Queues are a part of life.
In the United States, people spend a total of 37 billion hours each year waiting in line. Queues are everywhere - from waiting at the supermarket checkout, to waiting for an ambulance dispatch officer to send you an ambulance, or circling above an airport in a holding pattern. Dealing with queues is very important for a city s Emergency Response System - such as for the Police, Fire Brigade or Ambulance. The time factor is usually very critical. For example, the probability of a police officer arresting an offender near the scene of a crime is highest within two minutes of the crime being reported.