Rail transport, characterized by its exclusive right of way and high service capacity, has received increasing attention in the international transport community. According to the statistics of Taiwan Railways Administration (TRA), the TRA served approximately 232.8 million passengers in 2014 with an average daily volume of 637,881 passengers, an increase of 4.99% compared to that of 2013. The constant increase of passenger trips has indicated that TRA plays a crucial role for intercity transport services in Taiwan. In terms of traffic accidents for the TRA system, it is relatively few compared to that of the highway system. Nevertheless, in case of a rail accident, it usually causes significant number of casualties and different degrees of impact, even induces some external costs (such as train delay, locomotive engineer’s psychological impact, and injury recovery and facility maintenance expenses, etc.). Past studies concerning rail accidents mainly focused on highway-rail grade crossing accidents. Investigation on rail trespassing incidents is relatively rare. Currently, the operation mileage of the TRA system is 1061.3 kilometers including a total of 91 kilometers of the branch lines. Along the main and branch lines of the TRA system, there are 466 grade crossings with different control means (mainly active control by quadrant-type gate). Compared to those traffic accidents occurred on grade crossings, the accident frequency and potential impacts of rail line trespassing incidents along the entire service scope of the TRA system should not be ignored, and this topic is deserved in-depth investigation. To resolve the above research question, this study is proposed to investigate the casual relationship between rail trespassing incidents and a set of covariates using the west main line in Taiwan of ten-year incident dataset provided by the TRA (2005-2014) by Geographically Weighted Regression Model, which is developed to further evaluate the effects of local characteristics on the occurrence and/or impact of a rail trespassing incident. It is expected to provide the TRA and related government offices with a reference in preparing rail line trespassing incident prevention strategies from the general public.