00227718

Component

http://onlinepubs.trb.org...rbbulletin/291/291-001.pdf

THE RESULTS OF A RESEARCH PROJECT ON FREEWAY RAMPS AND INTERCHANGES WHICH IS BEING CONDUCTED BY THE TEXAS TRANSPORTATION INSTITUTE IN COOPERATION WITH THE TEXAS HIGHWAY DEPARTMENT ARE PRESENTED. THE STUDY WAS DESIGNED TO OBTAIN TRAFFIC PERFORMANCE DATA WHICH WOULD HAVE USEFUL APPLICATION IN EVALUATING THE CAPACITY OF SIGNALIZED DIAMOND INTERCHANGES. LIBRARY RESEARCH AND EVALUATION OF EXISTING DESIGN REQUIREMENTS INDICATED A GREAT DEMAND AND NEED FOR THIS TYPE OF DATA. THE FIELD DATA WERE GATHERED THROUGH THE USE OF TIME-MOTION PICTURES WHICH FURNISHED A COMPLETE AND SIMULTANEOUS RECORD OF THE TRAFFIC OPERATIONS OCCURRING IN THE INTERSECTIONS THAT WERE STUDIED. THE OPERATIONAL CHARACTERISTICS OF OVER 4,000 VEHICLES WERE RECORDED ON 16-MM FILM AT TWO CONVENTIONAL TYPE DIAMOND INTERCHANGES ON THE GULF FREEWAY IN HOUSTON, TEXAS. THESE DATA WERE COLLECTED DURING THE PEAK PERIODS ON APPROACHES THAT WERE FULLY LOADED. THE RESEARCH WAS CONDUCTED TO INVESTIGATE THE FACTORS WHICH COULD BE USED IN DEVELOPING CRITERIA FOR EVALUATING THE CAPACITY OF THE VARIOUS MOVEMENTS ENCOUNTERED IN DIAMOND INTERCHANGE OPERATION. DATA ON VEHICLE STARTING DELAYS AND TIME-HEADWAYS AT BOTH INTERCHANGES WERE ACCURATELY MEASURED TO DEVELOP A BASIC APPROACH TO THE DETERMINATION OF LANE CAPACITY. SPECIAL EMPHASIS WAS PLACED ON DETERMINING THE CAPACITY OF A SINGLE-LANE TURNING MOVEMENT AND A TWO-LANE, OR TWO-ABREAST-TYPE TURNING MOVEMENT. THE ANALYSIS OF THE STUDY PRODUCED SOME SIGNIFICANT RESULTS AND PROVIDES THE DESIGNER WITH CURRENT OPERATIONAL CHARACTERISTICS OF VEHICLES AT SIGNALIZED DIAMOND INTERCHANGES. DESIGN PROCEDURES FOR DIAMOND INTERCHANGES, BASED ON LANE CAPACITY AND SIGNALIZATION REQUIREMENTS, WERE DEVELOPED AND ARE PRESENTED IN THIS REPORT. /AUTHOR/

No 291, pp 1-25, 23 FIG, 1 TAB, 5 REF. 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.

01410675

English

25p

1961

Highway Research Board Bulletin

40th Annual Meeting of the Highway Research Board

Digital/other

Design standards; Diamond interchanges; Field studies; Headways; Highway capacity; Highway operations; Operations; Operations research; Peak hour traffic; Performance; Single lane traffic; Time and motion studies; Traffic signals; Two lane highways; Vehicle characteristics

Field data

Administration and Management; Highways; Operations and Traffic Management

TRIS, TRB

Aug 15 2004 2:36AM

• A QUANTITATIVE EVALUATION OF TRAFFIC IN A COMPLEX FREEWAY NETWORK
• ACCIDENT AND OPERATING EXPERIENCE AT INTERCHANGES
• Application of computer simulation techniques to interchange design problems
• DEVELOPMENT OF AN AUTOMATIC TRAFFIC FLOW MONITOR AND CONTROL SYSTEM
• FREEWAY TRAFFIC ACCIDENT ANALYSIS AND SAFETY STUDY
• OPERATIONAL STUDY - SCHUYLKILL EXPRESSWAY