[OSM-talk] OSM and MapQuest [was Hurricane hits MapQuest]

Nathan Edgars II neroute2 at gmail.com
Tue Oct 5 08:42:23 BST 2010



Nic Roets wrote:
> 
> On Tue, Oct 5, 2010 at 2:00 AM, Shaun McDonald
> <shaun at shaunmcdonald.me.uk> wrote:
>> On 5 Oct 2010, at 00:38, Nic Roets wrote:
>>> The biggest problem I experience when searching with Nominatim for a
>>> street is that you need to guess the place name that *it* has chosen.
>>> For example, Hyperion Drive falls in a suburb (johannesburg North, I
>>> think). The suburb falls in a region and the region falls in a city.
>>> And the city falls in a province. Some of that information is already
>>> in OSM as administrative borders.
>>
>> Admin, town and city boundaries are in many ways hit and miss with
>> nominatim, however that is generally through a lack of osm data. Or
>> better said just having points, where it is difficult to estimate the
>> size. For example according to Nominatim Surrey covers most of London
>> http://nominatim.openstreetmap.org/details.php?place_id=559111 (Which it
>> doesn't really). By using Polygons for the boundaries in the osm data
>> instead of simple points, it will be more likely to give a more accurate
>> result.
>>
> 
> That's a nice visual presentation. I guess it's generated by Fortune's
> algorithm like Brian mentioned on dev.
> 
> The first problem with trying to get polygons for all places is that
> surveying them can be quite labourious, if not impossible.
> 

Polygons won't solve the whole problem. For example, I have an Orlando
address, yet I'm in unincorporated Orange County, outside the city limits.
Probably the only way is to find matches near the city center (node if
present, else polygon centroid) and sort by distance, after somehow
eliminating duplicates (streets split into multiple ways).

A couple examples:
Della Drive, Orlando, Florida: All the results come out as being in "Dr.
Phillips, Edgewood, Orange County, 32819, Florida, United States of
America". Dr. Phillips is correct (it's the neighborhood) but Edgewood is a
city with a polygon about 6 miles to the east.
Ruby Lake Road, Vineland, Florida: no results (despite Vineland having a
polygon that Ruby Lake Road is inside), nor with any other nearby cities or
unincorporated communities; only Ruby Lake Road, Orange County, Florida
seems to work
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