Since I'm the one who proposed this initially, I'm going to add some more
detail.

Stops on opposing sides of a street are hardly ever, exactly opposite one
another, so usually there are 2 stop_positions. This means there will
usually be pairs of route_segment relations, one for each direction.

For stops near a crossing, where some bus lines go to the right, others
straight on and others to the left, the (high)way up to the crossing can
become member of up to 6 relations. But that's still better than to have
them as members of all route relations and their variations for a line.

Having a route_segment for each sequence of highways between two stops, is
a possibility, but there I don't see a reason why a segment couldn't
describe how the bus goes from A to E passing B, C and D.

Unfortunately, one of the advantages of the Oxomoa scheme (being able to
oversee immediately that a route is continuous in the relation editor)
would be lost with the use of subrelations. This can be fixed, given
support is programmed for it in the relation editor (thinking mostly of
JOSM here).


The biggest advantage is that now it's the route_segments wich become
broken instead of. It's a lot easier to fix those segments once instead of
fixing tens of route relations which would otherwise be present on those
highways.

Lastly I want to add that in some cases (around bus stations which are
mapped in full detail for example), there would still be a need to add
(high)ways to the route relations themselves in some cases.

Polyglot


2013/12/26 <v...@freenet.de>

> Hi,
>
> i have read some mails about problems with too much relations for public
> transport lines.
> Also I see a problem with stoppoints and platforms specaly by bus and tram
> lines.
> And maintain with other Data maybe not very easy esp. GTFS data.
>
> In most systems I know there are stored segemts between two stops and
> these segments together are a lineroute.
> These segemnts, I think, have some advantages:
> - only one relation for each direction on the between most stops
> - no need for stoppoints because the relation starts and ends at a
> stoppoint near the platform
> - easy to ad new lines because the can use existing segments
> - most flexibility because small segments ( this may be a disadvantage too
> because it need much work at the start)
>
> regards Jan
>
>
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