The "S" stands for "special." Trains marked with an "S" operate every VRE service day, and they are typically the only trains that operate when VRE is on its "S" schedule. "S" schedule days typically occur during times of inclement weather or around certain holidays. The decision to run an "S" schedule is typically made the evening prior, or very early in the morning, before service starts. Service updates are passed to our riders via Train Talk emails, website updates, Facebook, Twitter and alerts to local media outlets.