This is a mashup to overlay demographic info with the all the major mass transit routes in the San Francisco Bay Area.
This master branch you’re looking at has the Python code used to generate the data files used by the visualization.. The visualization itself is in the gh-pages branch.
To generate the JSON file that the mashup reads data from, run grab_routes.py.
To change it to graph another city, change ALL_GTFS_PATHS in config.py to point to other GTFS feeds available from the transit agency of your choice.
To graph other dimensions, change the MEDIAN_INCOME_TABLE_NAME constant in config.py to some other American Community Survey column name. A list of column names is on p45 of this PDF. Also, be sure to use your own API key!