This is really cool. I'd love to read the source code for those little sensors. And explore the 3D models! There's probably some security protocol that means non-TfL people can't just sift through their data. They have been putting publicly available live transport data on their API, however! And since this is a government body, it also includes information about roads, accidents, bicycle paths...
Yeah, I vaguely remember seeing a website showing some really good schematic maps of existing Underground stations but I can't remember the link. The TfL API is definitely a work in progress (the bicycle path information was just added, AFAIK) so we will see in time how much more information they put up! Their goal to put all of the information that is accessible through the HTML site in the JSON API is something that I wish a lot of other organisations would emulate. Unfortunately, this runs counter to the advertising-supported model of online content, given that one can very easily scrub out advertising from JSON/XML... So something will have to give, right?