ANALYSIS OF A SIGNAL-CONTROLLED RAMP'S CHARACTERISTICS
ALTHOUGH IT IS EVIDENT WHICH MEASUREMENTS DESCRIBE AN UNCONTROLLED RAMP OPERATION, MEASUREMENTS RELEVANT TO DESCRIBING THE OPERATION OF A SIGNAL-CONTROLLED RAMP ARE NOT READILY APPARENT. A BASIC QUEUING APPROACH IS UTILIZED TO DEVELOP A MODEL ATTEMPTING TO DESCRIBE THE OPERATION OF A SIGNAL-CONTROLLED RAMP. THE ASSUMPTIONS OF POISSON ARRIVALS INTO THE RAMP, A NEGLIGIBLE MOVE-UP TIME IN THE QUEUE, AND AN ERLANG DISTRIBUTION OF FREEWAY GAPS INHERENT IN THE MODEL ARE VERIFIED BY STUDY MEASUREMENTS. A RATE OF SERVICE (WAIT AT THE SIGNAL) IS THEN PREDICTED FOR BOTH FIXED-RATE METERING AND GAP-ACCEPTANCE CONTROL. THE AVERAGE QUEUE AT THE RAMP SIGNAL IS ALSO PREDICTED FOR BOTH TYPES OF SIGNAL CONTROL. THE PREDICTED VALUES ARE COMPARED TO OBSERVED STUDY DATA. THE STUDY WAS CONDUCTED ON THE DUMBLE STREET INBOUND ENTRANCE RAMP ON THE GULF FREEWAY (INTERSTATE 45), HOUSTON, IN 1968. BECAUSE THE COMPUTERIZED DATA COLLECTION SYSTEM WAS NOT FULLY OPERATIONAL AT THE TIME THE STUDY WAS CONDUCTED, A FIELD DATA COLLECTION SCHEME WAS DEVELOPED TO MONITOR IN-PLACE LOOP DETECTORS. /AUTHOR/
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Supplemental Notes:
- Paper sponsored by Committee on Characteristics of Traffic Flow and presented at the 49th Annual Meeting. 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:
- Brewer, Kenneth A
- Publication Date: 1970
Media Info
- Media Type: Digital/other
- Features: Figures; References; Tables;
- Pagination: pp 48-61
- Monograph Title: Traffic flow characteristics
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Serial:
- Highway Research Record
- Issue Number: 308
- Publisher: Highway Research Board
Subject/Index Terms
- TRT Terms: Gap acceptance; Interchange ramps; Mathematical models; On ramps; Poisson ratio; Queuing; Traffic control; Traffic signals
- Old TRIS Terms: Freeway ramps; Metering; Poissons ratio
- Subject Areas: Highways; Operations and Traffic Management;
Filing Info
- Accession Number: 00225833
- Record Type: Publication
- Files: TRIS, TRB
- Created Date: Oct 13 1970 12:00AM