Identification of Hazardous Materials Truck Stops and Their Spatio-Temporal Distribution by Using GPS Trajectories

Existing studies on hazardous materials trucks mainly focus on route selection and risk assessment during truck movements, neglecting the potential threat to the areas which surround truck stops. In this paper, we propose a novel algorithm to identify the truck stops from GPS data based on the temporal and spatial attributes, and classify the categories of hazardous materials truck stops according to the Chinese National Economy Industry Classification System. GIS spatial analysis method is then employed to establish the temporal and spatial distribution of different categories of stops. Taking the trajectory data of hazardous materials trucks in Chengdu, China, as the sample dataset, the study shows that the trucks are mainly used in service, manufacturing, and wholesale and retail industries, and more than 80% of the stops are located outside the urban core area. Concerning stay time, nearly 60% of trucks stay in the identified areas for less than 2 h and only 20% of trucks for more than 9 h. The peak periods for the arrival of the trucks at most stops are 9–12 a.m. and 2–10 p.m., and stops on weekdays have less influence on their spatial distribution. Such results can provide decision-making support to government departments in their designation of operation sites, regulatory facilities, and transportation corridors, and transportation companies can arrange transportation routes and travel time according to the management measures thus taken.