729 research outputs found
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Influence of Headlight Design on Sensory Conspicuity of Powered Two-Wheelers
No full textConspicuity of Powered Two Wheelers (PTW) according to their frontal headlight design was evaluated in a car Daytime Running Light (DRL) environment. Three innovative headlight arrangements were studied: a triangle configuration, a lighted helmet and a colored frontal headlight. It was found that the helmet and the colored configuration led to better PTW detection performances than the standard configuration (a unique white headlight), especially when the PTW was far away. The triangle configuration did not prove to be effective. The theoretical and practical implications of these results are discussed
Revisiting Driver Behavior at Unsignalized Intersections: Time of Day Implications for Two-Way Left Turn Lanes (TWLTL)
No full textA novel procedure was developed and validated for the accurate observation of naturalistic driver gap acceptance behavior at unsignalized intersections. Specifically, two-way stop-controlled intersections with a two way left turn lane (TWLTL) on the major road were examined. Three intersections were included as experimental locations. A sample size was collected of approximately 875 minor street vehicles which were exposed to over 2400 individual gaps. Characteristics such as gender, approximate age, vehicle type, presence of a queue behind the lead vehicle, and presence of passengers in the vehicle were collected as a function of the time of day (TOD). This work provides updated measures for the accepted gap as TOD varies, as well as exploring how accepted gaps are related to the wait time of a vehicle at the stop line
The Impact of Distraction on an Intersection Crossing Assist System
No full textThe current study examines the impact of drivers’ use of an in-vehicle intersection crossing assist system under demanding cognitive load conditions. The use and adherence to the assist system is examined through intersection crossing driving performance measures. Furthermore, the impact of distraction is examined for younger and older drivers. The results suggest a more conservative approach to the crossing of rural intersections when using the assist system, a finding which was not altered by cognitive load
A Schema of Possible Negative Effects of Advanced Driver Assistant Systems
No full textThe purpose of Advanced Driver Assistance Systems (ADAS) is to enhance traffic safety and efficiency. ADAS can be considered as a (still incomplete) collection of systems and subsystems towards a fully automated highway system, such as autonomous cars. However, as many researchers argue, in assessing the benefits of ADAS it has to be taken into account that any gains in terms of security may be again reduced by the fact they affect the drivers' behavior. In this paper, we introduce a schema of possible negative effects of advanced driver assistant systems according to which consequences of a system failure largely depend on the magnitude of over-reliance. Based on that schema, we itemize hypotheses on possible behavioral effects of a specific ADAS type, namely local danger alerts
Driving with Para-Central Visual Field Loss: Pilot Study
No full textWe studied how para-central visual field loss affects pedestrian detection in a driving simulator. Participants with para-central field loss had relatively good visual acuity (20/15 – 20/60) and 3 of 5 met local vision requirements for an unrestricted drivers license; however, they had lower detection rates and longer reaction times to pedestrians likely to appear within the blind area than in their seeing areas. They were at collision risk for 7% to 30% of pedestrians, whereas controls were at a collision risk for 0 to 4% of pedestrians
Effects of Scheduling on Sleep and Performance in Commercial Motorcoach Operations
No full textMaintaining cognitive alertness during commercial motorcoach operations is important for drivers as they are responsible for preventing, detecting, and managing errors. Schedules that do not follow circadian and homeostatic sleep principles may contribute to fatigue related events and accidents. The Federal Motor Carrier Safety Administration (FMCSA) has hoursof-service (HOS) regulations in place that allow motorcoach operators to work backwardly rotating 18-23 hour duty cycles (a duty cycle being the sum of HOS mandated on and off duty periods), requiring progressively earlier start times. Such schedules do not allow for sufficient and appropriately placed rest periods, resulting in fatigue and decreased performance. This study will investigate the effect of scheduling on sleep and performance in motorcoach operators. We are collecting objective and subjective data on sleep and performance of motorcoach drivers working under the current HOS regulations to observe the prevalence of circadian friendly and mismatched schedules, and the impact work schedules have on sleep and performance. This article describes the study design and methodology
Exploring Factors that Influence Vehicle Purchase Decisions of Older Drivers: Where Does Safety Fit?
No full textVehicle design features that enhance safety can mitigate older driver frailty and declines in ability. We have investigated the older driver’s perception of vehicle safety and how this influences their vehicle purchase. Focus groups (n = 27) were conducted among drivers aged 70-90 in South-Western Ontario. Questions focused on participants’ perceptions of vehicle safety and design, the vehicle purchasing process, and resources used therein. Participants emphasized the importance of a few standard safety features (e.g., seatbelt, reliable brakes) but de-emphasized the role of safety on their purchase decisions. Safety was superseded by other purchasing considerations, most notably price. Stressful dealer-buyer interactions and poor congruency of information created barriers. Purchasing aids for older drivers should be developed that speak to the spectrum of safety technologies and emphasize the relationship between safety and other design features on driving ability
Microsleep Episodes and Related Crashes During Overnight Driving Simulations
No full textMicrosleep (MS) episodes and related crashes were studied in an overnight driving simulation study. A new definition of MS proposed recently was applied and the mean number as well as the mean length of MS was calculated. MS occurred much more frequently than crashes. Within all pre-crash intervals (length 1 minute) the percentage of MS was calculated. Results showed that there are numerous MS episodes before every crash. The mean length of MS was between 5 and 9 seconds and did not change significantly during the night. The mean MS percentage was high within pre-crash intervals (60-80%) and is a predictor for crashes
Serialization of Vehicle Control at Intersections in Older Drivers
No full textNegotiating intersections is a complex driving task that is particularly difficult for older drivers. This task requires accurate coordination of multiple driving subtasks, placing high demands on perception, attention and motor control that are known to decline with age. We analyzed intersection negotiation behavior in an instrumented vehicle and found striking differences in how drivers of different ages synchronize speed and heading control when turning right. The older drivers performed most of their steering while standing still instead of while accelerating as younger drivers do. This shift from parallel to serial control is a compensatory solution that drivers employ in response to age related decline in perception, cognition, and motor control abilities. Serialization of turning at an intersection reduces attentional demands largely by eliminating the need to switch attention between different driving sub-tasks
Assessing Drivers’ Tailgating Behavior and the Effect of Advisory Signs in Mitigating Tailgating
No full textA human factors study was carried out to assess drivers' tailgating behavior and the effect of advisory signs in mitigating tailgating. Tailgating is a dangerous driving behavior and a leading cause of most rear-end crashes. Through a prior study, serious tailgating was identified on urban Rhode Island highways. It is critical to many urban traffic management authorities to understand tailgating and to explore means to mitigate drivers’ tailgating behavior, especially on urban highways with high-speed and high-volume traffic. Properly designed advisory signs could reduce tailgating and related motor crashes. To assess drivers' behavior with regards to tailgating, a questionnaire survey was developed and given to a number of subjects with daily highway driving experience. The survey is designed to identify causes of tailgating and drivers’ perceptions and engagements on tailgating behavior. Drivers' driving behaviors were further assessed through driving simulation under different traffic conditions. To help mitigate tailgating behavior, advisory signs and an educational video were developed. The effectiveness of these proposed countertailgating measures was assessed in the driving simulation. Subjects’ real driving behaviors were further studied in a follow-up field study. Study results found that the majority had an incorrect sense regarding safe following distance and were tailgating while driving on highways. Heavy traffic was identified as the top tailgating cause. The simulation results confirmed the tailgating phenomenon observed on urban Rhode Island highways. The proposed advisory signs were found effective in mitigating tailgating behavior