David Crundall

What happens next? Predicting other road users’ behaviour as a function of driving experience and processing time

Hazard perception is one of the most important facets of driving and if the appropriate diagnostic tool is used it can discriminate between novice and experienced drivers. In this study video clips of actual driving scenarios were shown to novice and experienced drivers. The clips were stopped just prior to hazard onset and either the screen went black or the final still image stayed on the screen. Participants were then asked five questions about what happened next. This variant of the hazard perception test allowed the influence of processing time to be included and the level of situation awareness to be measured. Experienced drivers significantly anticipated more correct hazardous outcomes than novice drivers when the screen went black. Novice drivers benefited from the extra processing time afforded by the image remaining on the screen and significantly anticipated more hazards when the image remained on the screen than when it went black. The findings indicate that when processing time is manipulated, hazard perception accuracy reveals experiential differences. These differences are discussed with reference to hazard perception and situation awareness. This research informs the current controversy over whether hazard perception is a good diagnostic tool for driving performance. It identifies potential confounds in previous work and demonstrates that experiential differences can be found if the appropriate tests are used. Further, it suggests improvements for new hazard perception tests.

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.

Attending overtaking cars and motorcycles through the mirrors before changing lanes

Right of way violation crashes are the most common type of accidents that motorcyclists face. This study assessed right of way decisions in scenarios which require noticing whether there is traffic from behind that is about to overtake. A test was created which presents participants clips with a wide field of vision (from a drivers perspective in a moving vehicle), with mirror information inset that allows either cars or motorcycles that are about to overtake, to be attended. Novice and experienced car drivers, and dual drivers (with both car and motorcycle experience), watched these clips while their eye movements were monitored. The results indicated that in the rear-view and the right-side mirrors, and in the right hand lane, conflicting motorcycles garnered more attention than conflicting cars. This pattern however was particularly driven by the dual drivers group. Additionally, novice drivers and dual drivers made more use of the right side mirror than the experienced drivers. Dual drivers also made more use of the rear view mirror than experienced drivers. Finally, significant positive correlations that were found between percentages of safe manoeuvres and measures of visual search provide direct evidence demonstrating that the frequency of risky manoeuvres was indeed larger in those cases where less time was spent gazing at the mirrors, indicating that the additional attention devoted to process conflicting vehicles contributes to reduce risky manoeuvres. The general pattern of results also provides some indirect support that non-motorcyclists drivers are more likely to have Look But Fail To See errors with conflicting motorcycles than motorcyclist drivers.

Visual Attention While Driving: Measures of Eye Movements Used in Driving Research

Publisher Summary nThe information that a driver uses is predominantly visual, and wide ranges of specific driving behaviors, from navigation to anticipation of hazardous events, are primarily dependent on the optimum deployment of attention through overt eye movements. Essentially, eye movements consist of two primary events: fixations and saccades. Fixations are periods of relative stability, during which the eyes focus on something in the visual scene. Saccades are rapid, ballistic jumps of the eye that separate the fixations and serve to orient the focus of the eyes from one point of interest to another. The simplest conception of whether an individual has looked at a certain object in a scene is whether the eye coordinates recorded by an eye tracker are coincident with the world coordinates of the object. This can be calculated automatically for eye movements to static images, where the precise coordinates of an object are easily defined and related to the eye position coordinates. Many eye tracking software packages allow areas of interest (AOIs) to be generated for particular pictures, which allow automatic calculation of when individuals look at specific objects. These AOIs are regions of a visual image that are defined by two-dimensional (2D) coordinates in the viewing plane and thus allow the software to identify fixations that fall within their boundaries.Publisher Summary The information that a driver uses is predominantly visual, and wide ranges of specific driving behaviors, from navigation to anticipation of hazardous events, are primarily dependent on the optimum deployment of attention through overt eye movements. Essentially, eye movements consist of two primary events: fixations and saccades. Fixations are periods of relative stability, during which the eyes focus on something in the visual scene. Saccades are rapid, ballistic jumps of the eye that separate the fixations and serve to orient the focus of the eyes from one point of interest to another. The simplest conception of whether an individual has looked at a certain object in a scene is whether the eye coordinates recorded by an eye tracker are coincident with the world coordinates of the object. This can be calculated automatically for eye movements to static images, where the precise coordinates of an object are easily defined and related to the eye position coordinates. Many eye tracking software packages allow areas of interest (AOIs) to be generated for particular pictures, which allow automatic calculation of when individuals look at specific objects. These AOIs are regions of a visual image that are defined by two-dimensional (2D) coordinates in the viewing plane and thus allow the software to identify fixations that fall within their boundaries.

The Deceleration Detection Flicker Test: A measure of experience?

A new driving-related test is described, which provides a simple procedure to investigate a wide range of distraction and visual attention issues in driving. It requires participants to divide attention between multiple sources of potential hazard within a driving scene. The primary task requires a response when the perceived headway to a car ahead diminishes across a series of static images. Two experiments used different secondary tasks to demonstrate that central task performance is sensitive to driver experience, with highly experienced drivers better able to notice a change in apparent headway to the lead vehicle. Furthermore, background visual complexity, such as visually cluttered urban roads compared to sparser rural roads, exacerbates the experiential differences. The results suggest that the Deceleration Detection Flicker Test taps into a real driving-related skill and may provide a useful methodology for future investigation of a wide range of visual processing issues in driving research.

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 motorcyclists 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.

Visual Attention While Driving

Publisher Summary nThe information that a driver uses is predominantly visual, and wide ranges of specific driving behaviors, from navigation to anticipation of hazardous events, are primarily dependent on the optimum deployment of attention through overt eye movements. Essentially, eye movements consist of two primary events: fixations and saccades. Fixations are periods of relative stability, during which the eyes focus on something in the visual scene. Saccades are rapid, ballistic jumps of the eye that separate the fixations and serve to orient the focus of the eyes from one point of interest to another. The simplest conception of whether an individual has looked at a certain object in a scene is whether the eye coordinates recorded by an eye tracker are coincident with the world coordinates of the object. This can be calculated automatically for eye movements to static images, where the precise coordinates of an object are easily defined and related to the eye position coordinates. Many eye tracking software packages allow areas of interest (AOIs) to be generated for particular pictures, which allow automatic calculation of when individuals look at specific objects. These AOIs are regions of a visual image that are defined by two-dimensional (2D) coordinates in the viewing plane and thus allow the software to identify fixations that fall within their boundaries.Publisher Summary The information that a driver uses is predominantly visual, and wide ranges of specific driving behaviors, from navigation to anticipation of hazardous events, are primarily dependent on the optimum deployment of attention through overt eye movements. Essentially, eye movements consist of two primary events: fixations and saccades. Fixations are periods of relative stability, during which the eyes focus on something in the visual scene. Saccades are rapid, ballistic jumps of the eye that separate the fixations and serve to orient the focus of the eyes from one point of interest to another. The simplest conception of whether an individual has looked at a certain object in a scene is whether the eye coordinates recorded by an eye tracker are coincident with the world coordinates of the object. This can be calculated automatically for eye movements to static images, where the precise coordinates of an object are easily defined and related to the eye position coordinates. Many eye tracking software packages allow areas of interest (AOIs) to be generated for particular pictures, which allow automatic calculation of when individuals look at specific objects. These AOIs are regions of a visual image that are defined by two-dimensional (2D) coordinates in the viewing plane and thus allow the software to identify fixations that fall within their boundaries.

The impact of map orientation and generalisation on congestion decisions: a comparison of schematic-egocentric and topographic-allocentric maps

Map information for drivers is usually presented in an allocentric-topographic form (as with printed maps) or in an egocentric-schematic form (as with road signs). The advent of new variable message boards on UK motorways raises the possibility of presenting road maps to reflect congestion ahead. Should these maps be allocentric-topographic or egocentric-schematic? This was assessed in an eye tracking study, with participants viewing maps of a motorway network in order to identify whether any congestion was relevant to their intended route. The schematic-egocentric maps were responded to most accurately with shorter fixation durations suggesting easier processing. In particular, the drivers entrance and intended exit from the map were attended to more in the allocentric maps. Individual differences in mental rotation ability also seem to contribute to poor performance on allocentric maps. The results favour schematic-egocentric maps for roadside congestion information, but also provide theoretical insights into map-rotation and individual differences. Statement of Relevance: This study informs designers and policy makers about optimum representations of traffic congestion on roadside variable message signs and, furthermore, demonstrates that individual differences contribute to problems with processing certain sign types. Schematic-egocentric representations of a motorway network produced the best results, as noted in behavioural and eye movement measures.