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Activity Number:
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318
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Type:
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Contributed
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Date/Time:
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Tuesday, August 5, 2008 : 2:00 PM to 3:50 PM
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Sponsor:
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Section on Risk Analysis
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| Abstract - #302358 |
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Title:
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Addressing the Complexity of Speed Measurements at Intersections in Determining the Effectiveness of Speed-Reducing Treatments
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Author(s):
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Courtney Bokenkroger*+ and Karin M. Bauer
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Companies:
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Midwest Research Institute and Midwest Research Institute
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Address:
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425 Volker Blvd, Kansas City , MO, 64110,
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Keywords:
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transportation ; speed data ; ANOVA ; repeated measures ; before-after evaluation ; distributional assumptions
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Abstract:
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The complexity of a statistical evaluation of the effectiveness of speed reduction treatments at high-speed intersections begins with first being able to understand and determine how transportation safety engineers typically measure effectiveness and extends into the complexity of the data collected and the distributional assumptions. In a recent study, vehicle speeds were measured at multiple locations along an intersection approach both before and after installation of the treatment. The analysis of the effectiveness of the treatment at a site was conducted using ANOVA with repeated measures. In this article, we discuss the complexity of the data and the factors that could and could not be accounted for in the analysis as well as their possible effects on estimates of the treatment effectiveness.
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