反应时间比有经验驾驶员长。与隐藏危险相比,驾驶员对明显危险的敏感性高、判断标准低。驾驶员对两类危险的反应时间长是因为他们的判断标准严格。研究结果表明,驾驶员危险检测的特点随着危险类型不同而变化。     

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.     

Fixation patterns of learner drivers with and without cerebral palsy (CP) when driving in real traffic environments

Among learner drivers with cerebral palsy (CP), driver education is problematic for those failing to fulfil their education as well as for those becoming licensed drivers. A crucial ingredient in the development of driving is the quality of the visual search. Problems increase for CP learners in those parts of training where high demands are set on visual search abilities. The aim of the study was to increase knowledge about search patterns among learners with CP in comparison with learners and experienced drivers without CP. The study was carried out in traffic by measuring eye movements and the duration and distribution of fixation. The results show that search strategies among learners with CP were less flexible than in the control groups. The results suggest a need for better methods for teaching CP learners search strategies and may provide a tool for such development.     

Obstacle avoidance under automated steering: Impact on driving and gaze behaviours

Within the context of more and more autonomous vehicles, an automatic lateral control device (AS: Automatic Steering) was used to steer the vehicle along the road without drivers’ intervention. The device was not able to detect and avoid obstacles. The experiment aimed to analyse unexpected obstacle avoidance manoeuvres when lateral control was delegated to automation. It was hypothesized that drivers skirting behaviours and eye movement patterns would be modified with automated steering compared with a control situation without automation. Eighteen participants took part in a driving simulator study. Steering behaviours and eye movements were analysed during obstacle avoidance episodes. Compared with driving without automation, skirting around obstacles was found to be less effective when drivers had to return from automatic steering to manual control. Eye movements were modified in the presence of automatic steering, revealing further ahead visual scanning of the driving environment. Resuming manual control is not only a problem of action performance but is also related to the reorganisation of drivers’ visual strategies linked to drivers’ disengagement from the steering task. Assistance designers should pay particular attention to potential changes in drivers’ activity when carrying out development work on highly automated vehicles.     

Anticipatory and control processes in the interaction with secondary tasks while driving

The paper describes an experiment where anticipatory processes in the interaction with secondary tasks while driving could be explicitly identified and contrasted to control processes during the engagement in the secondary task. A special experimental set-up in a driving simulator environment was created that allows drivers to deliberately decide whether they want to be distracted or not depending on the driving situation and the expected development of that situation. As indicators for a situation-adaptive interaction with secondary tasks parameters from driving behaviour, secondary task performance and visual behaviour were analyzed. A study with 24 test drivers revealed that drivers are, in general, able to interact with a secondary task in a situation-aware manner. For example, drivers rejected more secondary tasks in already highly demanding situations or tried to delay the beginning of the task. During secondary task performance drivers observed the situational development with short control glances back to the road and adapted their speed. The analysis of driving errors revealed that rejecting a task in an already highly demanding driving situation is an effective strategy to maintain an adequate level of driving safety. However, some critical factors were identified that might hinder the driver from executing such strategies. Several recommendations for supporting the driver on this issue are given.     

Using physiological and behavioral measurements in a picture-based road hazard perception experiment to classify risky and safe drivers

Every year, a considerable number of people got injured or even lost their lives in road traffic accidents. To decrease the number of fatalities and injuries, researchers are seeking methods to identify and restrain drivers before the happening of actual traffic accidents, who possess dangerous driving behaviors and may cause road traffic accidents. Such methods are usually exploited to decide drivers’ fitness to drive—an indicator to describe whether they are fit for driving. The aim of this study is to measure drivers’ physiological and behavioral responses to road hazards and to extract features from measurements for further classification of risky and safe drivers. 42 drivers participated in a picture-based road hazard perception experiment, where electroencephalography (EEG), electrodermal activity (EDA), behavioral responses to road hazards, multidimensional driving style inventory (MDSI) questionnaire, and demographic information were recorded. Results indicated that 5 specific physiological features regarding to road hazard perception showed significant differences between risky and safe drivers. Subsequently, participants were classified into risky or safe drivers group by applying only the 5 features. 81.82% and 77.78% accuracy of classification were attained for risky and safe drivers, respectively. It was evidenced that using physiological and behavioral responses to evaluate drivers’ road hazard perception might be utilized as a tool to measure drivers’ fitness to drive. For further studies, improvements to future experiment design were discussed.     

Young adult drivers' sensitivity to changes in speed and driving mode in a simple vehicle simulator

The study was done to check replication of changes in sensitivity with a simple simulator as had been obtained in an experiment using the real road situation. Another purpose was to control simulator sickness which could have confounded data from testing with a simulator or in actual driving. Sensitivity of the drivers (72 healthy young adults, M age = 24 yr., SD = 5) while performing the driving task was measured in terms of subjective ratings of simulator sickness and affect, and physiological measures (i.e., galvanic skin responses and skin temperature) at different driving speeds and in driving mode conditions, using a simple vehicle simulator. Analysis showed measures of drivers' state, including simulator sickness, physiological indices, and subjective reports, increased with driving speed (30 --> 90 -->120 km/hr.) and driving mode change from the regular speed to sudden increasing to sudden decreasing speeds. Particularly, the results suggest that the increased autonomic nervous activation induces increase of rated simulator sickness. Based upon the same tendency in change of the simulator sickness and physiological state with driving speed and driving mode conditions, it was concluded that, if the results obtained from the simulator experiment can be generalized to the real situation, the simulator sickness must be considered a confounding factor. The results also suggest that the changes in human sensitivity are dependent upon aspects related to speed of a vehicle and driving mode.     

An online hazard perception training course reduces heavy braking,speeding, and over-revving rates during everyday driving

In essence, driver training involves learning the skills required to drive safely and avoid dangerous events. However, in traditional on-road driver instruction, drivers virtually never accrue experience of the most significant types of events that they are learning to avoid: crashes. One means of providing this experience safely is to present novice drivers with video clips of real crashes, as part of structured learning exercises. A six-week automated online hazard perception training course for drivers, incorporating evidence-based training methods and over a hundred crash clips, was previously found to improve novice drivers’ hazard perception skill, which is known to be an important attribute for avoiding crashes. However, since hazard perception was measured using computer-based methods, the possibility remained that the training effect might not transfer to actual driving. We report a randomized control trial in which novice drivers were recruited to assess everyday driving behaviour objectively, using g-force triggered dashcams and GPS trackers installed in their vehicles. On-road data were collected for a one-month baseline period, and for a further two months after half of the sample completed the hazard perception training course. Drivers who completed the course significantly reduced their rate of heavy-braking events, their speeding behaviour, and their rate of over-revving events. These findings support the proposal that a relatively inexpensive and highly scalable hazard perception training intervention can improve on-road driving behaviour, with the clear potential to impact real-world driver safety.