[Talk-transit] Naming concepts

[Stephen Sprunk]

On 2016-11-01 06:12, Felix Delattre wrote:
> On 31/10/16 19:05, Stephen Sprunk wrote:
>> For those not familiar with Transmodel, can you either explain what
>> its terms are for the concepts in question and/or point us to
>> resources that do?
> 
> I found this PDF on transmodel's definitions and concepts useful:
> http://transmodel-cen.eu/wp-content/uploads/2015/02/TRM6_Glossary-Part-123.pdf

That'll take a while to digest fully, but it appears your excerpt covers 
the current topic succinctly.  Thanks!

> * LINE: A group of ROUTEs which is generally known to the public by a
> similar name or number
> * ROUTE: An ordered list of located POINTs defining one single path
> through the road (or rail) network. A ROUTE may pass through the same
> POINT more than once.

I take it as a good sign that those are roughly the same terms/ideas 
that we collectively came up with off the cuff.  It's also good that 
they're ones a layman can fairly easily understand.  Unfortunately, both 
end here.

> * JOURNEY PATTERN: An ordered list of SCHEDULED STOP POINTs and TIMING
> POINTs on a single ROUTE, describing the pattern of working for public
> transport vehicles.A JOURNEY PATTERN may pass through the same POINT
> more than once. The first point of a JOURNEY PATTERN is the origin. The
> last point is the destination.

OSM: This seems to be (very) roughly equivalent to the set of 
stop_positions in a given route.  Without an additional formal level of 
abstraction, journey patterns along the same route have to duplicate the 
correct subset of ways in addition to the stop_positions.  I recognized 
that as frustrating when I did the rail lines here but I couldn't put my 
finger on exactly why at the time.

GTFS: This sounds like a shape, but it's optional and most agencies 
don't seem to bother, which means you have to compare the full list of 
stops to determine if two trips are using the same pattern.  But lazy 
agencies would probably give up entirely if they had to create/provide 
shapes, so I get it.

> * VEHICE JOURNEY: The planned movement of a public transport vehicle on
> a DAY TYPE from the start point to the end point of a JOURNEY PATTERN 
> on
> a specified ROUTE.

OSM: If schedule information is out of scope, I don't see a need/use for 
an equivalent to this.  (Not an argument either way, just a 
consequence.)

GTFS: This sounds like a trip.

S

-- 
Stephen Sprunk      "Those people who think they know everything
CCIE #3723         are a great annoyance to those of us who do."
K5SSS                                             --Isaac Asimov