GAP-ACCEPTANCE CHARACTERISTICS IN FREEWAY TRAFFIC FLOW
AERIAL DATA WERE USED TO DETERMINE AVERAGE SPATIAL AND TIME SIZES OF THE ACCEPTED GAPS AND THE LAG GAPS IN GAP-ACCEPTANCE MANEUVERS FOR EXISTING VEHICLES CLOSE TO THEIR INTENDED OFF-RAMP AND FOR THROUGH VEHICLES AS A FUNCTION OF DISTANCE FROM THE OFF-RAMP. FURTHERMORE, AN ATTEMPT WAS MADE TO QUANTIFY THE ACCIDENT RISK THAT WAS ASSUMED BY EACH LANE CHANGER AND THE ACCIDENT RISK THAT WAS IMPOSED BY EACH LANE CHANGER ON THE LARGE CAR OF THE ACCEPTED GAP. RESULTS WERE OBTAINED FOR AN 8-, A 6-, AND A 4-LANE FREEWAY SITE AND FOR VARIOUS FLOW LEVELS. IN GENERAL, THE AVERAGE SPATIAL AND TIME GAP AND LAG GAP SIZES OF GAPS ACCEPTED BY EXITING VEHICLES DECREASE AS THE EXITING VEHICLES APPROACH THE OFF-RAMP. THE CORRESPONDING AVERAGE VALUES FOR THROUGH VEHICLES SHOW LESS, IF ANY, DEPENDENCY ON DISTANCE FROM THE OFF-RAMP. AVERAGE GAP AND LAG GAP SIZES OF GAPS ACCEPTED BY EXITING AND THROUGH VEHICLES DECREASE WITH INCREASING FLOW LEVELS. WITHIN THE ASSUMPTIONS MADE, IT WAS FOUND THAT A LARGER ACCIDENT RISK IS ACCEPTED BY EXITING VEHICLES THAN BY THROUGH VEHICLES IN THEIR LANE CHANGES, WHEREAS THE ACCIDENT RISK IMPOSED ON THE LAG CAR OF THE ACCEPTED GAP IS SMALLER FOR LANE CHANGES BY EXITING VEHICLE THAN BY THROUGH VEHICLE.
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Availability:
- Find a library where document is available. Order URL: http://worldcat.org/isbn/0309020816
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Supplemental Notes:
- Sponsored by Committee on Traffic Flow Theory and Characteristics. 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:
- Pahl, Juergen
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Conference:
- 51st Annual Meeting of the Highway Research Board
- Location: Washington District of Columbia, United States
- Date: 1972-1-17 to 1972-1-21
- Publication Date: 1972
Media Info
- Media Type: Digital/other
- Features: Figures; References; Tables;
- Pagination: pp 57-63
- Monograph Title: Traffic flow characteristics and models
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Serial:
- Highway Research Record
- Issue Number: 409
- Publisher: Highway Research Board
Subject/Index Terms
- TRT Terms: Freeway operations; Gap acceptance; Interchange ramps; Traffic crashes; Traffic lanes
- Uncontrolled Terms: Change
- Old TRIS Terms: Freeway entrances and exits
- Subject Areas: Highways; Operations and Traffic Management;
Filing Info
- Accession Number: 00226587
- Record Type: Publication
- ISBN: 0309020816
- Files: TRIS, TRB
- Created Date: May 15 1973 12:00AM