Land Suitability Analysis for Emergency Medical Services Posts along State Highways: A Case Study of California

The quicker the response time of emergency medical services (EMS) to road crashes the higher the likelihood of survival. For example, the California Strategic Highway Safety Plan highlights the need to improve the response time and recognizes that 37% and 8% of the fatal crashes are 30 or more miles away from a trauma center in rural and urban areas, respectively. This paper seeks to: (1) demonstrate the viability of using spatial multi-criteria analysis in road safety management; and (2) provide a logical and consistent approach for identifying potential EMS locations. This paper adopted a multi-criteria analysis using the weighted linear combination method on raster data of various impact factors. The area selection criteria were: (1) closeness to probable road fatality locations; (2) distance from existing trauma centers; (3) proximity to existing rest stops; and (4) land availability. An EMS response time of 10 minutes, which is 3 minutes shorter than the national average, is used in this paper for demonstration purposes. Note that the specific criterion will be a function of the decision maker’s goal. The proposed methodology, which is a first step in identifying potential areas for EMS locations, was demonstrated on information from the state of California. It was found that of the 155,779 square miles of the land area studied, 24% were suitable, 7% were moderately suitable, and 69% were unsuitable for new EMS locations. In general, the rural areas along the west side freeway corridor, linking Los Angeles and San Francisco, are highly suitable.