[Talk-ca] OSM data quality in Canada

[Martijn van Exel]

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 <andrewpmk at 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?

> - Road data in some areas is missing entirely.

This is probably easy to visualize, but do you happen to know where / why?

> - The CanVec address data is low quality, and is often broken - e.g.
> on a tile boundary address ranges will be split in half, and comes
> from several different versions of CanVec.
> - Other CanVec layers such as woods, lakes and so on were imported in
> some areas but not others. Much of this data is low quality.

Was some sort of progress page kept so we could see where certain features were imported or not (yet)? Has a followup ever been considered to augment / fix these botched / low quality imports? 

> - Some road names have too many spaces e.g. "John Street" is "John
> Street". Some address ranges are like that as well.
> - lanes=-1 and surface=unpaved for roads that are really paved in Quebec.
> - Better quality municipal GIS datasets are now available in some
> cities like Toronto, Peel Region and York Region and if they are
> properly licensed, these should be used whenever possible. There
> generally are some minor errors in these datasets, but they are far
> better quality than CanVec/Geobase.

Ah, interesting. Is there already a list of these candidates or would it make sense to start one and look into proper licensing?

> 
> I really like the TO-FIX Tiger Delta layer at
> <http://osmlab.github.io/to-fix/#/task/tigerdelta> which matches TIGER
> data with OSM data and tries to find errors. It would helpful if a
> similar tool were created for Canada.

Obviously I am partial to MapRoulette, but sure, let me check it out, I am sure we can come up with something similar for Canada. What would the reference data be instead of TIGER?

Again, thanks for your insights, Andrew.

Martijn