distribution, and often exhibits overdispersion. Based on a survey of 180 countries by the
World Health Organization in 2015, Thailand is the second unsafety country for driving on
roads, with 36.2 deaths per 100,000 population. In this study, a total of 20,226 road traffic
accidents in Thailand in 2015 were investigated. Factors associated with the injury counts
per accident were disclosed using the Conway-