[Talk-us] State ref tags on ways: Use of unique ISO/ANSI/USPS 2-letter state codes in RELATIONS as well as WAYS?

[Minh Nguyen]

On 16:04 2014-03-11, Peter Davies wrote:
> I thought I would make my proposal stand out a bit more by adding words
> to the title.  :-O
>
> There are some weird things, like Nebraska's state law that requires
> NDOR to have a state road link to every community of a 100 people or
> more. I've changed some "Link 80F" ref tags to "NE 80F Link" and "Spur
> nnX" tags to "NE nnX Spur" without having time to do the whole state.
>
> AZ has its "Loop 101" and "Loop 202" freeways for which I would advocate
> refs "AZ Loop 101" and "AZ Loop 202".
>
> Texas also has many weird qualifiers on minor state routes but as I've
> never contracted there for 511 I'm not totally familiar with them.
>
> Peter

As others have mentioned, we already use unique two-letter state 
abbreviations as part of relations' network tags. I created a bunch of 
network=US:OH:LOG:Zane route relations last night (Zane Twp., Logan Co.) 
and I'm intent on keeping the ways' ref tags a bit shorter than that.

For all I know, Ohio's DOT could be an outlier, but they use "SR 123" 
notation exclusively, including on variable message signs [1] and at 
their traffic website OHGO [2].

I've firmly of the opinion that ways' ref tags should not always be 
considered uniquely identifiable. For something like a traffic reporting 
application, ways' ref tags should be at most a fallback in the absence 
of route relations. On the other hand, less qualified refs may be more 
useful in narrated directions: "Turn left at Link 80F" would be 
preferable to "Turn left at NE 80F Link." Why bother telling me what 
state I'm in as I approach the intersection?

It's unnecessary to cram more qualifiers and a rigid syntax into a 
single field when our data model has much more appropriate facilities 
for this information. Insisting on uniformity on ways' ref tags only 
invites data consumers to make poor assumptions. There's a CA 50 in 
Cantabria, Spain, after all. [3]

That said, I don't find a particularly strong case for leaving bare 
numbers in ways' ref tags. At least stevea's example of California 
county routes does already include a network identifier (the "G" in "G2").

[1] 
https://www.dot.state.oh.us/Divisions/Operations/Traffic/FAQs/PublishingImages/DMS_Carillon.jpg
[2] http://www.ohgo.com/
[3] http://osm.org/way/4843509#layers=Q

-- 
minh at nguyen.cincinnati.oh.us