Trying to display LineStrings, may need deeper changes or change the lines to Polygons
Can use the districts json just fine, but the json I with polygons generated in ipython with shapely is coming out as unclickable lines.
This was actually working for a while but chrome was loading an old cached json, firefox reloads the real one from disk.
Fairly good display of traffic volumes, though resolving what to do with old data (make it more transparent?), adding directions when available would be nice.
Need to put all the properties in a list and sort them by date.
Don't show the buttons, show the arterial class (also TODO find a reference that explains them