[Talk-transit] GTFS compatibility

[Roland Olbricht]

> But we are still in the thinking-about-this stage, haven't made any
>  decisions, and are looking for suggestions and comments (hence this
>  posting). 

Let me make a suggestion: instead of producing duplicates and leaving mappers 
with the frustrating task of tiding up, you could use JOSM to do a semi-
automatic import. JOSM will offer quite powerful and versatile editing 
capabilities to solve conflicts immediately. I've extended the Public 
Transport Plug-In to offer an experimental GTFS import (for stops only at the 
moment). The aim of this software is to avoid cluttering the database with 
duplicates and to maintain the data model as consistent as possible. At the 
moment, the stops as treated as bus stops, because I can't find a stop type in 
the GTFS specification.

Installation instructions:
- download JOSM: http://josm.openstreetmap.org
- Run with "java -jar josm-tested.jar"
- Open "Edit > Preferences > Plugins" and select "public_transport"
- Restart JOSM

I suggest the following workflow:
- Download an area to work on into JOSM
- Import the respective GTFS file (stops.txt) with the plug-in
- The plugin will pre-sort on load
- work through the nodes that remain "pending": mark a line in the dialogue, 
press "Enable" to add the node, the "Show" and "Mark" to center on the node. 
If you want to join it with an existing node, this 

What happens on load of stops.txt:
- Every stop that is outside the bounding box of the currently loaded area in 
JOSM will be set to state "outside"
- Every other stop that is more than 1000m away from any existing bus stop 
(recognized as "highway"="bus_stop") will be added to the map (state: "added")
- Every stop nearby existing bus stops is set to state "pending".

What you can do within the plugin:
- The button "Enable" adds all stops currently marked as lines in the dialogue
  as nodes with
  "highway"="bus_stop"
  "stop_id"=[stop_id]
  "name"=[stop_name]
  to the map.
- The button "Disable" removes the stops marked as lines from the map.
- The button "Catch" drags an existing, marked node on the map to the position
  of the imported stop and tags it as explained above. An existing name is
  preserved.
- The button "Join" does the same as "Catch", but the node remains at the
  position of the existing node.
- The buttons "Mark" and "Show" mark resp. show a stop (must be enabled) from
  the dialogue on the map. The button "Find" marks lines the dialogue that
  correspond to marked nodes in the map.

Possible extensions or modifications to make life easier:
- Use remote control and a server application to only detect those areas where
  conflicts exist.
- Reuse existing "stop_id"s to match imported stops there. This would greatly
  simplify later updates.
- Use other attributes from "stops.txt"
- Make the workflow smoother, e.g. use key shortcuts for sequences like
  "Enable", "Show", "Mark".
- do something with "agency.txt".
and of course any idea you might have.

Cheers,

Roland