00647270

Component

http://onlinepubs.trb.org...trr/1993/1421/1421-010.pdf

https://scholar.google.co...cCoy&publication_year=1993

The design of the traffic detection scheme at an intersection can have a considerable impact on traffic safety and efficiency. A detector design (i.e., the detector layout and controller timing) that is not "tuned" to the geometrics of the intersection and its traffic demands can result in higher motorist delays than would be obtained with pretimed control. The detector design can also have an effect on safety. Designs that continually present the yellow signal to drivers when they are in the zone of indecision are likely to be associated with more accidents than designs that detect these drivers and extend the green signal for them until they are clear of the intersection. The safety and efficiency of a traffic detector design can be determined from the probability of max-out [a max-out occurs when the green is extended by a continuous stream of arrivals until the maximum green duration is reached (and a conflicting call is continuously held on one or more phases)] and the amount of time spent waiting for gap-out and subsequent phase change. A detector design that minimizes these measures of effectiveness should provide safe and efficient operation. Achieving the optimal combination of these measures can be difficult because of complex interactions among detector design elements (i.e., detector location, detector length, vehicle speed, passage time setting, and call-extension setting). The methodology described in this paper will allow the designer to determine the optimal combination of design elements in terms of safety (via infrequent max-out) and operations (via a short waiting time for phase change).

This paper appears in Transportation Research Record No. 1421, Traffic Control Devices, Visibility, and Traffic Signal Systems. 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

01398730

English

p. 76-81

1993

Transportation Research Record

0309055741

Figures (3) ; References (2)

Geometric design; Intersections; Layout; Traffic safety; Vehicle detectors; Waiting time

Timing

Highways; Operations and Traffic Management; I73: Traffic Control

TRIS, TRB

May 2 1994 12:00AM

• ANALYSIS OF FLASHING SIGNAL OPERATION
• DECISION SUPPORT SYSTEM FOR CONTROLLING TRAFFIC SIGNALS
• DEVELOPMENT OF AN EMERGENCY ZONE SIGN
• ENHANCEMENTS TO THE PASSER II-90 DELAY ESTIMATION PROCEDURES
• ENTRANCE ANGLE REQUIREMENTS FOR RETROREFLECTORIZED TRAFFIC SIGNS
• EVALUATION OF THE FEDERAL VISION STANDARD FOR COMMERCIAL MOTOR VEHICLE OPERATORS
• EXACT ROAD GEOMETRY OUTPUT PROGRAM FOR RETROREFLECTIVE ROAD SIGN PERFORMANCE
• HYBRID GENETIC ALGORITHM TO OPTIMIZE SIGNAL PHASING AND TIMING
• MICROSCOPIC SIMULATION MODELING OF MINIMUM THRESHOLDS WARRANTING INTERSECTION SIGNALIZATION
• OPERATIONAL COMPARISON OF LEADING AND LAGGING LEFT TURNS
• PASSER IV: A PROGRAM FOR OPTIMIZING SIGNAL TIMING IN GRID NETWORKS (WITH DISCUSSION AND CLOSURE)
• SELECTION CRITERIA FOR LEFT-TURN PHASING AND INDICATION SEQUENCE