I recently became aware that Translink, Queensland’s public transport provider, openly publishes both a GTFS (General Transit Feed Specification) Static dataset and Realtime feed. The GTFS Static dataset provides information on routes, schedules, stops and pathing, while the Realtime feed provides information on current vehicle lat/long coordinates and delay information.
I created a web app to visualise the realtime feed on a map and supplement it with the static data (direction and vehicle type).
The initial version used moving markers to simulate vehicle movement. Speed was based both on static timetable information and adjusted using real-time speed (calculated from the distance traveled between updates of the feed). While the moving markers were appealing, the crude design of the web app was such that these calculations were performed by the browser instead of the server to offload processing. This resulted in a lot of data being sent to the browser, and was unsuitable for mobile devices with limited data caps. I ended up removing this functionality when optimising the reduction in data exchanged between the client and server.