Different pick up and drop off for FLEX

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MFDZ (HSLdevcom/)OpenTripPlanner clone supporting Carpooling.

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Different pick up and drop off for FLEX #101

Closed leonardehrenfried closed 3 years ago

leonardehrenfried commented 3 years ago

Gard has said in the OTP dev meeting that right now you can only have the same type of flex pick-up and drop-off in a single route.

However, in the Herrenberg case we have different pickup and drop off rules:

Pick up is only possible at the bus stop
Drop off is possible within 300m of a bus stop

leonardehrenfried commented 3 years ago

@derhuerst Are different pickup/dropoff rules, as described above, even possible in GTFS Flex?

leonardehrenfried commented 3 years ago

Ah, I checked stoptimes.txt and there are the columns pickup_rule_id and dropoff_rule_id. Presumably this means that it's possible, right?

derhuerst commented 3 years ago

GTFS-Flex v2 is split up into two parts:

GTFS-FlexibleTrips extends stop_times.txt to
- support pickup/drop-off areas (by referencing items in locations.geojson)
- support specifying a pickup/drop-off time window
GTFS-BookingRules extends the GTFS dataset to
- define rules on when and how to book

Both just extend GTFS-Static, which already supports separate pickup_type & drop_off_type, so yes, they do support having separate rules for pickup/drop-off.

flaktack commented 3 years ago

The conclusion at Thursday's meeting was that this could only be handled using GTFS by having duplicated stop times:

for pick up an actual Stop is included
for drop off a Location is included

And so every stop would be present twice:

bus station stop (drop_off_type=1)
bus station location (pickup_type=1)
...

leonardehrenfried commented 3 years ago

Do you mean with the current code or really conceptually only possible by having 2 stops?

flaktack commented 3 years ago

Conceptually -- I don't see how that could be modeled with a single stop time:

If a Location is referenced, how would you limit it to only pick up at the centerpoint, but allow drop off throughout the whole area?
- If a Stop is referenced, than how do you specify the area?

flaktack commented 3 years ago

A third option could be a LocationGroup, but there is still no option to differentiate between the elements (-> use the Stop for pickup, the StopLocation for drop off)

derhuerst commented 3 years ago

A third option could be a LocationGroup, but there is still no option to differentiate between the elements (-> use the Stop for pickup, the StopLocation for drop off)

For pickup, you can directly reference a stop from stops.txt. For drop-off, you can reference a location group (from location_groups.txt) that includes both the stop (from stops.txt) as well as the location/area (from locations.gejson).

Edit: My bad, you can't, there's only one stop_id in stop_times.txt.

leonardehrenfried commented 3 years ago

@hbruch It seems that we're at a conceptual dead-end here.

Unless someone has a better idea, I see the following options:

extend the Flex spec with our own custom modification - huge implications as we would need to modify OBA, too
make Herrenberg Bahnhof a fixed stop rather than a location with a radius

Can you advise?

leonardehrenfried commented 3 years ago

Closed in favour of https://github.com/derhuerst/generate-herrenberg-gtfs-flex/issues/5