OpenStreetMap
I just started working on cleaning up the map around Lakewood, California. The ways are tagged as being from TIGER/Line (United States Census Bureau data) but they are all running at odd angles and have junctions and curves where none exist.
I have been straightening the street, smoothing the curves, and marking important locations around the city (e.g. libraries, post offices, police and fire stations, etc.) The freeway on and off ramps are especially disasterous. Those are taking a lot of work. Some of the major streets have two or even three ways marking them and they are tagged as primary, secondary and residential. It should be much more pretty when I am done. : )
Discussion
Comment from daveemtb on 18 September 2008 at 11:18
As I understand it, the Tiger data is of extremely variable quality, as it's put together from a lot of different sources. It's great to see people turning it into good data :) Where things are a long way off, some of the duplicates may come from people adding streets they believe to be missing, when in fact they are just in the wrong place.