[Talk-us] State ref tags on ways

[Richard Weait]

"* the ref= on relations only contains the number. Any data consumer
composes the full route shield / name from the network and the ref
tags."

Almost. :-)  ref= contains the specific identifier of the route.
where I-35 splits into I-35E and I-35W (in two different states!) the
ref= should be 35E or 35W

This is one of those edge cases that we love so much in the road system.

I've been thinking of it this way.  "Network describes the shield. Ref
describes the printing on the shield." Now, that ain't right and that
is too close to tagging for the renderer, but it's how I keep it clear
in my mind.  And it's how I got my first shield renderer to work as
well as it did.* It was also designed to degrade well.  A renderer
like the old style lozenge markers would at least get the text right
by putting ref= in the lozenge.

Similar edge cases exist in US routes and State routes,

- the concurrency of US1 and US 9, where ref=1-9 isn't numeric, but is
right. http://en.wikipedia.org/wiki/U.S._Route_1/9

- New York State Route 3A where ref=3A and other alphanumeric routes.
http://en.wikipedia.org/wiki/New_York_State_Route_3A

I'm inclined to extend network to include banners, but worry that the
ordering of alt, business, truck, loop, spur, whatever, is not
obvious. And where do banners like Future fit in with those?  I'd hope
that we can make sense of the banners in a way that mappers don't need
a PhD. in tagging to improve their local data. network:banner=
perhaps? Or binary flags network:banner:alt=yes
network:banner:truck=yes ?

* which was 'as well as it worked, for some value of well'