In Aberdeen we have digital displays mounted in most of the bus stops, in fact most major cities in the world probably have similar signs. The signs get their data via radio broadcasts, these broadcasts have in fact been captured before and reverse engineered.
For a long time I have been thinking about doing a similar thing and figuring out the bus information that is in the air. I am sure I will get to it one day.
Well this morning as I headed off to work I caught a technician in the act of debugging one of these signs. I grabbed a quick picture of the guy working, but I didn't want to bother him.
It looked like the tech was using a serial cable from his laptop up to the display. The antenna on the bus shelter looked much larger than the normal ones.