[Talk-ca] Users in Ottawa and Geobase

[James A. Treacy]

On Tue, Oct 27, 2009 at 09:22:00PM -0400, john whelan wrote:
> Is there any way to get some consensus amongst OSM mappers in Ottawa
> to start clean again with just Geobase data?  How does one locate them
> or make a reasonable effort to locate them?  Or to reassure me that
> most of Ottawa is based on GPS and it's just sheer bad luck that my
> quality samples have hit the only two areas of bad data in the city.

There are a few areas in Canada that have had some top notch
mappers enter quite a bit of data before the geobase road data
became available. I suspect that a high percentage of those people
participate on talk-ca. For many reasons, it would be a bad idea to
replace that data using geobase and these people voiced that opinion
on talk-ca.

On the other hand, there are many areas that have had the occasional,
inexperienced mapper enter a few roads. These are generally of low
quality and make a mess of the geobase import. These people are not
on talk-ca so never had a chance to say, 'replace my work as it is
of dubious quality.' Fixing the roads can be a lot of work in this
case. Much more than simply replacing the work and then fixing a few
modified intersections and moving some roads using data from gps
traces.

In spite of the second case, anyone asking about poor quality roads is
given the party line that the existing work should stay.

This is ridiculous. 

When a situation arises that it is much more work to fix the roads
than to replace them outright from geobase I say blow away the
existing work and go with geobase.

Of course, some caution is required. Some guidelines before doing
wholesale removal of existing work:

- have at least a few weeks experience mapping
- don't consider starting the work unless you are willing to spend
  quite a bit of time cleaning up the map (a big one is tying into
  the surrounding roads).
- contact as many of the original mappers as you can find
- send mail to talk-ca giving reasons for wanting to do a replacement
- wait a week
- finally, send a mail to talk-ca stating your intention to start

-- 
James Treacy
treacy at debian.org