The Streamline Bus system of Bozeman, MT is a good example of public transit service for small cities. They even have a real-time tracker online system which you can see the route maps, real-time arrival times, and real-time location of the buses.
"Streamline's ridership continues to grow beyond expectations. Rides in 2009 exceeded 198,000 and 233,000 in 2010. Rider statistics for 2011 grew again to just over 242,700."