[Talk-us] [josm-dev] Relation editor support for north/south and east/west similar to forward/backward

[Martijn van Exel]

On Wed, Nov 27, 2013 at 4:24 AM, SomeoneElse
<lists at mail.atownsend.org.uk> wrote:
> For example, imagine I'm near 2 ways that are both part of the I-80[1].  For
> simplicity let's assume that the way that I would take to get to eastbound
> destinations actually goes in an eastbound direction at my location.
>
> If it's important to recognise that there are two signed I-80 routes, one
> eastbound and one westbound, shouldn't there actually be two I-80 relations?
> The "eastboundness" is really a property of the route, rather than the
> individual way.

-josm-dev, adding talk-us

That's a great point, Andy. We have considered this and it's an
elegant solution. Just off the top of my head there's three
considerations that make this a less desirable option:
1) Some routes actually change signposted cardinal directions
(examples are some beltways) which would make for convoluted relation
hierarchies.
2) You would need to duplicate relations for single-carriageway numbered routes.
3) The member role approach is already widely established in the U.S.

Point 2) could be taken care of if we would make sure the member ways
all point in the same direction and just assign the signposted
cardinal direction to match the way direction, and infer the opposite
cardinal direction.
-- 
Martijn van Exel
http://oegeo.wordpress.com/
http://openstreetmap.us/