[Talk-us] georgia road classifications

[Kevin Samples]

Chris Lawrence wrote:
> On Wed, Sep 9, 2009 at 3:28 AM, Kevin <ksamples at uga.edu> wrote:
>   
>> I thought I'd bring this to the list before I got too far along.  I'd
>> like to class or reclass all the roads in Georgia according to the
>> Highway Functional Classification System
>> (http://www.fhwa.dot.gov/planning/fctoc.htm).  My source information is
>> from the Georgia DOT
>> (http://www.dot.state.ga.us/maps/Pages/HighwaySystem.aspx).  I've
>> searched a little about road classifications in the archives and found
>> one reference to this system
>> (http://www.nabble.com/Road-classification-td21036868.html#a21040315)
>> from December 08 and it seems to correspond to the United States
>> proposed alternative in the wiki
>> (http://wiki.openstreetmap.org/wiki/Highway).  What's the consensus or
>> is there one?  Does anyone see a problem with this or have an objection?
>>
>> my crosswalk to osm would be... [clipped]
>>     
>
> My biggest concern is that the functional classification system used
> by FHWA and state DOTs will under-classify some roads; non-Interstate
> freeways (e.g. GA 400, the US 78 Stone Mountain Freeway, etc.) are
> classified as either "Urban Freeways and Expressways" or "Rural
> Principal Arterials" yet are properly classified as highway:motorway
> in OSM.
>
> Also, I would be careful about automatically reclassifying any route
> that someone has already manually reclassified.  At a minimum, that
> would mean restricting automatic edits to tiger:reviewed=no ways,
> although I probably would be even more conservative (only
> reclassifying ways that were last edited by DaveHansen, e.g. as part
> of the TIGER upload; or, alternatively, only reclassifying ways where
> the current highway type is the same as the TIGER automatic remapping
> - compare tiger:cfcc tags with highway tags).
>
>
> Chris
>   
it looks like classifying "Urban Freeways and Expressways" as motorway 
is the way to go.  I double checked GA400, US78, and GA316 and they fall 
in the "Urban Freeways and Expressways" where they are exclusively 
limited access.  So after going back through the definitions from the 
FHWA documents, here is a revised crosswalk. let me know what you think....

Rural Interstate Principal Arterial - highway:motorway
Rural Principal Arterial - highway:trunk
Rural Minor Arterial - highway:primary
Rural Major Collector - highway:secondary
Rural Minor Collector - highway:tertiary
Rural Local Road - highway:residential
Urban Interstate Principal Arterial - highway:motorway
Urban Freeways and Expressways - highway:motorway
Urban Principal Arterial - highway:primary
Urban Minor Arterial - highway:secondary
Urban Collector Street - highway:tertiary
Urban Local Street - highway:residential

The process for doing this classification is in no way going to be 
automated.  This will be a 159 day manual project and I'll be sure to 
avoid screwing up anybody else's work.  By the way, I believe that all 
state DOT's are using the FHWA classification scheme.  just google 
"Functional Classification system".

Kevin