In-service Evaluation of a Detection-control System for High-speed Signalized Intersections PDF Download
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Author: Karl Zimmerman
Publisher:
ISBN:
Category : Electronic traffic controls
Languages : en
Pages : 52
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Book Description
Traffic engineers are often faced with operational and safety challenges at rural, high-speed signalized intersections. Vehicle-actuated control, combined with multiple advance detectors, is often used to improve operations and safety. However, this type of detection and control has not always resulted in a significant number of crashes. Crashes sometimes continue to occur at high-speed intersections, and delays to traffic movements can be unnecessarily long. An innovative detection-control system was developed for the Texas Department of Transportation to minimize both delay and crash frequency at rural intersections. This system was subsequently implemented at several intersections in Texas and its safety and operational benefits were evaluated. This report documents the findings and conclusions reached as a result of a three-year implementation project. The Detection-Control System was installed at each of eight intersections in Texas during the three-year period. Five of the intersections were suitable for a before-after study of safety and operational data. An evaluation of the before-after data indicated that the Detection-Control System was able to reduce delay by 14 percent, stop frequency by 9 percent, red-light violations by 58 percent, heavy-vehicle red-light violations by 80 percent, and severe crash frequency by 39 percent.
Author: Karl Zimmerman
Publisher:
ISBN:
Category : Electronic traffic controls
Languages : en
Pages : 52
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Book Description
Traffic engineers are often faced with operational and safety challenges at rural, high-speed signalized intersections. Vehicle-actuated control, combined with multiple advance detectors, is often used to improve operations and safety. However, this type of detection and control has not always resulted in a significant number of crashes. Crashes sometimes continue to occur at high-speed intersections, and delays to traffic movements can be unnecessarily long. An innovative detection-control system was developed for the Texas Department of Transportation to minimize both delay and crash frequency at rural intersections. This system was subsequently implemented at several intersections in Texas and its safety and operational benefits were evaluated. This report documents the findings and conclusions reached as a result of a three-year implementation project. The Detection-Control System was installed at each of eight intersections in Texas during the three-year period. Five of the intersections were suitable for a before-after study of safety and operational data. An evaluation of the before-after data indicated that the Detection-Control System was able to reduce delay by 14 percent, stop frequency by 9 percent, red-light violations by 58 percent, heavy-vehicle red-light violations by 80 percent, and severe crash frequency by 39 percent.
Author: Dan R. Middleton
Publisher:
ISBN:
Category : Detectors
Languages : en
Pages : 118
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Book Description
Author: Prahlad D. Pant
Publisher:
ISBN:
Category : Electronic traffic controls
Languages : en
Pages : 248
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Book Description
The effects of two dynamic signs that begin to flash a few seconds before the onset of the yellow interval and a static sign that flashes all the time were examined at tangent and curved approaches to rural, high speed signalized intersections. The dynamic signs included (a) a PTSWF (prepare to stop when flashing) sign, and (b) a FSSA (flashing symbolic signal ahead) sign with green, yellow, and red circles. The static sign was a CFSSA (continuously flashing symbolic signal ahead) sign with the three circles. The effects of these signs on vehicular speeds at different segments of the intersection approach including the dilemma zone were analyzed as were the vehicle conflict rates and the responses from the drivers' surveys.
Author: Karl H. Zimmerman
Publisher:
ISBN:
Category : Roads
Languages : en
Pages :
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Book Description
This Innovations Deserving Exploratory Analysis project improved and evaluated a detection-control system (D-CS) for enhanced traffic safety at high speed signalized intersections. A literature review was conducted to identify potential enhancements to the D-CS control algorithm required to create the "second generation" D-CS algorithm. The needed enhancements included dilemma zone protection based on vehicle size, real-time dilemma zone changes, coordination, and real-time measures of effectiveness reporting. After selecting the most feasible enhancements, the control algorithm was modified and tested in the laboratory. Based on laboratory test results and refinements, a "second generation" D-CS control algorithm was developed capable of providing dilemma zone protection specific to vehicle type using a modified system to prevent max out during "Stage 2" operation.
Author: James A. Bonneson
Publisher:
ISBN:
Category : Detectors
Languages : en
Pages : 94
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Book Description
Author: Peter T. Martin
Publisher:
ISBN:
Category : Electronic traffic controls
Languages : en
Pages : 64
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Author:
Publisher:
ISBN:
Category : Detectors
Languages : en
Pages : 102
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Book Description
Author: Jeromy L. Grenard
Publisher:
ISBN:
Category : Detectors
Languages : en
Pages : 230
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Book Description
Author:
Publisher:
ISBN:
Category : Detectors
Languages : en
Pages : 42
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Book Description
The primary objective of this research was to validate the new TxDOT procedures for loop detector placement on high-speed approaches to signalized intersections. The study approach involved conducting a field study at selected sites to compare the proposed new loop configuration to the existing configuration. The data analysis included investigating approach speeds to the intersection, driver actions in response to a yellow indication, and vehicle location at the onset of yellow. The Results from the field study revealed that the new loop configuration is as good as, and in some cases better than the old loop configuration. Because the new loop configuration can detect vehicles further upstream from the intersection (at the beginning of the dilemma zone), it results in fewer vehicles being caught in the dilemma zone at the onset of yellow. Also, because the new loop configuration typically resulted in more vehicles running the yellow light instead of stopping, fewer rear-end accidents may result. In addition, the new loop configuration resulted in fewer vehicles running the red light, also a major cause of accidents.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 108
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Book Description
