On Wed, 17 Jun 2015, Martijn van Exel wrote:
Hi Andrew,
Thanks for elaborating on the CanVec / Geobase imports! This also raises new
questions.. See below.
On Jun 17, 2015, at 3:00 PM, Andrew MacKinnon <andrew...@gmail.com> wrote:
A lot of the data in Canada was imported from CanVec and Geobase,
some of it by me several years ago. The imported data is pretty poor
quality in many places. I haven't done much work on this recently, as
imports have a bad reputation in OSM and I am mostly concerned with
surveying. For example:
- Some older road data comes from an import which combined CanVec and
Statistics Canada road names, attempting to match the road names in
Statistics Canada with roads without names from CanVec, and this data
is poor quality.
Is this described in more detail anywhere? Are the data / scripts /
process still available? Which dat was poor quality, CanVec or Statistics
Canada?
The StatsCan geometries were really poor at least as bad as the original
TIGER stuff but they were the only source of road names in some places.
The scripts used for the geobase->osm (and attaching statscan names) are
available at
http://svn.openstreetmap.org/applications/utils/import/geobase2osm
I only did this in Alberta and Ontario.
We tried to use roadmatcher to only include road segments that we were
pretty sure didn't already exist in OSM. This often left gaps in road
segments where roadmatcher wasn't sure if something was or wasn't included.
Also we didn't have any way of automatically attaching the existing OSM
ways with the new geobase ways which left A LOT of unconnected roads. This
has mostly been fixed (often thanks to keeprite and maproulette) but it
tooks many years.
Some of the initial sections also didn't connect new geobase roads with each
other due to a bug the import script, we tried to fix this with repair
scripts at the time.
Steve
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