Variations on a Theme

Isochronic - Single Time

This is a work in progress of generating an isochronic drive time map of the United States.  In this case, it is from the City Center of Saint Louis, Missouri, USA, however once I get the initial data filled out, I should be able to automate the process and generate it from an arbitrary point.

The first attempt, above, was a hand drawn affair only featuring a few dozen cities.  Below, you can see a map made with Tableau that contains all the data thusfar that I've collected.  This is not the ideal final form of what I intend to make - for that I'd rather have a map that resembles a topographic map, with concentric circles spreading out in quarter hour increments.  Ideally, this will show some interesting abberations of geography, roads, and speed limits.  I anticipate seeing quagmires show  up around lakes and mountain ranges.

 Unfortunately, presently high temporal resolution is only available at t<24 hours, above one day, the resolution is only one hour using Google maps.

In the end I realized that Tableau wouldn’t quite do what I needed, so I looked into using Open Street Maps data. Generating maps from only ~4000 data points was not enough to get a map with enough detail to see trends from across the continental United States.

To begin with, I set up a local OSRM server and downloaded the North America map, which contains the Canada, Mexico, and the United States, giving me all the data I was interested in. To get more and more data points I used OSMFilter to make a CSV with the coordinates of all the fueling stations, cities, towns, ranches, farms, parks, etc. in North America.

Then using a script derived from Ilia’s experiments with map times, which can be found on GitHub, I processed the ~550,000 locations and received a new CSV with the drive times to each of the locations (that could be driven to). These locations were also subject to the time limitations from Google maps, but also trend longer for drive times than Google

The resulting data was then processed in QGIS, using the Contour plugin to generate the contour lines. The base map of the US and road maps were taken from the US Census bureau.

Next, we need to make it look professional, and speed up the code to generate the maps!

Let’s start with the code to keep you in suspense. Well, let’s just point you to the github project and leave it at that: https://github.com/IRLf/osrm_table_generator

Now, to the “professional” looking results:

The remainder of the maps can be found in high quality on my Flickr page here: https://www.flickr.com/photos/66988833@N02/albums/72157713475482167