Using the Lane-Change Test (LCT) to Assess Distraction: Tests of Visual-Manual and Speech-Based Operation of Navigation System Interfaces

The Lane Change Test (LCT) is an easy-to-implement, low-cost methodology for the evaluation of the distraction associated with performing invehicle tasks while driving (Mattes, 2003). In the present study, the LCT was used to assess driving performance when drivers completed navigation tasks using visual-manual or speech-based interfaces. Drivers performed two types of navigation tasks at two levels of difficulty. The results provide support for the LCT as an effective measure of distraction for both types of interface. It is recommended that the LCT procedure incorporate additional measures beyond the current mean deviation measure. Two measures are suggested: Lane Change Initiation, which reflects the aspects of driving having to do with detection and response delay as a result of distraction, and a measure of task duration to account for risk exposure

Is it reliable to assess visual attention of drivers affected by Parkinson's disease from the backseat?—a simulator study

BACKGROUND: Current methods of determining licence retainment or cancellation is through on-road driving tests. Previous research has shown that occupational therapists frequently assess drivers' visual attention while sitting in the back seat on the opposite side of the driver. Since the eyes of the driver are not always visible, assessment by eye contact becomes problematic. Such procedural drawbacks may challenge validity and reliability of the visual attention assessments. In terms of correctly classified attention, the aim of the study was to establish the accuracy and the inter-rater reliability of driving assessments of visual attention from the back seat. Furthermore, by establishing eye contact between the assessor and the driver through an additional mirror on the wind screen, the present study aimed to establish how much such an intervention would enhance the accuracy of the visual attention assessment. METHODS: Two drivers with Parkinson's disease (PD) and six control drivers drove a fixed route in a driving simulator while wearing a head mounted eye tracker. The eye tracker data showed where the foveal visual attention actually was directed. These data were time stamped and compared with the simultaneous manual scoring of the visual attention of the drivers. In four of the drivers, one with Parkinson's disease, a mirror on the windscreen was set up to arrange for eye contact between the driver and the assessor. Inter-rater reliability was performed with one of the Parkinson drivers driving, but without the mirror. RESULTS: Without mirror, the overall accuracy was 56% when assessing the three control drivers and with mirror 83%. However, for the PD driver without mirror the accuracy was 94%, whereas for the PD driver with a mirror the accuracy was 90%. With respect to the inter-rater reliability, a 73% agreement was found. CONCLUSION: If the final outcome of a driving assessment is dependent on the subcategory of a protocol assessing visual attention, we suggest the use of an additional mirror to establish eye contact between the assessor and the driver. The clinicians' observations on-road should not be a standalone assessment in driving assessments. Instead, eye trackers should be employed for further analyses and correlation in cases where there is doubt about a driver's attention

Pedestrian Injury and Human Behaviour: Observing Road-Rule Violations at High-Incident Intersections

Background Human behaviour is an obvious, yet under-studied factor in pedestrian injury. Behavioural interventions that address rule violations by pedestrians and motorists could potentially reduce the frequency of pedestrian injury. In this study, a method was developed to examine road-rule non-compliance by pedestrians and motorists. The purpose of the study was to examine the potential association between violations made by pedestrians and motorists at signalized intersections, and collisions between pedestrians and motor-vehicles. The underlying hypothesis is that high-incident pedestrian intersections are likely to vary with respect to their aetiology, and thus are likely to require individualized interventions – based on the type and rate of pedestrian and motorist violation. Methods High-incident pedestrian injury intersections in Vancouver, Canada were identified using geographic information systems. Road-rule violations by pedestrians and motorists were documented at each incident hotspot by a team of observers at several different time periods during the day. Results Approximately 9,000 pedestrians and 18,000 vehicles were observed in total. In total for all observed intersections, over 2000 (21%) pedestrians committed one of the observed pedestrian road-crossing violations, while approximately 1000 (5.9%) drivers committed one of the observed motorist violations. Great variability in road-rule violations was observed between intersections, and also within intersections at different observation periods. Conclusions Both motorists and pedestrians were frequently observed committing road-rule violations at signalized intersections, suggesting a potential human behavioural contribution to pedestrian injury at the study sites. These results suggest that each intersection may have unique mechanisms that contribute to pedestrian injury, and may require targeted behavioural interventions. The method described in this study provides the basis for understanding the relationship between violations and pedestrian injury risk at urban intersections. Findings could be applied to targeted prevention campaigns designed to reduce the number of pedestrian injuries at signalized intersections

An Ontological Approach to Inform HMI Designs for Minimizing Driver Distractions with ADAS

ADAS (Advanced Driver Assistance Systems) are in-vehicle systems designed to enhance driving safety and efficiency as well as comfort for drivers in the driving process. Recent studies have noticed that when Human Machine Interface (HMI) is not designed properly, an ADAS can cause distraction which would affect its usage and even lead to safety issues. Current understanding of these issues is limited to the context-dependent nature of such systems. This paper reports the development of a holistic conceptualisation of how drivers interact with ADAS and how such interaction could lead to potential distraction. This is done taking an ontological approach to contextualise the potential distraction, driving tasks and user interactions centred on the use of ADAS. Example scenarios are also given to demonstrate how the developed ontology can be used to deduce rules for identifying distraction from ADAS and informing future designs

HASTE Deliverable 2: HMI and Safety-Related Driver Performance

The aim of HASTE is to develop methodologies and guidelines for the assessment of In-Vehicle Information Systems (IVIS). The intention is to devise an assessment regime that is independent of the design of an IVIS and that is based on an evaluation of driving performance while using the system as compared with driving performance when not using the system (baseline driving). The ambition is to provide an assessment regime which: • Is technology-independent; • Has safety-related criteria; • Is cost effective; • Is appropriate for any system design; and • Is validated through real-world testing. The objective of the experiments in this Workpackage (WP2) was to investigate the impact of IVIS task load on driving performance and safety. To achieve this, two surrogate IVISs (SIVISs) were created, one representing cognitive load and the other visual load. Using these SIVISs, it was possible to vary secondary task load systematically. Separate assessments of the effects on driving of the different types of task load were carried out, with as clean a distinction as possible between visual and cognitive load. The objective was also to identify the advantages and disadvantages of the different assessment methods (laboratory, simulator, field), and finally to identify which road types and scenarios are the most productive for testing IVIS. Different groups of drivers were used and scenarios varied in accordance with the protocol and procedure for safety assessment of IVIS as outlined in Deliverable 1 (Roskam et al., 2002). A very large set of experiments was conducted. But in one sense this was one very large multi-national unified and integrated experiment with a common goal, a common experimental protocol and common indicators. The effect of IVIS use in three distinct road categories — urban, rural, and motorway — was investigated. To do this, a total of 14 separate driving simulator experiments were conducted, with each participant experiencing only one type of S-IVIS. All seven driving simulators were used to investigate driving with both S-IVISs on a common rural road. For the most part, each simulator road type had three levels of difficultly with the most difficult being driving when some critical event was triggered (the motorway had only two levels of difficulty: without and with events). For the field (real road) studies, both types of S-IVIS were included in the drives for each participant, with the order of S-IVIS tasks counterbalanced. This was because, for these studies, there was no issue with the drivers learning what might happen in the critical events, since none were staged — all the driving was done in natural settings. The three field studies used different combinations of the road types and all roadway types were completed in a single session. The overall number of experiments, both simulator and field, was 17. A total of 527 participants were used. A large number of indicators of driving performance, particularly related to longitudinal and lateral control, were collected. Also collected was information on secondary task performance (acting as the Surrogate IVIS), both static (not driving) and dynamic (whilst driving). The indicators can be classified into: • Self-reported driving performance • Lateral control • Longitudinal control, i.e. control of speed and distance to a lead vehicle • Workload, such as physiological measures and gaze behaviour • Expert observations of driving performance Following the anaysis of this data, a meta-analysis was carried out to compare the various studies and to identify the most effective indicators. This meta-analysis was intended to single out the most powerful scenarios and to assist in showing which indicators could be dispensed with in subsequent work testing the methods in evaluating some real IVISs. The major dimensions of the study, to some extent in order of importance, were: • IVIS type, visual versus cognitive o Within IVIS type, IVIS level o Within IVIS type, Static IVIS performance versus Dynamic IVIS performance • Simulator and Laboratory studies versus Field Studies o Simulator/Laboratory type • Road category (urban, rural, motorway) o Within Road category, Road level • “Average” drivers versus Elderly drivers • UK drivers versus Portuguese drivers Findings across these dimensions were: S-IVIS Type: The two types of S-IVIS had quite different effects on driving performance. The visual task had pronounced effects in terms of steering and lateral behaviour. On the other hand, the cognitive task caused reduced lateral deviation; in other words it “improved” steering behaviour, though there was also a tendency for drivers to compensate for the task load by shifting away from the road edge. This “improvement” in steering behaviour was accompanied by an increase in glances focussed on the road ahead, at the expense of the periphery. There were indications in some of the results that the predominant negative effect of the cognitive task on driving performance was on longitudinal control in car following. S-IVIS level: Drivers were not always able to manage the trade-off between primary and secondary task, and there were many indications of driving performance being poorest when the secondary task demand was the highest. The elderly drivers were particularly poor at this task management. Static S-IVIS Performance vs Dynamic Performance: Generally, the studies found that there was an interaction between S-IVIS performance across the baseline (static) and three levels of dynamic situation (i.e. the three levels of road difficulty). This advocates the HASTE approach of requiring the driving context to be considered in assessing an IVIS. Static performance did not reliably predict dynamic performance. Simulator vs. Field: The field studies tended to pick up somewhat different effects of the systems than the simulator studies. Additionally, it has not proved possible to test elderly drivers with the visual task due to simulator sickness. This shows the value of the field tests, but also suggests that the incorporation of some additional scenarios or tests in the simulator roads should be considered. These could perhaps take the form of detecting objects in the periphery or detecting changes in the peripheral scene. Simulator Type: The broad conclusion is that the type of simulator or laboratory used in the assessment did not have an effect. Road Category: In the simulator studies, the rural road was the most diagnostic and the motorway the least diagnostic, i.e. the effect sizes from the rural road were generally larger. The urban road did not pick up any additional information that was not provided by the rural road. This means that, for simulator and laboratory assessments, the rural road can be used as the sole road category in the later work of HASTE assessing real IVIS systems as well as in the final HASTE test procedure. In the field studies with the cognitive task, the motorway produced the only indicator with a consistent effect. Road Level: Road level is an important factor. It will be sensible in the later work of the project to consider dispensing with the easiest level of the road. “Average” vs Elderly Drivers: The findings have confirmed the hypothesis proposed in Deliverable 1 (Roskam et al., 2002), that there would be severe problems for elderly drivers in using IVIS while driving, particularly at higher levels of task demand. UK vs Portugal: The controlled comparison of the British and Portuguese showed the expected effect: the Portuguese drivers exhibited riskier driving behaviours. But, reassuringly, the analysis revealed there was no interaction effect of the “country” factor. In other words, results obtained with Portuguese drivers should be as reliable as those obtained with drivers from northern Europe. As regards methodology, the results obtained form this very large set of studies confirm some of the initial decisions made in formulating the HASTE approach. There was clear value to the focus on dynamic evaluation, i.e. of looking at interaction with an IVIS while driving and of identifying the effects of that interaction on driving. Static testing cannot predict how an IVIS will affect steering behaviour or interaction with other road users. The different road levels proved their worth, particularly levels 2 and 3 of the rural road. There is also clear value to the inclusion of events (road level 3), but there is also some scope for improving the events so that the drivers are less able to adapt to their occurrence, by for example slowing down as the lead vehicle comes closer to them. There may also be scope for the inclusion of peripheral detection tasks (PDTs) in the driving task, in order to gain a better understanding of drivers’ ability to assimilate information in the periphery, which is crucial to safety. The results also confirm the value of using a very large number of indicators. Some of these indicators have turned out to be non-diagnostic and therefore can be abandoned in the next phase of the project. Others have turned out to be superfluous in that what they reveal overlaps with the diagnosis provided by other indicators. The meta-analysis has helped to sift through the indicators and test environments to identify the most powerful ones. Important conclusions from the studies are: The effect of the S-IVIS visual task on driving is very clear: increased distraction leads to problems in lateral control. • The effect of the S-IVIS cognitive task is more complex, in that some driving parameters, particularly related to steering control and lateral position appear to improve. However, this improvement seems to be an artefact of greater concentration on the road straight ahead at the expense of information acquired from the periphery. Thought needs to be given to tasks or tests that might capture this loss of information acquisition from the periphery. • Motorway driving in the various simulators and the laboratory was generally less diagnostic, than driving on other road types. • Elderly drivers exhibited very risky driving while performing IVIS tasks • The field studies provided some information that was not provided by the simulator assessments. The subsequent work in the project should consider simulator tasks that can provide analogous information