Accounting for non-random arrivals in the estimate of delay at signalized intersections /
Signalized arterials have been recognized as a critical part of the transportation supply 'in many urban areas. The effective utilization of these arterials rely-y upon signal timing plans that minimize the delay experienced by vehicles on these arterials. One characteristic of these signali...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1995.
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| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=742145071&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | Signalized arterials have been recognized as a critical part of the transportation supply 'in many urban areas. The effective utilization of these arterials rely-y upon signal timing plans that minimize the delay experienced by vehicles on these arterials. One characteristic of these signalized arterials is that the vehicles arrive in groups or platoons which affects the estimate of delay. Although procedures have been developed to account for the effects of progression on the estimate of delay, these procedures are limited 'in their ability to describe a broad range of platoon arrival conditions. The primary objective of this research was to determine the effect of nonrandom or platoon arrivals on the estimate of delay at signalized intersections. The parameter used to describe the arrival pattern is a variable k that is used 'in the steadystate delay model to describe stochastic delay. The 1985 Highway Capacity Manual (HCM) delay model uses a fixed value of 0.5 which is based on queueing theory and describes a queueing model with random arrivals and a fixed service time. Along an arterial where the upstream intersection meters the flow of vehicles to the downstream intersection, the arrivals are no longer random and the k value is 'in general much smaller than what is used at ail isolated intersection. This research provides an estimate of the k variable for arterial conditions using the time dependent formulation found in the HCM delay model to estimate the incremental delay. An analytical equation was developed in this research which 'provides an estimate for the k value. The equation is expressed as a function of the provides degree of saturation and a separate equation was developed for each signal controller type. The results from this research show that the proposed k variables provide delay estimates closer to the measured delay when compared to delay estimates using a fixed k value of 0.5 The study also developed alternative factors to account for the early/late arrival of the platoon at the intersection. These fp factors were developed for the 1994 HCM delay model and a separate factor is provided for each arrival type and a broad range of platoon arrival conditions. |
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| Item Description: | Vita. "Major Subject: Civil Engineering". |
| Physical Description: | xii, 134 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references. |