A Comprehensive Survey on the Ambulance Routing and Location Problems
  In this research, an extensive literature review was performed on the recent
developments of the ambulance routing problem (ARP) and ambulance location
problem (ALP). Both are respective modifications of the vehicle routing problem
(VRP) and maximum covering problem (MCP), with modifications to objective
functions and constraints. Although alike, a key distinction is emergency
service systems (EMS) are considered critical and the optimization of these has
become all the more important as a result. Similar to their parent problems,
these are NP-hard and must resort to approximations if the space size is too
large. Much of the current work has simply been on modifying existing systems
through simulation to achieve a more acceptable result. There has been attempts
towards using meta-heuristics, though practical experimentation is lacking when
compared to VRP or MCP. The contributions of this work are a comprehensive
survey of current methodologies, summarized models, and suggested future
improvements.
