[Talk-scotland] Edinburgh - Belgrave Terrace/Clermiston Terrace

Eric Grosso eric.grosso.os at gmail.com
Tue Oct 6 16:58:11 UTC 2015


On 6 October 2015 at 15:43, Gregory (LivingWithDragons) <
info at livingwithdragons.com> wrote:

> Ah, I wasn't aware of name:left, name:right being used.
>
> While waiting for a good solution, a lot of people (myself included)
> mapped sections of pavement/sidewalk alongside the road. Such as this
> example of Anchorage Terrace in Durham.
> http://www.openstreetmap.org/way/23400852#map=19/54.77049/-1.57222
>

 The name:right/name:left works well now but it can lead to some minor
errors in the results provided by Nominatim , e.g. if you search for "1
Cadzow Place, Edinburgh", you'll have 3 results:
- the shop in "1 Cadzow Place, Edinburgh",
- the house number located at the door in "1 Cadzow Place, Edinburgh",
- the house number located at the door in "1 Earlston Place, Edinburgh", on
the other side of the street (here the street has 3 names: the main one is
London road, the right one is Cadzow Place and the left one is Earlston
Place).

Using the addok geocoder developed by Yohan Boniface (
https://github.com/etalab/addok) will lead to a good result (you can even
choose if you want or not include the shops in the results).



> That has the benefit of visually showing the name, but visuals should not
> be a mapper's main drive. You'll notice the Anchorage Terrace path is also
> a member of the Anchorage Terrace relation. Associated Street relations are
> great, you can look at them and find all the houses that are part of the
> street, even if they are round the corner. In reverse, if you search for "4
> Anchorage Terrace" then Nominatim finds it.
> http://wiki.openstreetmap.org/wiki/Relation:associatedStreet
>

You're right, this is a possibility but is it really needed now? Here are 3
reasons why we didn't implement these relations in Edinburgh (I talked here
on behalf of the MESH project not for the entire local OSM community):
- it's quite time consuming and not necessarily easy to manage and update
on the long term,
- it isn't necessarily easy to understand by new mappers,
- the current tools propose to find very quickly all associated numbers for
a street, e.g. http://overpass-turbo.eu/s/bRH

For info, Nominatim finds the "4 Anchorage Terrace" not because of the
"associatiedStreet" relation but because the "4 Anchorage Terrace" is
mapped as a house number and street on top of the building, and because the
"Anchorage Terrace" street exists. If you remove this "virtual" street,
Nominatim will not provide any results except if you add "Anchorage
Terrace" as a right, left or alt name for Church street on this section.
The addok geocoder will provide a result in any of the previous cases.

Cheers,
Eric
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