Mathetharan, Vijayarajah creator Yordphol Tanaboriboon Chairperson Morisugi, Hisa Examination committee Chen, Jian-Shiuh Examination committee The Government of Japan Scholarship donor text th Bangkok Asian Institute of Technology 1997 monographic eng

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140 p.: ill. Accurate knowledge of the current operational traffic behavior inevitably enhances the reliability of planning and design of the highway facilities. The use of an accurate value of basic capacity is necessary in calculating service flow rates which are the close representatives of traffic behavior. This study was canied out as a stepping stone towards the determination of the basic capacity of uninterrupted flow highway facilities in Thailand. Speed-flow-density analysis was used as primary methodology to determine the capacity. Average speed difference distribution method and average minimum time headway approach were used as benchmark tests. A photographic technique through video recording was used to collect relevant data from one of the busiest expressways in Thailand, namely the Chalerm Maha Nakhon Expressway. The data were extracted manually from the recording. The extracted data were analyzed to find the key variables such as speed, flow and density and other necessary parameters such as headway and passenger car equivalents (PCE) which are used to find the focal point, the capacity. Seven appropriate mathematical models which relate speed, flow and density were hypothesized and then calibrated to find the functional fit to the collected data. The graphical representation of models with different curves were analyzed in detail. The analyses were carried out on a separate lane basis and on a combined average lane basis. The analyses were done separately on data acquired in 5-min and 15-min intervals. The capacity values for different cases were found using the calibrated model expressions and graphical representation of models. The average value of capacity for uninterrupted flow highway based on the speed-flowdensity approach was found to be about 2400 passenger cars per hour per lane (pcphpl). This obtained capacity value is 16.67% higher than the value of 2000 pcphpl currently used in Thailand. Moreover, the value is 9 .17% higher than the benchmark value previously obtained by using minimum time headway approach in Thailand. However, the obtained capacity value is in concordance with the value that the Highway Capacity Manual (HCM) predicts. A thesis submitted in pa1iial fulfillment of the requirements for the degree of Master of Engineering, School of Civil Engineering Thesis (M.Eng.) - Asian Institute of Technology, 1996 Highway capacity Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B14177 http://203.159.5.9/ait-thesis/detail.php?q=B14177 190698 20260818090418.0