The timing for a riders union in Philadelphia is right, transit advocates say. SEPTA is trying to improve Regional Rail's on-time performance and is in the midst of a two-year review of its bus network that could lead to substantial changes. The bus network review, in particular, has the potential to improve service for some communities while reducing it in others. Riders should have a loud and influential voice in that process, said Dena Driscoll, a co-chair for 5th Square.