I recently did a stint writing documentation for a public safety software company. One of the core modules of their product line is the mapping module, so I had an opportunity to get an extremely intimate look at the inner workings of this kind of GIS system. Properly designed and deployed, such systems are very useful. Improperly designed, or inappropriately used, however…not so much. Part of my charter was to write documentation that trained end-users on the ins and outs, and in how to appropriately apply the mapping tools at their disposal. As a life-long map junkie, the assignment was tons of fun.

:-)

nic

This comment has no real content, other than to thank you for putting the time into this explanation. It’s really fascinating to me that it’s possible to have such detailed geographic information available at the push of a button – though I wouldn’t put it past the City of Verona to put fire hydrant locations or every single telephone pole on their next bicycle map.

Thanks again!

The fact that it’s an artificial map construct based on database information doesn’t change the fact that it’s a crappy map, merely that somebody was tasked with producing it by entering the raw datya into the database (while creating subcategory 5). Essentially, the map itself is a semi-accidental byproduct of the data entry process.

GIS database maps are generated for a given municipality or other geographically delineated area. Usually by the civic agency responsible for administering the area; often for public safety and utility service management purposes. So you’ll geta basemap, with the general outlines of the town boundaries, then various primar layers. One for physical features such as hills, creeks, etc. Another for “public spaces” like parks and playgrounds.

The point, of course, is to maintain a single mapping database that provides down-to-the-micron accuracy of placement for anything that any municipal agency might need to be interested in. Fire hydrant locations, for example. Electrical substations and distribution networks, including every single telephone pole. Stuff like that.

So, say a fire alarm is tripped at 120 S. Main St. The fire department’s Computer Aided Dispatch (CAD) system instantly displays a map showing where exactly where the fire alarm box is located, based on the information on the “fire hydrant” layer of the municipal GIS database. A display on the fire truck shows exactly where the truck is currently located, and the shortest route to the fire alarm box. Same for the police department.

When the first responders arrive at the box, they radio back further information: the building on fire is actually at 126 S. Main. The CAD operator updates the information, and the CAD system spits out an updated map to all the remote consoles. This one might show where the closest hydrants are; which service lines those hydrants are on, etc. Further on-scene reports say the fire is larger and needs a second alarm response and an ambulance or three. More map updates happen, all generated on the fly from the GIS database. Now we’ve got traffic routes for multiple fire companies, police, ambulances, etc. Both to and from the scene, back to hospitals. Additional GIS layers show the traffic department which intersections will be affected, so any remote controls for traffic lights can be established to allow fast movement of response vehicles. Another GIS layer connects to the property database, which lets responders know how many people live/work in the building, who they are, and so forth.

The utility of such a GIS database is obvious. Unfortunately, for “mundane” things like creating bike trail maps for public use, they’re complete overkill.

And in this case, results in a very crappy map.

Also, Daniel: I think the Sugar River disappears to indicate where there are bridges or some sort of overpass. I make no claims about the logic of this approach; I’m guessing based upon my knowledge of the trails and local terrain.

The problem is that they decided that throwing this map on the city website under the “Bicycle Route Information” was a good idea. Wait, unless Verona is a colony of civic employees. I’d believe you if you told me that it is.

Also, it’s been three years since these paths were “nearly existing.” That leaves me very uncertain about their current state. If nothing has changed, they might as well sneak in there and change that 6 to a 9 so that the map appears current.

Hilariously, though, I realized in reading this that the third house from the corner of W. Verona Rd and S. Main would actually also be the third house from the corner of Paoli Rd and S. Main, as all the lots on Main south of W. Verona Rd are commercial lots. Park Bank, World of Variety, Miller’s Grocery, a coffeehouse, etc.

Although what this really says about me is that I spend far too much time in Verona.