GIS4043 - Week 12 - Geocoding

Optimal Route Between Three Lake County EMS Stations

This week's lab was about Geocoding, Using Network Analyst, and Model Building.  We began by downloading data from the U.S. Census Bureau site.    Specifically, it was a Tiger Line shapefile for Lake County, FL; with this file we created a feature class for our geodatabase, Lake_Roads.   We also imported address information for Lake County EMS stations from a provided Excel table.  From our geodatabase Lake_Roads feature class we could create an Address Locator.  Finally, we could geocode the addresses for the EMS stations from the table we imported!  This was a frustrating experience but I learned how important it is to geocode!   After this process I realized how difficult it can be to correctly geocode/match addresses.  Thankfully, two-thirds of the addresses matched via our Address Locator.   Finding address matches for the remaining one-third required some zooming and hunting skills and the assistance of Google Maps and Bing Maps.  Some of the station addresses did not match due to field naming nomenclature.   A county road had the same number as a state road.   A state road was listed as a state highway.  Sometimes only one side of the street was numbered.  Even some of the rematch candidates were not good options.   I usually picked an address match from the map after a Google Maps and Bing Maps search.

With all of our station addresses correctly matched we then selected three stations to analyze with Network Analyst.  Using this tool we created an optimal route of travel between the three stations based on the amount of travel time.  U-turns were allowable anywhere but one-way and turn restrictions had to be followed.  I selected a station location in each region of Lake County to create my analysis set (Northeast-#141, Northwest-#241, and South-#341).  Using the Network Analyst Tool, Route, I was able to create a route based on travel time between the three distances.   I chose to start my route in the Northeast at Station #141 and then travel to Station #241 in the Northwestern part of the county and then finally end at Station #341 in the South.  I also tried changing the sequence of stops but the order sequence described above produced the optimal route which covers 32 miles in 43 minutes when started on a Monday at 8am.

In the final section of the lab, we were introduced to ESRI's Model Builder.  The training model was built to determine the locations of gas leak areas around schools in Fort Pierce.  The Model Builder helped me see the big picture from above the tree line of what we've been doing in some of our previous labs.  Using a model to manage geoprocessing operations makes sense.   Once a model is built you can copy or modify it for another use simply by making changes to either inputs or tools and share it.  We learned the basic elements of Model Builder; what the different shapes represented and whether they appeared filled with white (not ready to run), color (ready to run), or with a shadow (already run).

ESRI Gas Leak Model