Abstract
An automated procedure for analyzing cumulative flow and speed curves is described. The essential features of this method are a routine that uses a piecewise linear approximation to identify times that speed or flow changes and a set of rules to identify periods of queue discharge flow (QDF) and prequeue flow (PQF). These rules are based on speed thresholds, the duration of periods of low speed, the times congested flow is observed at different locations relative to the bottleneck, and (in the case of PQF) the regression slope of flow versus time. Results of the automated analysis are compared with those of a previous manual analysis of data from 21 bottlenecks. The automated analysis identified more, but shorter, periods of QDF than did the manual analysis, primarily because it was more likely to identify very short periods of QDF or recovery from congestion, but fewer and longer periods of PQF. Average flow for automatically identified periods of QDF was similar to that of manually identified periods, but average flow for automatically identified periods of PQF was almost always lower than that for those identified manually.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
More From: Transportation Research Record: Journal of the Transportation Research Board
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.