[talk-au] Missing streets in Sydney

Steve Bennett stevagewp at gmail.com
Mon Sep 5 05:31:03 BST 2011

On Fri, Sep 2, 2011 at 10:40 AM, Ian Sergeant <inas66+osm at gmail.com> wrote:

Since you asked:

> One way streets?

Yep. A one-way street mapped as a two-way street is better than nothing.

>  Roads with barriers at the end of them?

It's highly unlikely that a truly impassable (by bike) street would be
incorrectly mapped from aerial imagery. By contrast, I've fixed, from
imagery, impassable roads that had previously been traced from out of
copyright maps.

 > Roads with no
> entry signs?

I'm happy to take my chances.

>  Cross country roads that are private and gated?

They make great stories.

>  Through roads
> mapped as service roads, and v.v?

Not sure why that would be a problem.

> The amount of incorrect names, roads, etc in other maps sources verges on
> the absurd.  In my local area I could point to tens of examples of streets
> on other maps sources with the wrong names.

Me too. I could also point to thousands of examples of streets with
the right name.

>  I'd like to think the survey
> and consequent accuracy is an integral part of OSM.

To me, accuracy is an aspirational goal, ranking somewhat lower than

> This tracing vs survey argument is as old as OSM is.  My vision of OSM is to
> get take a different route on the bike, or see more of a town when you are
> passing through, or even go for a walk around streets in your local area,

So your motivation for working on OSM is to get out and about? That's great.

> rather than being a mechanical turk in front of a computer screen, but each
> to their own.

Indeed. Criticising the contribution that myself and other aerial
tracers make for its inherent limitations is not really "to each their
own", though...

> Sometimes there is no alternative to tracing, but I think
> tracing without actually ever having placed a foot on the ground in the
> area, leads to a significantly poorer quality map, and you don't need to
> delve to far into the database for evidence of that..

Poorer than what? You need to be explicit about the comparison you're
making. This is volunteer labour, and you can't meaningfully compare
the contribution that people are willing to make against the
contribution you'd prefer they make. And if you want to, you have to
factor in time and other costs. I can trace 10 streets in the time you
can survey one. We could argue about which is the more valuable
contribution - or we could recognise that both are valuable, and get
back to it.


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