Air EMS is a supplement to primarily land EMS deployment. Air would most often apply to a) inaccessible areas; b) extreme emergency response. In the later: extreme emergencies are supported by reliable and efficient communications networks and experienced asset management. In addition to the preliminary communications network, well-kept roads allow for faster response times.
"Road transportation network development is considered to be one of the keys to rapid modernization and development, especially in most development countries, investment for road construction and maintenance accounts for a substantial (excess of 20%) of development budgets. Road network provide accessibility and easy flow of traffic for both human being and movement of vehicles. It is discovered in our urban cities/towns the difficulties in accessibility and transportation of goods, services from one place to another due to inadequate planning and uncoordinated development planning which greatly affect access to some neigbourhood and facilities.
Road networks being the main network most country use, GIS concept like connectivity and accessibility could be used to enhance the opportunities available for the people and services providers to access places where they can carry out activities and even to foster development in the choice area." source: https://steemit.com/research/@matthiasjohn/road-network-information-systems-for-emergency-response