OVERFLOW DELAY ESTIMATION FOR A SIMPLE INTERSECTION WITH FULLY ACTUATED SIGNAL CONTROL
Queueing delay at a traffic signal can be generally estimated as the sum of two components, uniform delay and overflow delay. The delay formula in the 1985 Highway Capacity Manual (HCM) applies primarily to lane groups under pretimed control. Although the HCM contains a method for estimating cycle length and splits under vehicle-actuated operation, the resulting effect on delays has yet to be verified. Furthermore, the HCM assumption of "snappy" operation and its inability to compare pretimed and actuated control have been criticized in the literature. An approach for estimating overflow delays for lane groups under vehicle-actuated control using the current HCM delay model format is presented. An existing cycle-by-cycle simulation model has been modified to produce delay for a basic vehicle-actuated signal operation. Overflow delay is computed as the difference from total simulated delay minus estimated uniform delay for the average cycle conditions. The results indicate that the average cycle and overflow delays are very much related to the controller settings such as minimum and maximum greens and cycles and unit extensions, with longer unit extensions producing higher cycle length and overflow delay. Furthermore, applying the 1985 HCM formula to the simulated signal settings resulted in much higher delays, which implies the need for separate calibration of the second delay term to account for the actuated control effects. The simulation model was executed to produce a calibration data base for an analytical overflow delay model.
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Availability:
- Find a library where document is available. Order URL: http://worldcat.org/isbn/0309061008
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Supplemental Notes:
- This paper appears in Transportation Research Record No. 1457, Part 2, Traffic Flow and Capacity. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved
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Authors:
- Li, Jing
- Rouphail, Nagui M
- Akcelik, Rahmi
- Publication Date: 1994
Language
- English
Media Info
- Features: Figures; References; Tables;
- Pagination: p. 73-81
- Monograph Title: Part 1: 1994 TRB Distinguished Lecture, Adolf D May; Part 2: Traffic flow and capacity
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Serial:
- Transportation Research Record
- Issue Number: 1457
- Publisher: Transportation Research Board
- ISSN: 0361-1981
Subject/Index Terms
- TRT Terms: Estimating; Simulation; Traffic actuated controllers
- Identifier Terms: Highway Capacity Manual
- Old TRIS Terms: Overflow delay
- Subject Areas: Highways; Operations and Traffic Management; I71: Traffic Theory;
Filing Info
- Accession Number: 00677649
- Record Type: Publication
- ISBN: 0309061008
- Files: TRIS, TRB, ATRI
- Created Date: May 11 1995 12:00AM