Carfree is an app for determining the distance traveled and emissions saved by traveling by bus, BART, bike, or on foot. The backend is an API built on Ruby on Rails that uses the 511.org, BART, and GoogleMaps APIs. 511.org data is stored in a Postgresql database, from which rake tasks querying the Google API were used to populate a redis database with the distances between each AC Transit bus stop on every route. The frontend is built in Ember.js. Chart.js was used for pie charts of miles traveled and emissions saved.