The development of chemical emergency response system for Thailand expressway

The transportation of hazardous materials ( Hazmat) plays a vital role in Thailand’s industrial, agricultural, and public health sectors. Due to Bangkok’s high traffic congestion and volume of Hazmat vehicles, chemical incidents on expressways pose significant risks. The Expressway Authority of Thailand (EXAT) has developed an extensive expressway system, yet emergency responses are often hindered by human errors such as miscommunication and inaccurate data. This study aims to reduce such errors by creating a decision- support system for chemical spill responses on expressways. The research used a multi-stage methodology. A Delphi method with 17 experts identified key factors influencing emergency route selection, categorized into five main components: Travel Time, Chemical Information, Social Impact, Traffic Data, and Fire Station Effectiveness. These were weighted using Analytic Hierarchy Process (AHP) and Fuzzy AHP to address uncertainty in expert opinions. A computer program integrating real- time traffic, GPS data, weather conditions, and chemical hazard modeling ( via ALOHA and CAMEO software) was developed to simulate spill scenarios on the Chaloem Mahanakhon Expressway. The cost function was calculated using normalized weights to identify the most suitable emergency response route. Results showed that the Bon Kai route consistently had the lowest total cost in both daytime ( 0 . 4 8 4 ) and nighttime ( 0 . 4 7 8 5 ) scenarios, due primarily to its high fire station readiness. This indicates that the system successfully supports emergency planning by optimizing route selection. The study recommends integrating such a model into EXAT’s real- time response protocols to enhance safety and reduce impact during chemical incidents