[Imports] [Imports-us] New Orleans: importing buildings and addresses

[Matt Toups]

On 10/22/2014 06:29 PM, Clifford Snow wrote:
>
> On Wed, Oct 22, 2014 at 4:01 PM, Johan C <osmned at gmail.com 
> <mailto:osmned at gmail.com>> wrote:
>
>     1. In OSM it's common either to attach addresses/poi's to single
>     building outlines (if the complete building with all floors has
>     one address/poi) or to have them as separate nodes. Depending on
>     local communities imports can either choose to attach nodes to
>     building outlines or to import them as single nodes. Two factors
>     can be important in that decision: 1) when the nola address data
>     contains information on the entrance of a building, because it's
>     located on or near the entrance, it would be a waste to throw away
>     that useful info by merging that address data to the building
>     outline without setting an entrance tag 2) you write that the nola
>     updates of building outlines have a different frequency than the
>     updates of addresses. Will merging address data to buildings make
>     the update process in OSM more difficult?
>
> I second Johan's recommendation. In Seattle we choose to add an 
> address to the building outline if only one address existed and add 
> addresses as nodes when there are multiple addresses inside the 
> outline. Personally I believe that at some point we will have 
> sidewalks/driveways that allow routing from door to door. Just having 
> an address node on the entry way may not be sufficient. For example, 
> when the door is next to a fence or other barrier.

I think what you are describing is exactly what I'm doing. Are you 
saying you regret how the Seattle addressing was done?

Unfortunately the address points from the city government are not nearly 
precise enough to provide useful information in the case where there is 
only one address per building. The points can be found anywhere in a 
building, and sometimes not even within the building footprint. My own 
home, which is a case of one building/one address, unfortunately has my 
address node fall outside the building footprint (and not near my 
entrance, but closer to my backyard). I will need to fix this manually. 
The address data is kind of noisy sometimes.

When there are two address nodes (in the common case of a duplex home), 
they are usually ordered correctly so their positions remain useful. 
(For example, the left side of a home has one number and the right has 
another number) So we keep both nodes.

There may be confusion caused because there is also a pathological case: 
sometimes there are multiple address points in the same exact location. 
That is what I described in my earlier response to Jason Remillard. I 
have tried to outline the logic here: 
https://wiki.openstreetmap.org/wiki/New_Orleans,_Louisiana/Building_Outlines_Import#How_it_works

I want to emphasize that this is a pathological case. I wish it didn't 
come up. I had to spend quite some time on the import code to deal with 
it. But I think the end result is good.

Thanks for your input,
Matt
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