The 'next bus' signs around here are all based on realtime GPS-tracking from the buses ('free wifi' is often piggy backed on the data connection the bus thus ha

The 'next bus' signs around here are all based on realtime GPS-tracking from the buses ('free wifi' is often piggy backed on the data connection the bus thus has to maintain. I've seen buses run so late that they bunch-up and even to the point where they asked us to switch to the front bus so the rear bus could be taken out of service, once, and never seen the displays at the stops get too confused.