Introduction - plannerstack/PTDS.js GitHub Wiki

Public Transport timetables are implicit graphs, it means that the system contains several parallel chains that are implicitly ordered. We can identify layers above and below schedules that form additional interdependence. The network is shared for all vehicle journeys, hence if one route over the road is affected it will affect all trips that share the same problematic route link. Similar interdependence exists for blocks, the combination of vehicle journeys operated by the same vehicle, if a vehicle journey earlier in the block was delayed, the vehicle journeys following might be affected. Duties, the flow how drivers move over vehicle journeys, is also affected by earlier decisions. From a more physical perspective a rail infrastructure is deterministic: vehicles have a limited options to overtake. Therefore, many if not all, effects happen in cascade, but have been never visualized. Nor does tooling exist to predict, or simulate, the effect of a decision. This projects paves the path for the ultimate goal: evaluating the best short term optimisation resulting in a solution for the deviation, minimizing the effort to operate.