ADAMS' FORMULA REVISED
The author presents a revised form of Adams' formula for determining the expected delay to a pedestrian wishing to cross a traffic stream. The original formula uses the Poisson process as a statistical model for the traffic stream. Real traffic streams, however, have a tendency to form bunches with gaps between the bunches and these features are not modelled by the Poisson process. The derivation of the new average delay formula is given in an appendix. Representative curves relating average delay and traffic flow rate are shown for different distributions of bunches and bunch size. They demonstrate that average delay is sensitive to the bunch gap structure of traffic. Importantly, the new results are sufficiently different from those given by Adams' original formula that a revision of practical traffic warrents involving pedestrian facilities seems desirable. (TRRL)
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Availability:
- Find a library where document is available. Order URL: http://worldcat.org/issn/00410683
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Corporate Authors:
Printerhall Limited
29 Newmart Street
London W1P 3PE, England -
Authors:
- Cowan, R J
- Publication Date: 1984-5
Media Info
- Features: References; Tables;
- Pagination: p. 272-274
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Serial:
- Traffic Engineering & Control
- Volume: 25
- Issue Number: 5
- Publisher: Hemming Group, Limited
- ISSN: 0041-0683
- Serial URL: http://www.tecmagazine.com/
Subject/Index Terms
- TRT Terms: Bunching; Decision making; Mathematical models; Pedestrian flow; Pedestrian movement; Pedestrians; Poisson distributions; Traffic delays; Traffic flow; Vehicle spacing; Waiting time
- Old TRIS Terms: Bunching (Vehicles); Poissons distribution
- ITRD Terms: 652: Bunching; 1667: Crossing the road; 2248: Decision process; 9010: Delay; 6473: Mathematical model; 1733: Pedestrian; 671: Traffic flow; 694: Vehicle spacing; 9100: Waiting time
- Subject Areas: Highways; Operations and Traffic Management; Pedestrians and Bicyclists; I71: Traffic Theory;
Filing Info
- Accession Number: 00393261
- Record Type: Publication
- Source Agency: Transport Research Laboratory
- Report/Paper Numbers: HS-037 221
- Files: ITRD, TRIS, ATRI
- Created Date: May 31 1985 12:00AM