The Sun Tran app is Tucsons real-time bus and streetcar tracking tool. Easily navigate on Sun Tran and Sun Link with accurate real-time arrival predictions, track the current vehicle location, see if it is on time, and view how full it is before going to the stop. Locate the nearest bus or streetcar stop and plan a trip using an interactive multi-route map. Stay informed with service alerts, departure times and stop reminders.