Optimizing detector placement for high speed isolated signalized intersections using vehicular delay as the criterion /
On high speed approaches to an isolated intersection,
| Main Author: | |
|---|---|
| Format: | Thesis Book |
| Language: | English |
| Published: |
[Place of publication not identified] :
[publisher not identified] ;
1994.
|
| Subjects: |
| Summary: | On high speed approaches to an isolated intersection, providing for dilemma zone protection may result in sluggish operation and this in turn results in higher delays. A tradeoff analysis of detector placement is therefore essential for optimization of dilemma zone protection and reducing delays. TEXAS Model (Version 3.2) was employed to determine optimal detector placement strategies for high speed isolated intersections. The TXDOT detector placements for speeds of 55 mph (90 Km/h), 45 mph (70 Km/h) and 35 mph (55 Km/h) were used as a basis to achieve the objective. Due to limitations of the TEXAS Model, the maximum number of detectors that could be employed were limited to 3 for through lanes per approach. Identical geometry was assumed on all four approaches to the intersection. Different detector placement methods were developed while taking into account the dilemma zone criteria for a particular approach speed. Detector layouts were developed for mean speeds as well as for 85th percentile speeds. Simulation was performed for each detector layout for a particular speed against approach volume ranging between 200 vph to 800 vph and optimal detector layouts were identified as those that resulted in the least vehicular delay. It was found that for low approach volumes (<400 vph/approach) detector layouts with the innermost detector closer to the stop bar resulted in lower delay; whereas for approach volumes between 600 vph to 800 'vph, detector layouts with the innermost detector between 80 ft (24 m) to 120 ft (36 m) resulted in lower delays. |
|---|---|
| Item Description: | Vita. "Major subject: Civil Engineering". |
| Physical Description: | ix, 99 leaves : illustrations ; 28 cm. |
| Bibliography: | Includes bibliographical references. |