Risk incident analyses in the transportation of anhydrous ammonia as an emerging clean energy resource

Anhydrous ammonia has seen a rapid increase in demand due to recent developments in clean energy technologies. As it is a potential carrier of hydrogen, the transportation industry is currently facing significant logistic challenges as well as safety risks. Based on the causes and effects, this study categorizes incident patterns based on the historical incidents from 1971 to 2021 in the United States during transportation. Analysis of temporal patterns revealed that government regulations and improvement of safety infrastructures have made the biggest impact on lowering incident rates. Spatial analysis methods are also applied to understand the relationships between these incidents and spatial factors, such as land area, number of ammonia production facilities, total average production capacity, and total length of freight railway and highway in each US state. The spatial and temporal patterns and interpretations provide safety references to manage the growing hazardous transport in clean energy.