Showing papers on "Traffic count published in 1973"

Analysis of urban area travel by time of day

Abstract: THIS RESEARCH PROJECT IS A THOROUGH ANALYSIS OF THE TEMPORAL DISTRIBUTION OF VEHICULAR TRAVEL IN EIGHT U.S. URBAN AREAS HAVING POPULATIONS OF 100,000 TO 3,500,000. GRAPHICAL MODELS WERE DEVELOPED DURING THE ANALYSIS, AND TRAVEL DATA FROM ST. LOUIS ARE PRESENTED IN DETAIL ALONG WITH TABULAR AND GRAPHICAL OUTPUTS OF DATA FOR EACH OF THE OTHER CITIES. PROGRAMS WERE DEVEOLOED THAT SUMMED THE TOTAL NUMBER OF PERSONS IN MOTION AND THE TOTAL VEHICLE-MILES OF TRAVEL TRAVEL OCCURRING EVERY TENTH OF AN HOUR FOR A 24-HOUR PERIOD. FIVE SUBMODELS WERE USED TO AGGREGATE HOURLY TRAVEL INTO SIMILAR TIME GROUPS: WEE HOURS, MORNING, MIDDAY, AFTERNOON, AND EVENING. AREA-WIDE TRAFFIC COUNT DATA WERE USED TO DETERMINE TOTAL VEHICLE-MILES OF TRAVEL OCCURRING ON VARIOUS CLASSES OF HIGHWAY, AND AT VARYING DISTANCES AND ORIENTATIONS FROM THE CENTRAL CORE CITY, ON DIRECTIONAL AND NONDIRECTIONAL BASES.

Urban traffic studies from aerial photographs

Abstract: Two problems concerning the use of aerial photographs for conducting traffic studies in urban areas are considered in this paper: (1) Suitable procedures requiring simple equipment and methods and the appropriate formulae for determining the traffic characteristics of density, volume, traffic count, speed, composition; (2) Problems relating to flight planning for traffic surveys from the points of view of duration of photography and the scale of the photography from considerations of the reliability of the determined traffic characteristics, vehicle identification, and also economy The conclusions concerning the flight planning were applied in a test flight from which traffic data were determined as illustrated in a sample calculation

Estimation of 18-kip equivalent on primary and interstate road systems in virginia

Abstract: FOR FLEXIBLE PAVEMENT DESIGN PURPOSES, THE VIRGINIA DEPARTMENT OF HIGHWAYS USES THE AASHO METHOD OF DETERMINING THE 18-KIP EQUIVALENT SINGLEAXLE LOAD,. THE EVALUATION OF THE EAL-18 IS BASED ON ON-LOCATION TRUCK AXLE WEIGHT STUDIES . THESE STUDIES ARE EXPENSIVE AND TIME-CONSUMING AND HENCE ARE NOT USED FOR PAVEMENT REEVALUATION AND REHABILITATION. FOR THIS REASON, A METHOD BY WHICH THE EAL-18 COULD BE ECONOMICALLY AND QUICKLY ESTIMATED FROM THE ROUTINELY AVAILABLE RECORDS SEEMED DESIRABLE. THESE RECORDS ARE THE YEARLY TRAFFIC COUNT ON EACH SECTION OF THE PRIMARY, INTERSTATE, AND ARTERIAL SYSTEMS AND THE YEARLY RECORD OF THE WEIGHTS OF VEHICLES USING THESE SYSTEMS. IN THIS INVESTIGATION, SEVERAL METHODS WERE TRIED TO DETERMINE THE BEST ONE FOR ESTIMATING THE EAL-18 FROM ROUTINE AVAILABLE RECORDS. A METHOD INVOLVING THREE EQUATIONS WAS CONSIDERED THE BEST FOR THE FOLLOWING REASONS: IT PROVIDES A VERY GOOD CORRELATION WITH THE AASHO METHOD, DATA FOR ESTIMATING THE EAL-18 ARE READILY AVAILABLE FROM THE YEARLY REPORTS PUBLISHED BY THE VIRGINIA DEPARTMENT OF HIGHWAYS (AND THOSE OF MOST OTHER STATES), AND THE METHOD ACCOUNTS FOR THE WEIGHT AND COUNT OF TWO-AXLE, SIX-TIRE SINGLE UNITS, THREE-AXLE SINGLE UNITS, AND TANDEM TRAILER TRUCKS SEPARATELY, THUS PROVIDING GREATER ACCURACY IN THE EVALUATION. IT IS SHOWN THAT, EVEN IF THE ESTIMATED EAL-18 DEVIATES GREATLY FROM THE AASHO VALUE, THE EFFECT ON THE ULTIMATE PAVEMENT DESIGN IS VERY LITTLE. THE APPROACH COULD BE USED TO DEVELOP TRAFFIC PROJECTIONS IN CASES WHERE LOAD METER STUDIES ARE NOT FEASIBLE, FOR EXAMPLE, ON ROADS WITH HEAVY TRAFFIC WHERE VEHICLES CAN BE COUNTED BUT NOT WEIGHED.