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Dynamic Evaluation of the Useful Field of View in Driving
Get PDFThe concept of "useful field of view " (UFOV) was introduced to describe the area from which useful visual information can be extracted in a single glance. It is not restricted to the fovea, nor does it involve the entire visual field. It is often claimed that the UFOV decreases with age, with increasing speed of travel, or under the influence of drugs or stress. However, this potentially important tool for the evaluation of the role of human sensorial factors in road safety suffers from a lack of measurement techniques. Within this framework, we evaluated the ability of human observers to discriminate variations in their direction of heading from optical flow patterns simulating self-motion relative to a simple toric surface (a curved "tunnel"). We systematically evaluated perceptual performance as a function of the part of the global optical flow observers were looking at. Inasmuch as experimental laboratory data can be generalized to the complex task of driving, the results suggest that the perception of heading is optimal in a limited part of the visual field, situated around the future direction of travel. They offer a novel approach to the concept of useful field of view. They can be discussed in terms of their implications for road infrastructure design and for the positioning of warning and traffic signs within the driver's dynamic visual environment
Evaluating the Presence of In-Vehicle Devices on Driver Performance: Methodological Issues
Get PDFA central concern of Intelligent Transportation Systems (ITS) is the effect of in-vehicle devices (e.g. cell phones, navigation systems, radios) on driver performance and safety. As diverse and innovative technologies are designed and implemented for in-vehicle use, questions regarding the presence and use of these devices assume progressively greater importance. Concern for the safety of advanced driver training and require us to develop and validate reliable and effective procedures for assessing such effects. This work examines a number of candidate procedures, in particular the evaluation of cognitive workload as a strategy by which such goals might be achieved
A Simulator Study of Driver Response to Changeable Message Signs of Differing Length and Format
No full textHighway congestion nationwide continues to increase, and three Florida urban areas rank among the top ten. Congestion costs the State $3.5 billion annually in fuel and lost time, and is worsening because of: a) increasing population, b) projected travel increases, and c) recent legislation limiting additional highway capacity. Florida has been studying and implementing ITS technologies to address its congestion problems, with a focus on its special populations such as the elderly and multi-cultural groups for which English is not the primary language. One of these technologies most widely deployed is the changeable message sign (CMS). Fifty-two CMS are operational in Florida, with 39 more scheduled for deployment soon. Long-range plans will extend this technology Statewide. Although CMS have the potential to facilitate travel, certain issues must be considered to ensure that they do not exacerbate the congestion problem. Research has resulted in the development of guidelines which address message visibility, legibility and understandability. While these guidelines are helpful in informing the use of CMS, sign operation varies across jurisdictions, often without the basis of empirical support. Because successful CMS operation depends, in part, on driver information processing speed and linguistic ability, there is a need to evaluate CMS with Florida’s special populations. This study reports on an effort to determine the importance of specific CMS operational characteristics for drivers in general and elderly drivers in particular. One key CMS operational issue is the number of phases required to present a complete message. In one Florida jurisdiction about half of all CMS messages require one phase, and half require two. In another jurisdiction, fully 95 percent of CMS messages occupy two phases. There are also known cases of CMS using three-phase messages. “On-time” for two-phase messages varies from 2.5 to 5 seconds per phase across the State. Of course, the appropriateness of this on-time depends not only on the characteristics of the CMS itself (letter size, font, brightness, contrast, etc.), but on road, traffic and weather conditions, and, of course, on driver characteristics such as visual acuity, information processing speed, reading ability, and comprehension of English. This study, funded by the National Institute on Aging (NIA), investigated issues related to the number of CMS phases and their on-time. We used a low-cost, interactive driving simulator supplemented with a video monitor above the main display. While simulator screens presented interactive road and traffic conditions the supplemental monitor displayed the CMS. Young and old drivers drove the simulator under different workload conditions and responded to road closure/detour information on the CMS. All CMS displays were developed in accordance with accepted guidelines and were reviewed for content by independent experts. Results showed consistent and significant age effects across all tested conditions. In addition, we found significantly poorer response for all drivers under the two-phase CMS, despite the fact that our message “on-time” was nearly 2 seconds longer than that used in two major Florida jurisdictions. These findings have implications for CMS design and operation in Florida and in other jurisdictions with similar populations
Development of a National Licence Assessment Program for Older Drivers in Australasia
Get PDFLicensing requirements in Australasia vary across jurisdictions with little evidence of any safety benefit for any existing procedure. In 1998, Austroads (a collaboration of State Traffic Authorities in Australia and New Zealand) commissioned the Monash University Accident Research Centre to develop and trial a model licence re-assessment program for older drivers in Australasia. The procedure was developed in 1999 and involved input from a number of key experts in Australia and New Zealand. A pilot study was undertaken in Tasmania early in 2000 to evaluate the procedural aspects of the model. A study of four off-road screening tests also commenced in 2001 to validate these instruments against a range of driving performance measures. This paper reports preliminary findings from these studies
Measures of Driver Behavior and Cognitive Workload in a Driving Simulator and in a Real Traffic Environment - Experiences from Two Experimental Studies in Sweden
Get PDFThe use of ITS (Intelligent Transportation System) in general is increasing in road traffic with external demands on driver attention and cognitive functioning. Also in-vehicle systems such as navigation and onboard PCs with Internet and e-mail connections are on the market in many parts of the world. Two different studies are presented in this paper. These have focused upon mental performance as a result of driving in a tunnel simulation with a route choice task and in a real traffic environment with the effect of various in-vehicle navigation tasks. Results indicate future orientation and road choice problems, as much as 50% of test-drivers missed important road sign information and made critical road choice errors at specific points, i.e. entering the tunnel system from main roads. In the second study significant effects of visual and visual/verbal but no significant effects of verbal instructions on mental performance were obtained. These results are discussed with respect to requirements regarding suitable standard methods for assessment of cognitive workload caused by external information (i.e. road/tunnel environment) and from in-vehicle systems
Mental Workload and Task Performance for Indirect Vision Driving with Fixed Flat Panel Displays
Get PDFOf interest to designers of future combat vehicles is the effect of indirect vision upon vehicle driving, and in particular the effect of the camera lens field of view (FOV). In a field study, driving performance was measured for natural and indirect vision with eight participants negotiating a road course in a military vehicle. The indirect vision system was driven with fixed panoramic flat panel, liquid crystal displays in the cab and a forward viewing monocular camera array mounted on the front roof of the vehicle and tilted slightly downward. The results are that the participants successfully drove the vehicle with indirect vision for the different FOVs of the cameras: near unity, wide, and extended. However, they drove the course faster with natural vision than they did with the indirect vision systems. Further, the course speed significantly decreased with increased camera FOV. Workload ratings show a significant increase in perceived workload with increased FOV. Most participants reported a discomfort associated with motion sickness while they were in the moving vehicle with the displays. Finally, cluster analysis of the mental workload measures supports a skills-rules-knowledge model of information processing for the driving task
Using Microworlds to Design Intelligent Interfaces that Minimize Driver Distraction
Get PDFWhile recent developments in telematics have produced great interest in driverdistraction, this is hardly a new topic. An early UMTRI report (Treat, 1980)defined internal distraction as a diversion of attention from the driving task that iscompelled by an activity or event inside the vehicle. Based on data collected inMonroe County Indiana, Treat (1980) concluded that internal distraction was afactor in 9% of in-depth reports and 6% of on-site investigations. In the period ofdata collection (1972-1975) conversation with a passenger and increasing use ofentertainment tape decks were the major sources of distraction. Now a host ofmodern infotronic devices offers even greater opportunities for internal distraction(Kantowitz, 2000).Intelligent driver-vehicle interfaces present a wonderful opportunity tosuccessfully manage this increased in-vehicle workload. This smart interfacewould be adaptive, making dynamic allocation of function decisions in real time.Designing such an intelligent interface presents many problems. In particular,since new infotronic devices are being developed and deployed rapidly, it seemsdifficult to evaluate all these new designs. This chapter focuses upon usingmicroworlds to swiftly assess effects of in-vehicle infotronics upon driverdistraction.Microworlds vary along several dimensions such as realism, tractability andengagement (Ehret, Gray, & Kirschbaum, 2000). The traditional drivingsimulator is only one example of a relevant microworld. By considering a widerrange of microworlds, we can gain insight into how to best utilize drivingsimulators. Issues of validity are also illuminated when considered from amicroworld perspective. If appropriate intelligent interfaces are designed,telematics should never increase driver distraction
Virtual Truck Driver Training and Validation: Preliminary Results for Range and Skid Pad
Get PDFThis poster presentation will describe preliminary work done at the Carnegie Mellon Driver Training and Safety Institute (CM-DTSI) to test the validity of truck driver simulator training for backing maneuvers, and the digitalization of a skid pad. Preliminary results supported the validity of simulator training for straight-line and reverse-lane-change backing skills. Results for the skid pad work indicated that stopping distances during hard braking on the virtual skid pad were somewhat shorter than on the physical skid pad at the same initial speed. The shorter stopping distance in the simulator was the result of the functional limit of 0.2 surface coefficient of friction in the simulation dynamic model. A virtual skid pad with a slope of 9% was created to test the effect of slope on braking distance. Results showed that stopping distances in the simulator increased as a result of increasing the slope, indicating that the functional limit of the dynamic model can be overcome by varying the virtual slope
Examination of Older Driver Steering Adaptation on a High Performance Driving Simulator
Get PDFThe objective of this study was to examine how long it takes for older drivers to adapt their steering control on a fixed-base driving simulator. We hypothesized that older drivers achieve maximum training benefit within the first few minutes of a driving simulation. Thirteen drivers over 65 years of age drove a four-channel, 150º forward field-ofview, 50º rear field-of-view, fixed-base driving simulator for 25 minutes. We used a six-degree steering wheel reversal criterion to evaluate drivers’ adaptation to the simulator. Since drivers’ adapt to a simulator over time, we examined the number of steering wheel reversals greater than six degrees that occurred per minute during each of three sections, the start, middle and end of the 25-minute drive. The results showed that older drivers needed about three minutes to adapt and get the “feel” of the simulator. Before this time driving behavior in the simulator may not be representative of actual driving performance. These results provide preliminary support for assuming that an adaptation period as short as five minutes may enable drivers to adapt to the driving simulator and drive normally
Driver Behaviour Studies in the Motorway Operations Platform Grant
Get PDFThis paper will report on a four-year project being undertaken in the U.K., which intends to address the causative mechanisms of motorway congestion, and how these may be overcome by the use of in-vehicle Intelligent Transport Systems (ITS). The project comprises five studies, two focussing on driver behaviour and performance, and three on microscopic simulation and road operations. This paper will provide an overview of progress made and work in progress in the former of these topics, in particular: i) Phase 1: an instrumented vehicle study collecting microscopic time series on how drivers behave in slow moving dense traffic. An overview of results from this phase will be presented. ii) Phase 2: to be initiated in late 2001, looks to examine how drivers behave when faced with the requirement for an emergency deceleration. The study will use a combination of a surrogate vehicle/test track approach and a fixed base driving simulator study, in order to examine the advantages of the differing methodologies and (if validity is proven) to increase database size. A brief review will be given of the intended use of outputs from these studies in subsequent simulation modelling studies to be undertaken in future years