Two signs, in fact. After many years, someone or some agency has finally posted permanent metal signs on the two platforms at Centerville that say:
...in large, bold, block letters. Not paper signs that get washed away or other half measures.
This should help somewhat in reducing the number of people going to the wrong platform for their trains. Now, however, we have to rely on the dispatchers routing trains to the tracks for which they're scheduled, because there is no way to communicate last-minute changes to the passengers at the station. The electronic signboards are only good for system-wide notices and automated ETA information for trains.