[OSM-talk] addressing

Matt Amos zerebubuth at gmail.com
Tue Dec 9 11:32:46 GMT 2008


On Tue, Dec 9, 2008 at 11:48 AM, Frederik Ramm <frederik at remote.org> wrote:
>> An even better alternative would probably be to add the collected
>> street relation to the associatedStreet one, but I'm not sure there is
>> support for relations in relations in the api / editors
>
> Still my advice is not to use relations wherever there is an easier way.
> One set of address tags per address, nothing could be easier, no
> relations required.

of the three people i know who've tried out the karlsruhe schema, all
very experienced mappers, one added an incorrect addr:street tag which
did not match the name of the street it was supposed to. it turned out
that the street signs were punctuated differently at each end of the
street. this is common enough in the UK that i've seen it many times
and, if it sometimes bites experienced mappers, i expect it will bite
inexperienced mappers harder and more often.

lets say there are 30 houses along a street (all nodes) and the way
name needs to be changed (either because it really changed, or because
it was misspelled in the first place). if there is a relation for the
addressing, the user needs to alter the name tag on the way. if
addr:street is used, the user needs to further select all the houses,
check that all 30 nodes are present and all have the same addr:street
tag and update them.

this means at least 31 objects are updated, whereas only one needs be
updated for the relatedStreet relation.

furthermore: with the name-based relation, if the user deletes the
existing way and re-draws it with a different name, everything
silently breaks. with the relation method the user is informed that
that street is "in use", which (hopefully) will prevent accidental
breakage.

sure, editor support isn't 100% yet, but why re-create a poor-man's
relations with name-based references, when we already have "proper"
relations?

cheers,

matt




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