SOME CONSIDERATIONS OF VEHICULAR DENSITY ON URBAN FREEWAYS

VEHICULAR DENSITY STUDIES WERE MADE ON THE GULF FREEWAY IN HOUSTON, TEXAS. CONGESTION IS A QUALITATIVE TERM USED IN TRAFFIC ENGINEERING TO INDICATE A CONDITION OF TRAFFIC AND TRAFFIC MOVEMENT. DENSITY IS THE QUANTITATIVE MEASURE OF CONGESTION AND IS, THEREFORE, THE MOST DESIRABLE ELEMENT TO USE IN FREEWAY OPERATION CONTROL. THE PRINCIPAL FEATURES OF EXISTING METHODS USED TO MEASURE OR ESTIMATE DENSITY ARE REVIEWED. A PROCESS IN WHICH DENSITY IS ESTIMATED ON THE BASIS OF SPEEDS AND VOLUMES SENSED AT A POINT IS COMPARED TO A METHOD INVOLVING THE ACTUAL MEASUREMENT OF THE DENSITY, OR CONCENTRATION OF VEHICLES IN A SPACE. AERIAL PHOTOGRAPHY STUDIES ARE PRESENTED TO SHOW HOW DENSITY MAY BE RELATED TO VOLUME AS WELL AS TO CERTAIN GEOMETRIC FEATURES OF THE FREEWAY FACILITY. A FIELD STUDY METHOD IS DESCRIBED WHICH YIELDS CONTINUOUS VALUES OF VEHICULAR CONCENTRATION ON CERTAIN SECTIONS OF A FREEWAY. THE ANALYSIS OF THE DATA DEMONSTRATES A MEANS OF ESTABLISHING OPTIMUM, OR CRITICAL, FREEWAY CONCENTRATION VALUES AND PROVIDES A MEANS OF IDENTIFYING CRITICAL, OR BOTTLENECK, SECTIONS AT A FREEWAY WHICH EXHIBIT RECURRING HIGH DENSITIES.

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/hrr/1965/99/99-003.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:
  • Haynes, John J
• Publication Date: 1965

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: pp 59-80
• Monograph Title: Freeway characteristics, operations and accidents
• Serial:
  • Highway Research Record
  • Issue Number: 99
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Aerial photography; Concentration (Chemistry); Field studies; Freeways; Geometric design; Measurement; Methodology; Traffic congestion; Traffic control; Traffic density; Traffic speed; Traffic volume; Urban areas; Vehicles
• Identifier Terms: Gulf Freeway
• Uncontrolled Terms: Concentration
• Geographic Terms: Houston (Texas)
• Old TRIS Terms: Concentration index
• Subject Areas: Highways; Operations and Traffic Management; Vehicles and Equipment;

Filing Info

• Accession Number: 00224754
• Record Type: Publication
• Files: TRIS, TRB
• Created Date: Dec 12 1994 12:00AM