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Transportation Research Record

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Signalized intersections -- Research -- Oregon -- Portland, Traffic flow -- Research -- Oregon -- Portland


This study analyzed motorist and bicyclist understanding and preference of positive confirmation of detection of a bicycle by the traffic signal infrastructure using a blue light detection confirmation (BLDC). The research analyzed results of an online survey of 1,123 respondents and intercept survey of 337 respondents. The study initially found that participants of the survey did not understand the meaning of the blue light itself, but comprehension of the system rose from 40% to 50% when supplemental signs were used. Respondents overwhelmingly indicated that they preferred the sign option that included symbols, text, and a representation of the blue light, in comparison with the sign options that only included symbol and text, or text and blue dot. Additionally, respondents indicated that they “strongly agree” that the supplemental signage helped with understanding the purpose of the detection confirmation devices, that they would support the system at intersections, and that it made them feel better about waiting at an intersection with light. Including supplemental signage with the symbol, text, and blue dot could potentially improve the riding experience for users, as it was strongly preferred among the alternative sign options that were tested; however, further evaluation of sign configurations may be warranted.


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This is the author’s version of a work that was accepted for publication in Transportation Research Record, Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Transportation Research Record, 0(0).



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