[Talk-us] Admin boundaries tied to roads

[Alan Mintz]

At 2010-04-22 13:09, andrzej zaborowski wrote:
 >On 22 April 2010 04:24, Alan Mintz <Alan_Mintz+OSM at earthlink.net> wrote:
 >> At 2010-04-21 17:12, andrzej zaborowski wrote:
 >>>On 22 April 2010 01:18, Apollinaris Schoell <aschoell at gmail.com> wrote:
 >>> > On Wed, Apr 21, 2010 at 3:36 PM, andrzej zaborowski <balrogg at gmail.com>
 >>> > wrote:
 >>> >> Where's damage in that -- is it in that you can now read the name out
 >>> >> without checking the documentation for what that funny string means in
 >>> >> that particular database that is TIGER?
 >>
 >> I just had a machine crash as I was trying to find stats, but I'll bet that
 >> at least 90% of the cases are "St", "Ave"/"Av", and "Blvd"/"Bl", with the
 >> occasional "Ln" and "Cir"/"Cr" thrown in. When there's a lone N, S, E, or W
 >> as a prefix to a street name, it's clear to everyone what that means. These
 >> are the same abbreviations that _everyone_ uses every day - children,
 >> adults, businesses, governments, etc.
 >
 >Well, you just gave examples of the obvious ones, I'm not claiming any of 
these are not known.  But the list has 672 different forms.

My point, though, was that we were going to a lot of trouble for a small 
percentage of real-world cases that _might_ (see below) present a problem 
for someone to understand.


 >(but even the easy ones are hard for non-human consumers because St has 
at least three possible meanings, all three quite popular across the db).

I'm sorry, but as a suffix (i.e. for the regex / St$/), what else does St 
mean but Street?


 >> And I will do so again. My problem is mostly that this was done without a
 >> safety net. You clobbered existing data with no easy way to "walk it 
back"...
 >
 >Well, the way to "walk it back" is pretty easy, all the names can be 
taken from version-1 or reassembled from the tiger tags, so no worries there.

This doesn't work for streets that were edited by users. Again, my problem 
is that, in thousands of edits, I specifically only expanded, for example, 
the prefix "N" to "North" when it is logically part of the root name. When 
it is logically a housenumber suffix, as it is in the majority of southern 
CA, I left the prefix alone. The road name may have been otherwise edited, 
though (to correct spelling, rename completely, etc.) This was to be used 
in the future when we could agree on a way to correctly separate these 
component parts of the name, as they are and must be in any database to be 
used with routing and street addressing in the real world. To "walk it 
back", we will have to query the history of the way and find the version 
before the bot, to see what was done. It's not just v1, or TIGER, because 
it may have been otherwise edited. It's not even v[last-1] any more because 
there may have been other edits since the bot (I've done many myself).


 >>>...Then TIGER also includes Spanish names and the
 >>>list has abbreviations for those too, which rarely anyone in US can
 >>>read, while they can cope with unabbreviated ok.
 >>
 >> I don't agree. Much of the US speaks Spanish. Many more possess the
 >> tremendous brainpower and enoUGH grade-school Spanish required to know that
 >> Cl. in front of a street name might mean Calle or Cam. might mean Camino,
 >> or that S means Sur and N means Norte.
 >
 >But do you remember the 600 abbreviations used in tiger?  It's neither 
practical or useful or helps anyone, they're much like numerical 
codes.  The one single thing they may be good for is for rendering at lower 
zoom levels.

I don't understand. Why do I have to remember them? Am I not capable of 
inferring their meaning? Do I have to infer anything anyway, since they are 
likely to be similar/identical to signage? Also, to me "lower zoom levels" 
is almost any level at which I want to see a map. Anything more than a 
small neighborhood, and it's all we can do just to fit the root of the name 
in - we don't need any _more_ characters.


 >> name: The pre-balrog name
 >
 >99% percent of the cases this was an arbitrary version of name, taken 
from a database which was chosen only on the basis of its license, not 
because it was more correct or anything.  So I don't see any reason to hang 
on to it.

If I understand you correctly, I disagree completely. In my experience in 
southern CA, >90% of the time, TIGER is correct with the exception of the 
presence of the directional prefix. The real problem was the geometry[1].


 >> In the Los Angeles area, I rarely saw expanded names (which is why I
 >> continue to abbreviate), except for those rare instances where someone drew
 >> a street from scratch before TIGER (apparently), and not even all of those.

BTW, from my previously cited data chunk (35988 unique names in about 4400 
sq mi (11000 sq km) of southern CA) , I can now say that only ~0.2% of 
suffixes were present in their expanded form (i.e. Street, Avenue, etc.).


 >>>You could surely change the wiki but it's a conclusion that a lot of
 >>>people individually seem to come to so I'm sure you wouldn't even need
 >>>a bot before someone would add a phrase to that effect.
 >>
 >> I don't know about "a lot". I mostly just hear people regurgitate the
 >> "don't abbreviate" mantra without justification. Admittedly, maybe it's
 >> because it's already been hashed out to death and I'm late to the party.
 >> Regardless, maybe I'm not alone, and it deserves some re-thinking.
 >>
 >> Do people that are actually mapping (not bulk-importers) really want to
 >> type in "North Martin Luther King, Junior Boulevard Southwest" and then
 >> proofread that to make sure they didn't typo anything?
 >
 >It completely depends on what quality they expect from the resulting 
map.. Same way you could argue that if a road is zigzagging then people 
should map it as straight because it takes fewer clicks and at the same 
time you're not affected by your GPS inaccuracies... but it's a shortcut.

I don't accept that there is any loss of accuracy, unlike the zigzag 
example, for reasons stated above.



[1]It's too bad that it took them until TIGER09 to get accurate geometry. 
Is anyone working on any sort of "fix totally unedited TIGER07 ways from 
TIGER09" bot? I did a little work, converting chunks to KML, to see how 
accurate it was, but never went further.

--
Alan Mintz <Alan_Mintz+OSM at Earthlink.net>