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Title: CALIBRATION OF TRANSIT NETWORKS IN MEDIUM-SIZED URBAN AREAS
Accession Number: 00227956
Record Type: Component
Abstract: THE FIRST STEP IN EFFECTIVE TRANSPORTATION PLANNING FOR URBAN TRANSIT FACILITIES IS TO TAKE INVENTORY AND CODE THE EXISTING FACILITIES AND THE CHARACTERISTICS OF TRAVEL ON THEM. NETWORK CALIBRATION IS THE PROCESS WHEREIN THE NETWORK SIMULATED FROM INVENTORY DATA IS REVISED BY A LOGICAL PROCEDURE SO THAT TRAVEL ROUTED OVER IT BY THE COMPUTER IS CHARACTERISTICALLY SIMULAR TO THAT OBSERVED ON THE ACTUAL NETWORK. NETWORK CALIBRATION IS IMPORTANT IN TRANSPORTATION PLANNING BECAUSE: (1) IT INSURES THAT THE EXISTING OPERATING CHARACTERISTICS OF EACH MODE ARE ACCURATELY DESCRIBED, (2) THE ESTIMATION OF FUTURE TRAVEL VIA EACH MODE CONSIDERS THE RELATIVE LEVEL OF SERVICE AFFORDED BY EACH MODE, WHICH IS CLOSELY RELATED TO NETWORK SPEEDS AND OPERATING CHARACTERISTICS, AND (3) OPERATIONAL PROBLEMS INVOLVING NETWORK COMPONENTS ARE MORE EASILY STUDIED WITHIN THE ADJACENT NETWORK STRUCTURE. A METHOD IS DOCUMENTED FOR PREPARING CALIBRATED TRANSIT NETWORKS, USING NETWORK INVENTORY DATA AND TRAVEL PATTERNS OBSERVED IN SEVERAL UPSTATE NEW YORK CITIES. VARIABLES CHOSEN TO REPRESENT THE CHARACTERISTICS OF THE NETWORK IN THE CALIBRATION PROCESS MEASURE ROUTE COVERAGE, FREQUENCY OF SERVICE, AND TRAVEL SPEED. THE INITIAL PHASE OF CALIBRATION INVOLVES THE MAIN LINE PORTION OF THE NETWORK. CHECKS ON BUS-MILES OF PORTION OF THE NETWORK IS CORRECTLY DESCRIBED. PATTERNS OF TRAVEL OVER THE NETWORK CAN BE ANALYZED FOR SIMILARITY WITH ACTUAL TRAVEL CHARACTERISTICS. THIS PHASE OF CALIBRATION IS CONCERNED WITH SIMULATING OPERATING CHARACTERISTICS BY REVISING THE NETWORK SO THAT THE DISTRIBUTIONS OF TRAVEL, TIME AND DISTANCE ARE SIMILAR TO INDEPENDENTLY DERIVED DISTRIBUTIONS. OTHER USEFUL CHARACTERISTICS ARE AVERAGE TRIP TIME AND LENGTH, PERSON-MILES OF TRAVEL, PERSON-HOURS OF TRAVEL, TRANSFERS, AND SCREEN LINE COUNTS. A TRANSIT NETWORK OF AVERAGE COMPLEXITY CAN BE CALIBRATED IN TWO OR THREE ASSIGNMENTS, GIVEN PREVIOUS AGREEMENT BETWEEN ACTUAL VEHICLE SPEEDS AND THOSE OSTED OR REPORTED BY THE OPERATING AGENCY.
Supplemental Notes: Paper sponsored by Committee on Origin and Destination. 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
Monograph Title: Monograph Accession #: 01410236
Authors: Hartgen, David TPagination: pp 44-56
Publication Date: 1969
Serial: Media Type: Print
Features: Figures
(8)
; Tables
(3)
TRT Terms: Old TRIS Terms: Subject Areas: Operations and Traffic Management; Transportation (General)
Files: TRIS, TRB
Created Date: Mar 9 1982 12:00AM
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