Sourasay Phoumavong creator Fukuda, Atsushi Chairperson Yordphol Tanaboriboon Examination Committee Mori, Hiroshi Examination Committee The Swedish International Development Authority (SIDA ) Scholarship Donor text th Bangkok Asian Institute of Technology 1991 monographic eng 56 p. In transportation and landuse planning , the traffic demand and travel pattern in certain areas can usually be predicted using an 0-D matrix. Many models have been developed to estimate an 0-D matrix, however , unfortunately , these models cannot be applied in many developing countries, due to their financial constraints, since these models require enormous surveys and could be very expensive. Therefore, it becomes necessary to seek a possible way to develop a model that estimates an 0-D matrix without requiring extensive surveys. Recently, a Combined Incremental Distribution Assignment · (CIDA ) model was developed that enables a feed back process between trip distribution and trip assignment to improve the existing O-D matrix. The main purpose of this model is to update an existing trip matrix using the available data. It was shown that t h is model is applicable to update an existing 0-D matrix. However, it was strongly recommended to carry o u t a validating of the model with real data, because artificial data have been applied in that research. This study attempts to get an 0-D matrix for Vientiane, Laos, updating the CIDA model and using real data from the actual study area. Due to a lack of an existing 0-D matrix in developing countries like Vientiane, the CIDA model is adopted to obtain a new model using the trip generation through gravity model to get an initial O-D matrix. Using the mean of difference between the estimated and observed traffic volumes the rate of accuracy was analyzed from the present given road network. The limited condition of the high variation ± 10 percent for the comparison between estimated and observed traffic volumes on links showed inefficient results by iterations for the model because of the inadequate traffic count data. However , some links can reach this condition between estimated and observed traffic volumes. Although the results showed an unstable model, it could serve as a theoretical basis for further research. A thesis submitted in partial fulfillment of Requirement for the Degree in Master of Engineering, School of Engineering and Technology Thesis (M.Eng.) - Asian Institute of Technology, 1991 Traffic engineering Laos Vientiane Mathematical models Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B17564 http://203.159.5.9/ait-thesis/detail.php?q=B17564 251198 251198 20260817162832.0