[OSM-talk] OSM TIGER-based map quality

[Jonathan W. Lowe]

When overlaying OSM with the recently available TIGER 2007 shapefile
data for Census Blocks in Alameda County (California), I'm encountering
both an offset and difference in relative position of the linework.  In
short, OSM's data looks a lot more accurate and consistent -- streets
that should be straight actually look straight in OSM, but often zig-zag
in the TIGER 2007 edges and tabblock shapefiles.  For a visual, visit:
http://www.giswebsite.com/demos/tiger_overlays.html

Any observations or ideas about where the misalignment might come from?
Though it smells partially like a datum problem, that path hasn't
yielded any solutions yet.

Thanks,
Jonathan