A Transportation Disruption Metric for Emergency Household Food and Water Access After Earthquakes

Large earthquake events may damage civil infrastructure systems, cascading to impact community emergency resource access. For example, after the (M) 7.8 and (M) 7.5 Kahramanmaraş Earthquakes in Turkey (2023), many households with water service outages were forced to travel across damaged transportation networks to access emergency food and water supplies. Transportation system performance is often measured in minimized economic cost across a network. However, this metric may not include the social implications of infrastructure system disruptions. For example, vulnerable households often suffer disproportionate hardships from infrastructure interruptions and disparities in accessing emergency resources post-disaster. Here, we develop a household-level metric of single-mode-destination accessibility loss to estimate the median percentage (%) increase in travel time for emergency food and water resource access in households impacted by water service outages post-disaster. We present an application of the metric in a case study of the HayWired earthquake scenario, a hypothetical Mw 7.05 earthquake on the Hayward Fault in the San Francisco Bay Area (USA). We estimate a median percentage (%) increase in travel time (over a baseline) for emergency household food and water access using an origin–destination matrix analysis. Our results identified areas with disproportionate increases in travel time for emergency household food and water resource access in several communities. The metric could be applied to help civil engineers rapidly prioritize emergency road and water distribution repairs that may disproportionately impact vulnerable communities as they access life-sustaining emergency food and water resources.