A MOVING VEHICLE MERGING CONTROL SYSTEM
THREE RESEARCH PROJECTS WERE CONDUCTED TO DESIGN A SYSTEM OF OPTIMAL FREEWAY CONTROL. THE PROJECTS STUDIED THE JOHN LODGE FREEWAY IN DETROIT, THE EISENHOWER EXPRESSWAY IN CHICAGO, AND THE GULF FREEWAY IN HOUSTON. EACH PROJECT HAS MET WITH SOME SUCCESS, ALTHOUGH EACH HAS DEVELOPED A DIFFERENT CONTROL STRATEGY. THE ONE COMMON STRATEGY IS THE CONCEPT THAT, IN ORDER TO RELIEVE FREEWAY CONGESTION, THE RATE OF ENTRY OF VEHICLES FROM THE ENTRANCE RAMPS HAS TO BE CONTROLLED IN SOME MANNER. THE HOUSTON PROJECT IS THE ONLY ONE THAT ASSUMED A SECONDARY OBJECTIVE, APART FROM RELIEVING FREEWAY CONGESTION, OF AIDING THE RAMP DRIVER IN PERFORMING THE MERGING MANEUVER. THIS LED TO THE DEVELOPMENT OF THE GAP ACCEPTANCE METHOD OF CONTROL. A CONTROL SYSTEM DESIGNED TO FIT RAMP VEHICLES INTO FREEWAY GAPS HAS THREE BASIC REQUIREMENTS: (1) IT MUST BE ABLE TO MEASURE OR OTHERWISE DETERMINE THE ESTIMATED TIME-SPACE TRAJECTORY OF A RAMP VEHICLE, (2) IT MUST BE ABLE TO MEASURE AND ESTIMATE THE TIME-SPACE TRAJECTORY OF A FREEWAY GAP, AND (3) IT MUST BE CAPABLE OF CONTROLLING OR AFFECTING IN A KNOWN MANNER AT LEAST ONE OF THE FIRST TWO CHARACTERISTICS. THE FEASIBILITY OF THE CONTROLLED MOVING MERGE WAS CONFIRMED BY TWO SERIES OF STUDIES. THE FIRST SERIES OF TESTS PLACED THE RAMP DRIVER IN A POSITION TO MERGE 70 PERCENT OF THE TIME. THE INSTRUMENTED CAR SERIES WAS SUCCESSFUL MORE THAN 50 PERCENT OF THE TIME. THESE TESTS DEMONSTRATED THAT THE CONTROLLED MOVING MERGE CAN BE ACCOMPLISHED SUCCESSFULLY AND SAFELY. THE FACTORS OF BACKSIGHT, DRIVER, FREEWAY SPEED, AND RAMP SIGNALS WERE DETERMINED TO BE SUFFICIENTLY IMPORTANT TO WARRANT FURTHER RESEARCH. THE SECOND TEST SERIES INDICATES THAT STRESS-TIME CAN BE USED AS A FACTOR IN THE INDEXING OF DRIVER COMFORT. IF THIS APPROACH TO THE EVALUATION OF THE LEVEL OF SERVICE IS TO BE ACCEPTED, FURTHER RESEARCH IS REQUIRED. IT IS QUESTIONABLE AS TO THE AMOUNT OF DRIVER STRESS DESIRABLE. MINIMIZATION OF THIS STRESS MIGHT ENDANGER THE DRIVER BY REDUCING HIS LEVEL OF ALERTNESS.
- Record URL:
-
Supplemental Notes:
- Paper sponsored by Committee on Traffic Control Devices. 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
-
Authors:
- Buhr, J H
- Radke, M L
- Kirk, B M
- Drew, D R
- Publication Date: 1969
Media Info
- Media Type: Print
- Features: Figures; References; Tables;
- Pagination: pp 121-136
- Monograph Title: Freeway traffic characteristics and control
-
Serial:
- Highway Research Record
- Issue Number: 279
- Publisher: Highway Research Board
Subject/Index Terms
- TRT Terms: Drivers; Freeway operations; Gap acceptance; Interchange ramps; Level of service; Merging traffic; Motion; Motor vehicles; Reaction time; Traffic control
- Uncontrolled Terms: Driver reaction; Moving vehicles
- Old TRIS Terms: Freeway entrances and exits; Freeway ramps
- Subject Areas: Highways; Operations and Traffic Management;
Filing Info
- Accession Number: 00225541
- Record Type: Publication
- Report/Paper Numbers: Paper No 1
- Files: TRIS, TRB
- Created Date: Oct 21 1994 12:00AM