WMATA recently announced that they’re looking to improve bus service on 16th Street. There’s another public meeting on September 23; be sure to visit the Metrobus 16th Street Line page for details. (Emphasis mine.)
They’ve already had one public meeting (PDF) on July 15, and the attendees broke into small groups to discuss the current problems with the route (mostly bus crowding, bunching, schedule adherence and travel speed issues). According to a recent Washington Post article, Metrobus operates about 75% “on-time” for all routes, defined as between two minutes early and seven minutes late. There’s probably a high amount of variability between lines.