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The Effectiveness of Safety Campaign VMS Messages - A Driving Simulator Investigation
Get PDFThis report outlines an off-road trial of the effectiveness of Safety Campaign Messages (such as “Watch Your Speed”) sometimes displayed on Variable Message Signs (VMS) throughout the U.K.’s motorway network. Eighty drivers took part in the driving simulator study. It primarily investigated the effectiveness of the individual messages and how their presence affected driver behaviour towards more critical Tactical Incident Messages (TIM), such as those that might warn of an impending hazard. Both the content and concentration of the Safety Campaign Messages were varied. The Safety Campaign Messages in themselves were not especially beneficial, in that drivers did not significantly modify their driving style purely on the advice of the messages. However, witnessing the odd VMS carrying such a message appeared to improve driver alertness to the context of the VMS and consequently response to a TIM became more timely under these conditions. Yet, if the frequency of Safety Campaign Messages was overly high, drivers became jaded with the VMS content and their ability to act appropriately to a TIM degraded
A Cybernetic Perspective on Car Following in Fog
Get PDFDrivers often drive at a closer time headway (THW) in fog than in clear whether conditions for similar speed ranges (White & Jeffery, 1980). Closer following is generally considered more dangerous. The hypothesis pursued in this paper is that drivers experience a perceptual-motor benefit from driving closer in fog that results in greater (or equivalent) safety and reduced driving demand. A computational car following model with an experimentally constructed perceptual module is introduced and used to demonstrate that under some conditions, closer following in fog is indeed beneficial because it effectively reduces drivers’ perceptual delay by a sufficient amount to improve controllability of the gap so much that the variability in THW reduces more than (or as much as) the adopted decrease in target THW
Comparing the Influence of Two User Interfaces for Mobile Radios on Driving Performance
Get PDFMobile radios have a manufacturer-provided manual user interface that allows changing radio channels using buttons. There is also a display on the faceplate of the radio that is used to visually verify channel selection. The objective of this study was to compare the influence of the manual user interface and the Project54 speech user interface (SUI) on drivers’ performance while interacting with a mobile radio. In experiments conducted with a driving simulator we found that operating the manual user interface degraded driving performance significantly, while using the SUI did not
Long-Term Effects of More Punitive Legislation Concerning the Use of Mobile Phone During Driving in Portugal
Get PDFThe purpose of this study was to determine whether a change in legislation regarding the use of handheld cell phones in Portugal provoked a substantial reduction of their use and if one year latter this reduction was still visible. Drivers’ handheld cell phone use was observed prior to the implementation of more punitive legislation, immediately after, 6 months and one year after the change in legislation. Estimated age (+ or – 40 years old) and gender was also registered for cellular telephones users. The counts were taken over 20 one-hour occasions equally divided over the four periods of observation and they were performed at the IC19 near Queluz, which is one of the roads with the most intense traffic flows of the region, for a total of 66841 observations. Results showed a considerable reduction from 1.29% of drivers before the law to 0.67% immediately after. However, one year later, the results (1.27%) were analogous to the initial observations. Phone users were predominantly male (75.35%), but this percentage is equivalent to all road users, so a gender trend was not found. On the contrary, we found a higher trend of younger drivers using mobile phones while driving. One of the most probable reasons for the main effect found was that as time goes by, drivers realize the low risk of being charged and punished for phone use while driving. The more punitive measures implemented with the new law regarding phone use showed no long-term effects
Off-Road and On-Road Driving Assessments Methods, What Do They Say? A Clinical Sample
Get PDFDriving assessments are carried out in various ways, and diverse methods and tests are used. The British Stroke Driver Screening Assessment (SDSA) is a cognitive test, developed to evaluate driving fitness in stroke patients. For Sweden, Denmark and Norway, there is a Nordic version, the Nordic Stroke Driver Screening Assessment (NorSDSA). This cognitive test has become commonly used by driving assessors and is sometimes the only test used to evaluate driving fitness regardless of a client’s diagnoses. The objective of the study was thus to compare the off-road NorSDSA test outcome, expressed as a global pass or fail result, with an on-road driving test outcome. The results showed that 52 out of 63 patients were correctly classified in the drivers-fail group and 24 of 57 in the pass group. In total, 63% were correctly classified, (sensitivity 42% and specificity 83%). The NorSDSA is thus not a valid predictor for pass or fail on the on-road test. However, only a few neuropsychological tests are made for driving assessments. The NorSDSA is one of them, but driving assessors should know its apparent limitations. The recommendation is thus not to solely rely on the NorSDSA to assess fitness to drive
The Danger of Incorrect Expectations In Driving: The Failure to Respond
Get PDFThis paper addresses Inattentional Blindness or look-but-fail-to-see in driving. How it is possible that visual information, highly relevant for driving is not perceived or responded to. Our main focus was on driver expectations. Different experimental studies were performed. In the conducted studies, we had drivers perform a driving task in which they had to drive a specific road numerous times. This way they were able to control driver expectations with a specific road environment. After some drives we made some crucial changes to the road environment (e.g., change in priority, change in No-Entry road). Behavioural responses (speed, deceleration) were measured to these changes, as well as eye movenents (glance duration) and awareness of the changes. All partcipants were experienced drivers, and over all studies, 250 drivers participated. There was a relation between driver expectations and the failure to respond. Glance duration to traffic signs was found to decrease with a driver becoming more and more familiar with a specific road. Visually selecting the information seems to be an important condition for enabling a response, but it is certainly not enough. There are various cases where expectations were so strong that drivers looked at the information but did not respond. There seems to be a high correlation between glance duration and responding, as well as between the type of change and responding. In-vehicle equipment warning the driver for these types of situations is highly effective. An elaborated task performance model is presented
Change Blindness, Attention, and Driving Performance
No full textConcern over older driver high traffic fatality rates has resulted in an effort to identify risk factors and to develop methods of assessment. This study examines two attention-related tasks, Useful Field of View (UFOV) and Change Blindness (CB), in relation to vision and cognitive test batteries and driving performance measures collected using a simulator and an instrumented vehicle. Eight older adults with Alzheimer’s disease and nine comparison subjects between 64 and 81 participated. Factor analysis results indicate that UFOV and CB relate to different factors. While UFOV relates to memory, decision-making, attention, and visual spatial ability, CB relates to vision and attention. The type of images used on a CB task influence how the task relates to driving performance measures. Researchers should be thoughtful when selecting images to include in CB tasks to maximize insight into real-world drivin
Effects of Secondary Task Demands on Drivers’ Responses to Events During Driving: Surrogate Methods and Issues
Get PDFOBJECTIVES (1) To examine effects of secondary task demands on event detection and response during driving. (2) To examine the validity of surrogate methods which might be used in a laboratory environment to evaluate these effects early in the development process for advanced information systems. (3) To identify issues which limit and/or require careful interpretation in the application of event detection results to product considerations. (4) To identify issues which are at the forefront of scientific knowledge in this area, and in need of further research. METHODS Analytic methods were used to compare data derived from prior studies—and/or to make comparisons across studies. Linear mixed models, correlation, and other statistical methods were used, as appropriate. Results were drawn from several sources, and hence reflected multiple methodologies. One of the main sources of data for this work was the CAMP Driver Workload Metrics project (2006) (which was a collaborative project between GM, Ford, Toyota, Nissan, and USDOT). Three types of methods were compared: on-road, test track, and laboratory methods. In the onroad and test-track methods, 108 participants and 69 participants (respectively) drove an instrumented vehicle that was the middle car in a platoon of three vehicles. (That is, the test participants followed a lead vehicle—and also had a vehicle following them). Drivers engaged in 22 different secondary tasks while driving on public roads (or a test track), and while also responding to three different types of visual events that could potentially occur during a task. These event types included: the illumination of a CHMSL-like light on the lead vehicle, a deceleration of the lead vehicle (without brake lights), and a turn signal illumination on the follow-vehicle. In the laboratory, methods included a specially-developed variation of the Sternberg task, and two Peripheral Detection Tasks. Data were collected from 57 participants. Data from these methods are reported, compared with each other, and compared with data from other sources, where methods permitted that. Dependent variables were primarily “percent missed events”; key independent variables included task type and workload level. RESULTS Data showed that visual-manual and auditory-vocal tasks differed in their effects on event detection during driving, with visual-manual tasks (as a class) interfering to a greater extent with event detection. The effects of task demands on event detection could not, however, be fully accounted for by glance-related measurements, suggesting that there are other variables involved, such as an attentional component to event detection. Furthermore, the modifiedSternberg method emerged as a laboratory surrogate with promising predictive validity (as well as repeatability) for evaluating a task’s effects on event detection/response during driving. However, several issues emerged related to how the results of this assessment method can be interpreted and applied. These issues relate to practical matters (of task length, and task type), and also to theoretical matters (e.g., regarding how to change task design to mitigate interference with event detection). CONCLUSIONS Drivers’ responses to events while driving (particularly unexpected events) are an important element of driving performance. Early in the development of advanced information systems, it would be desirable to have a valid way to evaluate how task demands may affect event detection (so that system task designs could be modified and improved, if necessary). However, it is particularly difficult to study event detection experimentally. Nearly all existing methods of evaluating event detection and response (other than naturalistic driving studies) must be classified as surrogate methods. And most of the methods examined here used techniques that did not really qualify as presenting “completely unexpected” events. Nonetheless, with this caveat, the method which offered the most promise was that which was sensitive both to a task’s loading on visual processing and also its effects on central attention (e.g., to a cognitive/memory load). That method was the modified-Sternberg method. Issues related to interpretation and application suggested that discriminating high from low workload tasks may be a problem when Task Types are separated. However, conclusions about grouping Task Types together are offered. Further, the findings had implications for strategies that might be used during system development to improve event detection performance for a task. Additional research is needed, not only to verify the kinds of strategies for task development that would in fact lead to improved event detection performance, but also to examine issues surrounding development of methods for presenting unexpected events, and to establish a deeper understanding of processes that underlie event detection and response, especially in naturalistic driving REFERENCES Angell, L. S., Auflick, L. L., Austria, P. A., Kochhar, D. S. & Tijerina, L. (2006). “Driver workload metrics project: Task 2 final report,” submitted to U.S. Dept. of Transportation, FHA, & NHTSA under Cooperative Agreement Number DTFH61-01-X-00014
R We Fooling Ourselves: Does the Occlusion Technique Shortchange R Estimates?
No full textThe occlusion technique was originally used to evaluate the cognitive demands of the roadway. Recently, the occlusion technique has been used as a cost-effective tool for assessing the visual demand of in-vehicle devices. Occlusions simulate glances from an in-vehicle device to the roadway by interrupting visual sampling. However, occluding the in-vehicle device does not impose any additional cognitive demand on the participant like true glances back to the roadway. The purpose of this study was to compare standard no-task occlusions with occlusions requiring participants to perform a visual-motor tracking task. Results suggest that overestimates of resumability may result by not including a task during occlusions. Furthermore, estimations of visual demand based on individual post-occlusion resumption times may provide a more precise measure of transition costs and resumability than measures based on Total Shutter Open Time
Simulator-Based Learning: Achieving Performance Improvement Independent of Instructors
No full textThe Utah Department of Public Safety (UDPS) implemented a new driver training methodology in 2005, which they have used to train over 950 lawenforcement personnel over the past two years (2005–2006). The new methodology uses driving simulators for whole task practice and for measuring driver-performance. It places simulator-based practice between initial classroom instruction and test-track driver training. Prior analyses of the data collected for 355 drivers in the first year demonstrated that UDPS had successfully achieved: (1) objective measures of driver performance to establish pass/fail criteria, (2) effective motivation for drivers to improve their own performance, and (3) measures of the overall effectiveness of the training process. Summary reports of the first year of data collected at UDPS demonstrated: (1) SAS mitigation levels below the occurrence of test-track discomfort, and (2) a 67% reduction in risk for collisions by reduction of critical errors. The above success led to expanding the training to 598 new trainees in the second year. This paper reviews new driver performance data collected during 2006. Two additional trainers participated in that process. Analysis of this new data not only confirms the first year’s analysis, but newly establishes that: (1) improvement in driver performance is independent of the trainer(s), and (2) training benefit is a function of the sequence and number of exercises