The S-train system: Synchronized express & local trains for urban commuter rail systems

Current urban commuter rail systems, especially subway systems, are not optimized to convey passengers at fast travel time, resulting in passenger crowding, delays, and congestion. Synchronous operation of express and local trains is desired to improve the systems. We propose the synchronized express and local system, the S-train System, to optimize urban commuter rail systems by minimizing passenger travel time and transfer delays at stations. The proposed S-train optimal commuter rail system optimizes traffic flow by achieving faster travel time and capacity increase using fewer trains, benefitting both passengers and the commuter rail system operators.