Steven can plan

Like any good website owner and author, I track statistics (or analytics as people like to call them now). The most important information the reports tell me is how people found my site: either through keyword searches, or links from related webpages.

Recently, a visitor came across my site because of a search for “amtrak routes gis.” I suspect they were looking for shapefiles they could load into Geographic Information System software containing Amtrak routes and stations. My blog showed up on the second results page in Google and they came to my post, “Why Amtrak’s not on time,” about the factors that influence the passenger rail company’s timeliness. The page doesn’t have what the visitor wants.

I decided to update my page, “Find urban data,” to aid future visitors. Also, if one person is looking for this information, it’s likely that others want it, too. I found the information, “amtrak routes gis,” in two places and in two formats.

First, the United States Department of Transportation’s Bureau of Transportation Statistics publishes national data in the “National Transportation Atlas.” You can find a shapefile with Amtrak stations. For Amtrak routes you must download the railway network shapefiles and then filter the information for the attributes that describe Amtrak.

The second source is an interactive KML file (more about KML) that you can load into Google Earth, view in Google Maps, or manipulate in another KML-compatible application.

The KML file is an important format in which to share locational data. KML was developed by a company called Keyhole, which Google purchased in 2004, and subsequently released Keyhole’s flagship product: Earth.

A Keyhole Markup Language file is a way to display on a map (particularly a 3D globe of Earth) a collection of points with a defined style. Google has added more functionality and style to the KML format, expanding the styles that can be applied and the information that can be embedded.

KML, like XML (eXtensible Markup Language), is extremely web-friendly. For a web application at work I developed, I included this PHP class that creates an KML file on-demand based on a predefined database query. The file contains locations and attributes of recently installed bike racks in Chicago. EveryBlock imports the file and its information into their location-based service, aggregating many news types around your block.

But a KML file is more important than being the native file for use within Google Earth. It’s an open source text file that can be manipulated by a number of software programs on any computer system on earth (or read on a printed page). It’s not encoded, like shapefiles, so I can read the file with my own mind and understand the data it would present in a compatible map viewer. I see lines of organized syntax describing points and polygons, listing their attributes in plain language.

Have you ever tried to see the “inside” of a shapefile? Only GIS programs can read them for you. KML provides data producers and consumers the opportunities to keep data open, available, and easy to use. We need locational data for our work, and we need tools to help us use it, not hide it.