Stefan Wehrmeyer is the developer of Mapnificent, a site that shows how it is possible to travel on public transportation for over 20 cities throughout the world. The application interface provides a slider control to adjust maximum travel time. As the slider is adjusted, the highlighted area on the map showing travel range expands and contracts. The visual feedback is impressively fast.
Mapnificent uses public GTFS from the GTFS Data Exchange.
For more, check out Stefan’s blog post, visit the site, or watch the video below.