[postgis-devel] [PostGIS] #1052: Tiger Geocoder 2010 Geocode() "squishing" toward end of block

PostGIS trac at osgeo.org
Fri Oct 14 11:58:06 PDT 2011

#1052: Tiger Geocoder 2010 Geocode() "squishing" toward end of block
  Reporter:  mikepease       |       Owner:  robe         
      Type:  enhancement     |      Status:  reopened     
  Priority:  medium          |   Milestone:  PostGIS 2.0.0
 Component:  tiger geocoder  |     Version:  trunk        
Resolution:                  |    Keywords:               
Changes (by woodbri):

 * cc: woodbri (added)


 Hi All, I'm somewhat late to this thread but I can add a little to this.
 Tiger tends to round ranges up to 99-100 unless it overlaps with another
 range on an adjacent street, and it might do the rounding anyway because
 Census mandate to not uniquely identify any single response. This means
 you will get a general shift of address locations to the beginning of the
 segment as digitized. This probably accounts for the the north-south
 shifts you were seeing above.

 OSM imported all of Tiger in 2006 before the first Tiger shape files were
 released if I'm not mistaken. So all the test on 3253 32nd Ave S that
 ended in the middle of the street are probably based on Tiger data. Bing
 addresses are "Rooftop, Address" so they probably have parcel data that is
 augmented with road range data for rural areas. Google has acquired parcel
 data and they also collect street numbers as part of they street view data

 Tiger data is just broken! That said it is still great data for the cost,
 coverage, etc, but you have to understand these limitations.

 There was some discussion on another list (but I can not find it now)
 about trying to analyze the Tiger segments by looking at adjacent segment
 ranges to see if it was possible to modify the value in a reasonable way.
 At the same time it might be possible to populate street names on no name
 segments based on such an analysis. But this is getting into a whole other
 discussion and there are problems like how to you reapply this as
 subsequent Tiger releases come out.

Ticket URL: <http://trac.osgeo.org/postgis/ticket/1052#comment:22>
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