[Talk-us] Fresno has no primary roads

Alan Mintz Alan_Mintz+OSM at Earthlink.Net
Wed Feb 15 09:09:20 GMT 2012


At 2012-02-13 15:21, you wrote:
>I've never been to Fresno, but I can't believe there would not be a
>single primary road there. Still, that is the Truth According To
>OSM[1]

I find that most areas where there has been little manual editing of the 
TIGER import will have roads that are generally under-classified (i.e. 
mostly highway=residential, with few if any higher-classed roads). I don't 
know where TIGER's original classifications came from, but they don't seem 
to match common sense very well or even documented sources, like city 
general plans.

FWIW, TIGER 2011 is no better, and getting even worse in some other 
respects, like naming errors.

...

A little research yielded this GP circulation map: 
http://www.fresno.gov/NR/rdonlyres/5EA02A61-FCDE-41C2-B707-DDED0E820677/0/GeneralPlancirculation.pdf 
(it's not clear if this "2025" map is projected or current - more 
research). It seems to have five classifications above residential/local 
(ignoring the "scenic" modifier), which I would map as follows:

Collector -> tertiary
Arterial -> secondary
Super Arterial -> primary
Expressway -> primary
Freeway -> motorway

Closer inspection of imagery or a survey might lead me to downgrade a 
motorway or upgrade a primary to trunk, based on features like on/offramps, 
etc. CA-99 used to have a lot of areas that were more trunk-like than 
freeway, but it looks like it's been built up to freeway standards in this 
area at least.

The Streets download listed here: 
http://www.fresno.gov/Government/DepartmentDirectory/InformationServices/GIS/Layers.htm 
has GPCIRC values which seems to correlate with the values shown in the map 
with a little work (I can't find a data dictionary, but the coordinate 
system seems to be CCS Zone 04, US Feet).





>Who knows more about this situation? Are there any local mappers on
>this list who can shed their light on this? Is this armchair mapping
>gone awry? Someone who doesn't like red?
>
>[1] http://www.openstreetmap.org/?lat=36.7974&lon=-119.7218&zoom=12&layers=M
>
>--
>martijn van exel
>geospatial omnivore
>1109 1st ave #2
>salt lake city, ut 84103
>801-550-5815
>http://oegeo.wordpress.com
>
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--
Alan Mintz <Alan_Mintz+OSM at Earthlink.net>




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