2. Topics
• Origins and current state of New York data in OSM
• What needs to be fixed?
• Opportunities for import from external data sources
• Things to watch for when importing
• NY in OpenHistorical Map (OHM)
• NOT a tutorial
3. Current Data
• Major Sources
• TIGER
• USGS
• NYS DEC
• National Hydrography Dataset
• NYC DoIIT GIS Department
• New York Public Library
4. TIGER
• 2007
• OSM imported the 2005 TIGER road centerline data for
most of the US
• We have been dealing with the consequences of this
ever since
• Very early data import effort - we didn’t really know how
to do imports well at the time
• TIGER was in a state of transition at the time
6. TIGER Review
• Even “good” TIGER data can use some care and
attention
• Review process consists of verifying name, connectivity,
location, restrictions
• persistent low level error rate in Capital District
• often minor but still there
7. TIGER Review
• Outside of well mapped areas, work needed
• correcting poorly located roads in problem counties
• County Routes in Western NY not correctly classified
• long, slow process of TIGER review
• New, better TIGER exists, but conflation is easier to
say than it is to do
8. TIGER Review
• “Old” (2007)
TIGER in red
• Newer (2012)
TIGER in white
• Sample from
Schoharie
County
10. Administrative Boundaries
• Original State & County boundaries in OSM came from
USGS
• quality not great
• later import (2008) of City, Village, CDP boundaries from
TIGER
• not coordinated with previous USGS import, did not line
up well
• probably CDPs don’t actually belong in OSM
11. Administrative Boundaries
• Effort over the past several years to clean up boundary
mess using current TIGER boundaries
• add Town boundaries
• Hudson Valley complete
• Some work done towards Western NY
• NY/NJ borders substantially improved
14. Opportunities
• Big win if we can import building footprint and address
data statewide
• Needs to be done carefully, but the NYC import turned
out beautifully, proving that it can be done well
• Challenge: must be negotiated with individual data
owners across the state
• GIS Clearinghouse terms not compatible with
OpenStreetMap license terms
15. Imports
• Compatible license terms
• Restrictions on redistribution are deadly
• For example, CDTA bike racks can’t be imported due
to redistribution restrictions in license
• CC0 from Creative Commons works well
• PD equivalent
16. Imports
• Data quality
• many of the existing data sets are excellent, but some
are awful
• Respect local mappers
17. Imports
• Quality Control plan
• Control for recognizing trouble
• Plans for backing out if trouble happens
• Consult with import committee
18. OpenHistoricalMap
• Goal is to be the best completely out of date map in the
world
• OSM is trying to be current, OHM is a complement
• Use OpenStreetMap tools and schemes as much as
possible
20. OpenHistoricalMap
• NYPL looking at more complex historical GIS projects
possibly involving OSM and OHM
• Another potential NY project in OHM - historic wetlands
