An operating system for extra long urban trains.

An operating system (OS) for subways and other urban railways is presented. The system uses extra long trains (XLTs) that can protrude beyond both ends of the station platforms. No added infrastructure is needed;only more rolling stock. The system's only technological requirement is that the doors in different parts of each train, e.g. its cars, can be operated independently. The system can preserve the level of service and evenly fill with passengers all the cars of an XLT so no space is wasted. With sufficiently long trains, a railway's productivity can be more than doubled. The proposed OS has a train side and a passenger side. On the train side, it includes train organization and station-stopping protocols and on the passenger side a new information system that organizes passengers at the platforms as required by the train side protocols. These protocols specify the composition of each train and what it does at each station; i.e., whether it stops or not; how it aligns its doors along the platform; whether each door opens or not; and the set of destinations advertised by each open door. A general menu of train side protocols is presented, as well as a mathematical framework for their optimization and analysis. Numerous examples illustrating key concepts are also presented.