Patteera Jensupakarn creator Kunnawee Kanitpong Chairperson Surachet Pravinvongvuth Examination committee Piyapong Jiwattanakulpaisarn Examination committee Royal Thai Government Scholarship donor Asian Institute of Technology Fellowship Scholarship donor text series technical report th Pathum Thani, Thailand Asian Institute of Technology 2017 continuing eng 70 leaves : ill. In Thailand, the number of car crashes and the level of severity in these kind of accident have been comprehensively increasing. To reduce the accident severity, it is necessary to find out the factors that affecting to the level of severity first. In this study, macro-level of accident data were analyzed to identify the accident contributing factors influencing severity level of car crashes, by using secondary data of accident report on national highway in year 2010 to 2014. The data were separated to three scenarios; passenger car, pickup and both passenger car and pickup accident. The Ordinal Logistic Regression Model were used to analyze the data. In addition, micro-level data of passenger car accidents were collected by using in{u2013}depth accident investigation techniques and the event data recorder (EDR)technology in order to study and compare the results related to driver{u2019}s behavior at crash which obtained from two techniques. Findings from this study indicate that time of crash, vehicle/road user involved, type of crash, location of crash and cause of accident are affecting to the level of severity in car crashes. Moreover, the micro-accident analysis shows that the data retrieved from EDR could be used to confirm the in-depth accident investigation analysis method which is useful for improving in-depth accident investigation techniques in Thailand. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Transportation Engineering, School of Engineering and Technology Thesis (M. Eng.) - Asian Institute of Technology, 2017 Traffic accidents Analysis Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B04153 http://203.159.5.9/ait-thesis/detail.php?q=B04153 180912 20260817162412.0