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Citation |
Fruin JJ, Ketcham BT, Hecht P. Transp. Res. Rec. 1988; 1168: 39-44. |
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Copyright |
(Copyright © 1988, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing) |
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DOI |
unavailable |
PMID |
unavailable |
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Abstract |
Time-space analysis is a new method for evaluating pedestrian activity spaces. This technique has been used in the Highway Capacity Manual (HCM) to determine pedestrian levels of service in corners and crosswalks. Although the new method follows established pedestrian traffic relationships, it had not been validated as a measure of actual street conditions. Evaluation of the pedestrian traffic impacts through the use of the HCM is a part of New York City's environmental review process for new developments, motivating the City Planning Commission, with U.S. Department of Transportation support, to sponsor a time-lapse photography study to validate the HCM pedestrian analysis method. Based on the analysis of time-lapse photography of pedestrian traffic activity at four Manhattan central business district intersections, the HCM time-space analysis model was found to be a valid procedure for determining pedestrian levels of service in corners and crosswalks. However, the photographic observations of pedestrian activity, combined with a computer sensitivity analysis of HCM model input parameters, indicated the following changes would improve the accuracy of the method: (a) standing area in corners for those waiting to cross increased from the HCM value of 5 sq ft/person to 7 sq ft/person; (b) occupancy time in corners for those moving through the corner changed from a uniform 4 sec to a value determined by a linear regression equation based on sidewalk width; (c) start-up time or delay of 3 sec for pedestrians to begin crossing in the HCM model eliminated to simplify the analysis model; and (d) walking speeds of pedestrians in crosswalks reduced from 4.5 ft/sec to 3.3 ft/sec as more representative of observed crosswalk platoon flow. An additional observation of the study was that although pedestrian levels of service show relatively little degradation because of turning vehicles, heavy pedestrian traffic noticeably reduced intersection capacity, potentially warranting turn restrictions where there are high crossing-volumes to increase intersection capacity, with secondary benefits of improved pedestrian safety and convenience. Language: en |
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Keywords |
Roads and Streets--Intersections; Street Traffic Control; Photography--Applications; Urban Planning--New York, NY |