[Talk-transit] GTFS, tools and pt tags generally

Roland Olbricht roland.olbricht at gmx.de
Mon Jun 20 07:07:16 UTC 2016

Dear fellow mappers,

> Is anyone interested in updating these tools?  I can provide lots of
> input and testing, but my Java skills aren't where they need to be to
> attempt this alone.

I'm the author of the public_transport plugin. I would be interested in 
restarting development. It's not about Java skills, the problem is 
missing consent about tagging or, more precise, the general modelling.

There had been a group that was very vocal for making a textbook example 
of design by committee, and the result is now known as "approved public 
transport scheme". They did not ask for input from experienced mappers 
or developers. I decided to consider it a waste of time and stopped 

I'm not the only one. Tagging never really got traction, and only a tiny 
fraction of stops conforms to that approach. This is why we have now the 
mess we have.

One example is the dissent on whether the bus stop should be a node on 
the vehicle's way or a node where the passengers wait. You will find all 
solutions implemented, because each local community decided different. 
The "approved scheme" will allow any variant. It's even worse for where 
to put the name: I got even within local communities incompatible 
answers, all referring to the "approved scheme".

Another example are route relations. While there are wild constructions 
called route_master and network which are basically collection 
relations, the problem that bothers most people in practice has never 
been tackled: We would like to see per way segment only one or very few 
relations and need a construction to assemble itineraries from that. 
That would greatly reduce maintenance. And: how to tell apart services 
that run a few times per day from those that have a headway of a few 

Given that, it would help have an algorithm to answer the simple 
questions for real world examples and their current tagging:
- Where to start/end routing of passengers?
- Where to start/end routing of vehicles?
- How to obtain a name of a station?
There are probably more interesting questions. But it will be already 
hard enough to tell apart unusual tagging on purpose (because of a 
special situation) from mistakes and the various variants of taggings 
for these three, and adding complexity (like more questions) had killed 
a lot of prospective efforts.

It's not enough if the solution works fine in your local area and 
hopefully works somewhere else, more or less untested. We need an 
algorithm to do the right thing in 95% or better 99% of all places 
around the world.

> Is this the right list to discuss mass edits to add the missing tags, or would it be
> local lists for each area, or somewhere else?

Note that the hard thing isn't to write a bot that processes a lot of 
objects. The hard thing is tell what we actually want. The bot has to 
answer the above mentioned questions to actually do more good than harm.

To make it clear: We need rules how to understand what we have right 
now, changing at most 1% of all stops and stations or even less. Such a 
change we inevitably need local knowledge, hence it is unlikely that a 
bot will help. What we don't need is yet another standard.

Best regards,


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