GAP AVAILABILITY STUDIES

GAP AVAILABILITY STUDIES WERE CONDUCTED TO ESTIMATE METERING RATES WHICH MIGHT BE USED IN THE AUTOMATIC RAMP METERING PROGRAM OF THE CHICAGO EXPRESSWAY SURVEILLANCE PROJECT. GAP AVAILABILITY /TIME HEADWAY/ DISTRIBUTIONS WERE COMBINED WITH GAP ACCEPTABILITY DISTRIBUTIONS FOR VARIOUS VOLUME AND LANE OCCUPANCY LEVELS TO ESTIMATE THE NUMBER OF ACCEPTABLE GAPS AVAILABLE UNDER DIFFERENT VOLUME AND LANE OCCUPANCY LEVELS. UNEXPECTEDLY, AN INCREASING NUMBER OF ACCEPTABLE AVAILABLE GAPS WAS FOUND AS THE SHOULDER LANE VOLUME AND OCCUPANCY LEVEL INCREASED. SIGNIFICANT DIFFERENCES WERE FOUND IN THE MEASURED TIME HEADWAY DISTRIBUTIONS BETWEEN LOCATIONS. THERE WAS A SIGNIFICANT DIFFERENCE BETWEEN EACH MEASURED TIME HEADWAY DISTRIBUTION AND THE POISSON DISTRIBUTION. THE POISSON DISTRIBUTION DOES NOT APPEAR TO SATISFACTORILY DESCRIBE TIME HEADWAY DISTRIBUTIONS FOR THE LOCATIONS AND TRAFFIC CONDITIONS STUDIED. THE ANALYSIS OF THE CUMULATIVE FREQUENCIES INDICATED THAT AS VOLUME LEVEL INCREASES, THE TIME HEADWAY BECOMES MORE UNIFORM. IT IS RECOMMENDED THAT A COMPREHENSIVE GAP ACCEPTANCE STUDY BE UNDERTAKEN, AND SUGGESTIONS TO BE CONSIDERED IN DESIGNING SUCH A STUDY ARE INCLUDED IN THE REPORT.

• Record URL:
  • http://onlinepubs.trb.org/Onlinepubs/hrr/1965/72/72-006.pdf
• Supplemental Notes:
  • 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:
  • May Jr, Adolf D
• Publication Date: 1965

Language

• English

Media Info

• Media Type: Print
• Features: Figures; References; Tables;
• Pagination: pp 101-136
• Monograph Title: Traffic flow characteristics 1963 and 1964
• Serial:
  • Highway Research Record
  • Issue Number: 72
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Freeway operations; Gap acceptance; Headways; Interchange ramps; Lane distribution; Mathematical analysis; Physical distribution; Rates; Traffic flow; Traffic surveys; Traffic volume
• Uncontrolled Terms: Traffic studies
• Old TRIS Terms: Freeway ramps; Metering
• Subject Areas: Freight Transportation; Highways; Operations and Traffic Management;

Filing Info

• Accession Number: 00226991
• Record Type: Publication
• Report/Paper Numbers: HS-006 579
• Files: TRIS, TRB
• Created Date: Aug 13 2004 6:55PM