The Timetable Comparator Service stores current and historical CIF timetable data and reports on the differences that occur each day.
The Timetable Comparator sits behind a RESTful API and offers two request types:
- Service Changes Request: retrieves updates for a single service, or a list of services, using a custom comparison range that may span multiple days.
- Daily Delta Request: retrieves a daily delta file showing the differences between two consecutive CIF timetable files.
The Timetable Comparator is built to fit into a larger product workflow that allows ticket holders to be notified if their travel plans are impacted by scheduling changes.
Product Scope
Notifying ticket holders of a change to their journey involves a series of steps, as illustrated below. The scope of this product is limited to the first step.
The Timetable Comparator reports on changes to fields within the CIF data that may impact a passenger’s journey. Fields that have limited or no impact on a passenger’s journey, such as train speed, power type, timing load, etc, are not reported on.
Timetable Stability Buffer
Sometimes when timetables are updated, they may receive several updates over several days. Usually this is to work around further scheduling issues or to further refine the recent updates. To prevent passengers from being notified too frequently of partially completed changes, a timetable stability buffer is used to ensure the timetable is stable before being reported as changed.
The following rules are applied within the Timetable Comparator Service:
- Any changes detected to a service that is 10 or less days from departure will be released via the Timetable Comparator Service immediately. I.e., no stability buffer will be applied.
- Any changes detected to a service that is 11 or more days from departure will be held onto until that service has had no further changes for 2 consecutive days. After 2 consecutive days of no further changes, all buffered changes to that service will be released.
These rules are configurable within the Timetable Comparator Service and are subject to change in the future.