Master Street Addressing Guide (MSAG)
In order to bring Enhanced 9-1-1 technology to Nez Perce County and the City of Lewiston in 2002 County and City staff had to first build a Master Street Addressing Guide (MSAG). The MSAG is telephone number and address data that provide the Automatic Number Identification (ANI) and Automatic Location Identification (ALI) that allow 9-1-1 call takers to help determine where a call is originating from on a wire-line phone. Wireless phones provide a latitude and longitude that helps in getting a possible location for wireless calls to 9-1-1. In addition sections of the County and City are designated with Emergency Service Zones (ESZ) and are identified by an Emergency Service Number (ESN). Data are entered into each ESZ that identifies the responding law enforcement, fire, and medic units for each corresponding ESN and all of this this information;ANI, ALI, ESN populates a window on the 9-1-1 call takers computer screen and helps them to provide the dispatcher with as much information as possible to get the correct response units rolling to the scene of the emergency as quickly as possible. This information is supplemented by questions the call taker asks the caller and relays to the dispatcher who provides the information to the responding units.
All of this data is also geocoded by the Nez Perce County GIS Coordinator and maintained on a master map of the County. The maps also include layers of other data that help identify places such as parks, rivers, lakes, streams, and community buildings and grounds. The call takers have a map that utilizes the data and populates the address for wire-line call or a laitude and longitude for a wireless call. In addition the ESZ data also populates on the map to help remind the call taker what response units need to be sent for that zone.
For more information regarding mapping visit:
NENA (National Emergency Number Association)
ESRI (Environmental Systems Research Institute)