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    <p>You could construct a directed graph (DAG) where each stop belonging to a route is a node and each transition between two stops in a trip is an edge. Then, you could perform a topological sorting of the graph (<a href="http://en.wikipedia.org/wiki/Topological_sorting" rel="nofollow">http://en.wikipedia.org/wiki/Topological_sorting</a>) to get an ordering of the stops. Note that topological sorting only works for graphs that have no cycles, but some trips do in fact have cycles, so you would not want to add an edge if it created a cycle.</p> <p>This happens to be the algorithm used by the OneBusAway application suite for ordering stops: <a href="https://github.com/OneBusAway/onebusaway-application-modules/blob/master/onebusaway-transit-data-federation/src/main/java/org/onebusaway/transit_data_federation/impl/beans/RouteBeanServiceImpl.java#L281" rel="nofollow">https://github.com/OneBusAway/onebusaway-application-modules/blob/master/onebusaway-transit-data-federation/src/main/java/org/onebusaway/transit_data_federation/impl/beans/RouteBeanServiceImpl.java#L281</a></p> <p>Note that sometimes routes will have forks or branches, where there are two sets of stops (one for each branch) that don't interact with each other. A naive topological sort might arbitrarily interleave these stops, but the OBA code uses the following two heuristics to get a more natural ordering:</p> <p>1) Group stops in the same branch together.</p> <p>2) When ordering two branches relative to each other, put the branch closer in distance to the branch point first.</p>
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    1. PODetermine correct GTFS stop order without using stop_sequence?
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    1. PODetermine correct GTFS stop order without using stop_sequence?
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    1. COI will try this and let you know how it goes. It's such a pain that all of this extra work is required when the people creating the GTFS feed could have just used the stop_sequence field more intelligently.
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    2. COI am not to sure if this will work since there only exists data on each transition from stop to stop if it's from the same trip. Therefore, there is no way for me to properly draw edges between stops from different trips. To relate this back to my example, there is no way for me to determine that `Stop C` should actually come before `Stop E` (at least not that I can figure out).
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    3. COAnd why exactly should stop C come before stop E (English alphabet aside)? Perhaps your route has a branch at the end, with half the buses going to C-D and the other half going to E. In such a situation is there really a "proper" ordering of stops?
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