[Talk-us] Arkansas state road data "Open The Data"

Mike N. niceman at att.net
Tue Aug 17 02:23:20 BST 2010

Learon Dalby gave a talk at US State of the Map regarding road centerline 
data.   For slides of the presentation, see


  My summary is that he has gathered each county's GIS data over a period of 
time and now has the entire state's data with a license (PD?) that allows 
importing into OSM.   I haven't looked in detail at the Arkansas TIGER data, 
but it was likely gathered before all roads had been assigned names. 
Possibly the TIGER geometry is not as good as the current data from the 
counties.   The proposal is

   1.)  Use the GIS road centerline data to replace untouched TIGER data in 
OSM across the state of Arkansas.
   2.)  Establish a system to allow updates to the multiple databases over 
time - not necessarily an automated 'sync operation', but a bidirectional 
feed of changes.   OSM changes within an area would be fed back to the state 
GIS, then on to the county GIS where they would decide to use it if 
applicable.    County changes would propagate back to OSM in the form of 
some type of change set that someone could review and apply to OSM data if 
applicable.    In OSM terms, this would include the edits that break a way 
into many smaller ways for bridges, speed limits, lane counts, traffic 
lights, surface, sidewalk attributes, public transportation routes, etc.

In the possibly similar case of Massachusetts,  I cannot tell from the wiki 
whether they used the state centerlines instead of TIGER, or if they had 
replaced TIGER with MASSGIS data.

   It is of utmost importance to preserve any roadways touched by a human 
mapper.     In AR, these roads consist of mostly Interstates and US highways 
that have been fixed up for proper routing and relations.  To a lesser 
extent, some edits are from the attack of the duplicate node bots near 
county borders.   I did a study for the state of Arkansas to determine how 
many roads have been touched so far:


  For purposes of this study, I have treated the Un-abbreviation bot edits 
as unedited, if version=2.   The Un-abbreviation bot can be run again later 
if necessary, or applied to the incoming AR GIS data before importing it.

   Note that there are 3 worksheet tabs on the bottom of the spreadsheet. 
There is one active mapper in the city of Little Rock; he has touched many 
roads as he has improved the map in that area.      Carl Anderson gave an 
excellent talk on their experience in importing county GIS data in some of 
the Atlanta region.     Based on his experience, it is unlikely that the 
entire process can be automated.  It will be some form of manually deleting 
the unedited TIGER ways, then stitching the AR GIS data to any existing 
edited roads.    Most roads have not been touched, so remote, unedited 
counties would import with less labor.  Any techniques used here could be 
applied to other states with PD road centerline data.

   This is the limit of my knowledge - I have no experience with the tools 
Carl mentioned that can assist with importing data into an existing system, 
and I haven't looked at the AR GIS data to see what other challenges may lie 
ahead.   So I'm passing the ball to the next data import enthusiast...


More information about the Talk-us mailing list