A GIS-based Risk Assessment for Hydrogen Transport: A Case Study in Yokohama City

Risk assessment of hazardous material transport by road is critical in considering the spatial features of the transport route. However, previous studies that focused on hydrogen transport were unable to reflect the spatial features in their risk assessments. Hence, this study aims to assess the risk of hydrogen transport by road considering the spatial features of the transport route, based on a geographic information system (GIS). This risk assessment method is conducted through a case study in Yokohama, which is an advanced city for hydrogen economy in Japan. In our assessment, the risk determined by multiplying the frequency of accidents with the consequence was estimated by road segments that constitute the entire transport route. The effects of the road structure and traffic volumes were reflected in the estimation of the frequency and consequence for each road segment. All estimations of frequency, consequence, and risk were conducted on a GIS compiled with the information regarding the road network and population. In the case study in Yokohama, the route for the transport of compressed hydrogen was virtually set from the near-term perspectives. Based on the case study results, the risks of the target transport route were assessed at an acceptable level under the previous risk criteria. The results indicated that the risks fluctuated according to the road segments. This implies that the spatial features of the transport route significantly affect the corresponding risks. This finding corroborates the importance of considering spatial features in the risk assessment of hydrogen transport by road. Furthermore, the discussion of this importance leads to the capability of introducing hydrogen energy careers, with high transport efficiency and transport routing to avoid high risk road segments, as risk countermeasures.