Allow to collapse platforms to a single stop for optimizing route graph #32
Description
Description
Many internal routes are created because every platform is represented as a unique GTFS station; since internal routes are generated to correspond to a unique sequence of stops it leads to many variations, making the graph more complex.
Proposed Solution
Offering an option to collapse routes and use only the parents would lead to significantly fewer routes and important memory and performance improvements. In this case, station-level transfer times should be inferred from trip level transfers at that station and used during the routing as an approximation. It most likely means that platform information should be included alongside the trip storage in routes to properly include platform information in the final route.
The solution should be generic and GTFS compliant and not rely on SBB ID formats to find parents.
Additional Context
OpenTripPlanner seems to implement a similar solution. SBB transfer times seem to be static within a given station in practice for now.