[OSM-newbies] Locking tags is it possible?

[john whelan]

In Ottawa we started with few GPS traces and some satellite image mapping
for the major roads.  Then we back filled with CANVEC data.  What I've seen
is we protected the existing data by having a buffer round the existing
roads.  So we ended up with all road junctions onto the major road being
replaced by dead ends on the side roads and it looks as if you can't reach
the side roads from the major roads.  As time goes by this is being
corrected.  Some of the satellite mapping has lined up the wrong roads so
the junction is 100 meters out.  Having seen this type of problem I suspect
that there will be other instances of this type of error within the data.

To process the data tags by program you need consistency we don't have that
either in the tags or in the road names.  I'll use "Promenade Merkley Drive"
as an example.  That what is says on the street sign.  In some cases streets
in OpenStreetMap will be labeled "Merkley", or "Merkley Drive" or "Promenade
Merkley" or "Promenade Merkley Drive".  Programs are much better at finding
a match when the tag says "Merkley Drive" and the search term says "Merkley
Drive".  They aren't so good at matching "Promenade Merkley" with the search
term "Merkley Drive" and these apps are all about doing this stuff on the
tags and a program being able to recognise the terms.

The CANVEC data is at least consistent with itself.  Side roads meet main
roads etc and the roads are named in a consistent way.

Using it to load a "private" OSM server at least gives me something to put
up against Google.  Basically the quality of the Ottawa road data in OSM is
such that its unusable for processing by applications and if I suggested it
I think I'd just get laughed at.  It maybe decided to go with a cheaper
option of doing it all with OSM but that then becomes a cost issue not a
technical issue.

I think the POIs though for the most part have been entered by people on the
ground and are of higher quality, these I think we could probably import,
filtering out anything that said highway.  This can be refined a bit to
include footpaths etc.

Thanks for the input.

Cheerio John

On 30 April 2010 08:43, John F. Eldredge <john at jfeldredge.com> wrote:

> You will likely find some errors or out-of-date information in the road
> data, however.  For example, most of the road data here in Nashville,
> Tennessee, USA came from the TIGER import (created by the US Census).  Among
> the errors I have corrected are segments of a major road being labeled with
> the name of a road in a different part of the city (while other segments of
> the same road were correctly labeled); and two streets being shown as dead
> ends, even though they were connected to each other over 20 years ago.
>
> --
> John F. Eldredge -- john at jfeldredge.com
> "Reserve your right to think, for even to think wrongly is better than not
> to think at all." -- Hypatia of Alexandria
>
> -----Original Message-----
> From: john whelan <jwhelan0112 at gmail.com>
> Date: Thu, 29 Apr 2010 22:34:44
> To: <newbies at openstreetmap.org>
> Subject: Re: [OSM-newbies] Locking tags is it possible?
>
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