00621680

Component

http://onlinepubs.trb.org...trr/1991/1320/1320-005.pdf

https://scholar.google.co...+Poe&publication_year=1991

In the planning and design process, 24-hr volumes in the design year are converted to design hour volumes (DHVs) by using K factors ratio of 30th-highest-hour two-way volume to two-way average annual daily traffic (ADT) , D factors (directional split during the 30th-highest hour), and T factors (percentage heavy vehicles in the DHV). Lack of precision in selection of these parameters can make a plus or minus 50% difference in the design of urban freeways. The procedures used to select these factors in Texas urban areas have been examined, and refinements to the process are proposed. Using data from automatic traffic recorder (ATR) stations for 1973 to 1988 in the Texas cities of Houston, Dallas, Fort Worth, Austin, and San Antonio, along with manual classification data for 1984 to 1988, K, D, and T factors have been studied under increasingly urban conditions. Emphasis has been placed on the K and D factor research. Variables identified and tested for significance in predicting DHVs included facility type (radial or circumferential freeway), weekday ADT per lane, degree of capacity utilization during the peak period, employment density near the ATR station, length of peak period, and distance from the central business district. Although the initial data sets have yielded an unstable model over time using a multivariable regression analysis, ranges of K sub D (K factor by direction) for ranges of each variable are developed for use in determining reasonableness of preselected K and D values.

This paper appears in Transportation Research Record No. 1320, Freeway Operations, Highway Capacity, and Traffic Flow 1991. 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

01407170

p. 32-39

1991

Transportation Research Record

0309051533

Figures (13) ; Tables (2)

Average daily traffic; Beltways; Design hourly volume; Freeways; Radial highways; Urban areas

Texas

Texas

Highways; Operations and Traffic Management; I71: Traffic Theory

TRIS, TRB

Apr 30 1992 12:00AM

• ALINEA: A LOCAL FEEDBACK CONTROL LAW FOR ON-RAMP METERING
• ASSESSMENT OF THE TRAFFIC EXPERIMENTAL AND ANALYSIS SIMULATION COMPUTER MODEL USING FIELD DATA
• BENEFITS OF CENTRAL COMPUTER CONTROL FOR DENVER RAMP-METERING SYSTEM
• CAPACITY AND DELAY CHARACTERISTICS OF TWO-WAY STOP-CONTROLLED INTERSECTIONS
• CHARACTERISTICS AND LEVEL-OF-SERVICE ESTIMATION OF TRAFFIC FLOW ON TWO-LANE RURAL ROADS IN FINLAND
• DELAY EFFECTS ON DRIVER GAP ACCEPTANCE CHARACTERISTICS AT TWO-WAY STOP-CONTROLLED INTERSECTIONS
• EMPIRICAL ANALYSIS OF CONGESTED TRAFFIC FLOW CHARACTERISTICS AND FREE SPEED AFFECTED BY GEOMETRIC FACTORS ON AN INTERCITY EXPRESSWAY
• ENHANCEMENT AND FIELD TESTING OF A DYNAMIC FREEWAY SIMULATION PROGRAM
• EVALUATION OF HIGH-VOLUME URBAN TEXAS FREEWAYS
• EXAMINATION OF THE SPEED-FLOW RELATIONSHIP AT THE CALDECOTT TUNNEL
• FLOW AND CAPACITY CHARACTERISTICS ON TWO-LANE RURAL HIGHWAYS
• FREEWAY CAPACITY DROP AND THE DEFINITION OF CAPACITY
• FREEWAY CONTROL USING A DYNAMIC TRAFFIC FLOW MODEL AND VEHICLE REIDENTIFICATION TECHNIQUES
• IMPROVED DATA SCREENING TECHNIQUES FOR FREEWAY TRAFFIC MANAGEMENT SYSTEMS
• INTEGRATED SYSTEM OF FREEWAY CORRIDOR SIMULATION MODELS
• LESS-THAN-TRUCKLOAD TRUCKING IN LOS ANGELES: CONGESTION RELIEF THROUGH TERMINAL SITING
• OPERATIONAL EVALUATION OF TRUCK RESTRICTIONS ON I-20 IN TEXAS
• PROCEDURE FOR VALIDATION OF MICROSCOPIC TRAFFIC FLOW SIMULATION MODELS
• PROPOSED ANALYTICAL TECHNIQUE FOR ESTIMATING CAPACITY AND LEVEL OF SERVICE OF MAJOR FREEWAY WEAVING SECTIONS
• REAL-TIME EXPERT SYSTEM APPROACH TO FREEWAY INCIDENT MANAGEMENT
• REAL-TIME KNOWLEDGE-BASED INTEGRATION OF FREEWAY SURVEILLANCE DATA
• SATURATION FLOW: DO WE SPEAK THE SAME LANGUAGE?
• SIMULATION OF CROWD BEHAVIOR AND MOVEMENT: FUNDAMENTAL RELATIONS AND APPLICATION
• SIMULATION OF TWO- AND FOUR-WAY STOP CONTROL
• THE TWO-CAPACITY PHENOMENON: SOME THEORETICAL ISSUES
• TOLL PLAZA CAPACITY AND LEVEL OF SERVICE
• TOWARD A NEW GERMAN GUIDELINE FOR CAPACITY OF UNSIGNALIZED INTERSECTIONS
• TRAFFIC OPERATION OF BICYCLE TRAFFIC
• TWO-CAPACITY PHENOMENON AT FREEWAY BOTTLENECKS: A BASIS FOR RAMP METERING?