Week 12 - Geocoding, Network Analysis, and Model Builder

This week in GIS4043 we covered geocoding addresses, used the network analyst extension to create a route, and edited a model in Model Builder. It was quite the whirlwind week!

The map below shows the results of the geocoding and network analyst exercises. The addresses were geocoded from a table of EMS locations within Lake County, Florida. To get the geocoding down we first created an address locator. The points on the map below are the results of the geocoding process (and the subsequent address matching process - which basically involved matching problem addresses using Google Earth and the Lake County EMS provider website).

The route was created from various stop points created at random using the network analyst tool. Basically what is shown below is the optimal route based on pre-assigned conditions (in my case, the best route at 4:30 p.m. on a Monday with U-Turns allowed). The network analyst tool navigated through all of the road data to find the quickest travel times and came up with the route below. If you're interested, the estimated travel time is 11 minutes (stopping at both locations), and the total distance traveled is 8.3 miles.

Geocoded EMS Locations and Optimal Route generated by Network Analyst.

For me the most difficult part of the exercise was the geocoding. It seems so simple - match an address with a location, right? Well, not entirely. The unmatched areas didn't really line up well with reality, and what was even more disturbing is that both Google and Bing maps had serious placement discrepancies. In the end I was left with using Google aerial map view (to look for possible EMS-like buildings) and the Lake County, Florida EMS location webpage.

Both options really messed with my comfort level concerning data accuracy because, well, it's not accurate. However I do realize that if that were my job, I may not EVER be able to go out into the field to ground-truth those address locations. The bigger lesson here was that data entry problems really do create bigger problems down the road...