[Talk-us] Highway Tagging Consensus to Improve OSM (and address some of 41 latitude's concerns)
peterb at gatech.edu
Tue Oct 26 03:26:39 BST 2010
"Craig Hinners" <craig at hinnerspace.com> writes:
>> > On 10/15/2010 09:44 PM, Richard Welty wrote:
>> > Sans prefices, the highway=motorway where US Highway 10, Wisconsin Highway
>> > 66, and Interstate Highway 39 run together would have ref=10;66;39. Not
>> > very useful for determining which is which.
> This is why I keep arguing for using *non-ambiguous tag names*: the
> "what" should go in the tag name, and the "which" should go in the tag
> value. So, instead of the current situation where we have half a
> bazillion ways with a "network" tag name, you'd have:
> network:country[US]:unitedStatesHighway = 10
> network:country[US]:state[WI] = 66
> network:country[US]:interstate = 39
> (Or, if you're of the brevity and ambiguity trumps verbosity and clarity
> camp, I give you "network:US:WI", "network:US:US", "network:US:I".)
> Point being, by making a clean separation between the "what" and the
> "which", it makes it easier from the standpoint of an automated agent of
> OSM data, be it a renderer or whatnot: you have a clean query on the tag
> /name/ to get all routes of a certain classification (the "what"),
> regardless of /which/ route number it is.
> No endless parsing of the tag value, looking for "I-" to determine
> whether that way is an interstate, oh, oops, this guy doesn't like
> hyphens, I need to look for "I*", oh, oops, that gets me everything for
> Iowa and Idaho, oops, now my function to determine whether a way is an
> interstate is 10000 lines long with 500 "if" statements and regular
> expressions that would make a CS major run for the hills.
> No, none of that. Simply: if tag name =
> "network:country[US]:interstate", render the AASHTO shield with the
> number(s) in the tag value. Easy peesy.
> No arguing about relations, super relations, super duper relations,
> relations of relations of relations of sub-relations, orphan relations,
> bastard relations, divorced relations, etc. You just tag the ways with
> these non-ambiguous tag names. Relations are WTFs of complete and utter
"No endless parsing of the tag value"? No, instead we'd have endless
parsing of the tag name instead.
As a famous professor once told me, strings are the ultimate vehicle for
hiding information. You can never tell if a string is correct without a
complete string parser... it's like developing a whole new language from
I'm sorry, but I don't see how this is a better solution than relations.
With relations, a single well-defined first-level entity contains all
the information about which ways make up a road. That entity contains
its name, number, category (interstate, US highway, etc), and
Pushing this information onto tags on each of the ways makes this
information MUCH harder to find, from a querying point of view.
Requiring string parsing (instead of string matching) to complete
ordinary queries should not be encouraged. (IMO it's bad enough that we
have name, name_1, name_2, etc.)
Peter Budny \
Georgia Tech \
CS PhD student \
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