Browsing by Subject "Driver performance"

Now showing 1 - 4 of 4
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    Estimating the Crash Reduction and Vehicle Dynamics Effects of Flashing LED Stop Signs
    (Minnesota Department of Transportation, 2014-01) Davis, Gary A.; Hourdos, John; Xiong, Hui
    A flashing LED stop sign is essentially a normal octagonal stop sign with light emitted diodes (LED) on the stop sign’s corners. A hierarchical Bayes observational before/after study found an estimated reduction of about 41.5% in right-angle crashes, but with 95% confidence this reduction could be anywhere between 0% and 70.8%. In a field study, portable video equipment was used to record vehicle approaches at an intersection before and after installation of flashing LED stop signs. After installing the flashing stop signs, there was no change in the relative proportion of clear stops to clear non-stops when minor approach drivers did not face opposing traffic, but the relative proportion of clear stops increased for drivers who did encounter opposing traffic. Random samples of 60 minor approach vehicles were selected before and after installation of flashing LED stop signs and speeds for these vehicles when about 500 feet from the intersection, and average deceleration rates over the final 500 feet, were estimated using trajectory-based methods. Average approach speeds tended to be highest in June, somewhat lower in July, and lower yet in September and November, with September and November having roughly equal average speeds. The average deceleration rates showed a similar pattern.
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    Human Factors Issues In Traffic Signing
    (1994-08) Hancock, Peter A.
    This work reports results of an experimental program on human factors issues in traffic signing. The first task examines the problems associated with the programming of signs for evaluation of driver response in simulation. It is concluded that growing technical tools permit traffic engineers to test proposed signage, and avenues of implementation are given. The second task examines driver response in simulation to multiple real-world signs. It is concluded that while much effort is given to distinguishing the utility of individual signs, multiple signs in combination produce more complex decrements. Recommendations are made as to maximum sign density. The final task provides an assessment of signage in future IVHS driving environments. It points to the role of signage as one component of communication. A list of issues for future signage implementation is given for consideration as the Department moves to provide safe and efficient transport for the people of Minnesota into the 21st century.
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    Older Driver Support System Field Operational Test
    (Center for Transportation Studies, University of Minnesota, 2019-05) Libby, David A.; Morris, Nichole L.; Craig, Curtis M.
    Older drivers represent the highest injury and fatality rate per 100 million miles driven. The disproportionate fatality risk is linked to several known factors, ranging from failure to yield to cognitive and visual limitations to seatbelt use abstention to fragility. Through a series of focus groups, usability tests, and a controlled field test, a universally designed smartphone app (called RoadCoach) designed to reduce risky driving behaviors, such as speeding and hard braking, was previously found to have high usability among older drivers. The current research consisted of a field operational test of the app, which examined the baseline driving behavior (3 weeks) of 28 older drivers in Minnesota and Kansas, their driving behavior with RoadCoach feedback (6 weeks), and their driving behavior during a follow-up, no-feedback period (3 weeks). The results demonstrated marginal reductions in speeding behaviors while the app was functioning, but speed behaviors significantly increased after the feedback was discontinued compared to when it was active. Hard braking and stop sign violations were significantly reduced during feedback and post feedback. Finally, satisfaction and trust were high among users, with drivers reporting that the app helped improve their attention and focus on the task of driving.
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    Simulated driver performance, error, and acceptance study of a J-turn intersection with 3 levels of signage
    (2024-01-08) Morris, Nichole L; Schwieters, Katelyn R; Tian, Disi; Craig, Curtis M; nlmorris@umn.edu; Morris, Nichole L; University of Minnesota HumanFIRST Lab
    Thirty-six participants with limited previous experience and knowledge of J-turn intersections participated in a simulation study to examine their acceptance of J-turns and left turning navigational performance at three simulated J-turn intersections in counterbalanced order, each featuring one of three signage levels (minimum, intermediate, and full). Participants navigational path was visualized and scored for error occurrence by 3 raters/coders. Eleven different error types occurred and they were classified as minor, moderate, or major severity errors. Participants provided demographic information, crash history, and acceptance of J-turn intersections (across three scales) before and after driving through the simulated J-turn intersections. The data has been deidentified and is available to provide a better understanding of common errors from drivers who are experiencing J-turn intersections for the first time and the resultant influence that their error experiences have on their acceptance of the novel intersection design.