<![CDATA[Flooding in Banda Aceh may disrupt access from evacuation shelters to referral hospitals, making ambulance route planning essential to integrated emergency response. This study applies GIS-based Closest Facility Analysis (CFA) to determine minimum-cost routes from 18 evacuation shelters to six referral hospitals. Road network, shelter, hospital, flood inundation, and administrative boundary data were standardized to WGS 1984 UTM Zone 46N, checked for topology and connectivity, and built into a network dataset in ArcGIS Pro. Shelters were defined as incident facilities and hospitals as destination facilities, with theoretical distance and travel time as impedance attributes (assuming an ambulance speed of 60 km/h). CFA produced 18 routes with distances of 0.66–4.49 km and travel times of 40 seconds to 4 minutes 29 seconds; the mean distance was 2.10 km and the mean travel time 2 minutes 7 seconds, with 11 routes (61.11%) no longer than 2 km. The shortest route connects SMP IT Nurul Islah with RSUD dr. Zainoel Abidin, while the longest connects Escape Building Ulee Lheue with RS Harapan Bunda. CFA can identify the spatial accessibility of shelters to healthcare facilities through the actual road network and provides route, distance, and travel time information as a basis for preliminary ambulance referral planning. Operational implementation, however, still requires integrating dynamic information such as traffic conditions, affected road segments, and hospital service capacity.]]>
