Cool site shows next BART trains overlaid on Google Maps

I study Web site "mashups" but I don't know exactly how this site was created, or how it's maintained. But it's COOL! It overlays the BART stations on Google Maps and then pops up a list of the next trains coming to each station, and where they're headed. I'm sure this is based on BART's printed schedules and not real-time information. But wouldn't it be cool if BART created something just like this where the info was updated every few minutes?