pnorman has commented on the following diary entries

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OpenStreetMap Isn't All That Open, Let's Change That and Drop Share-Alike 11 months ago

Yet, I think we may be able to get a long way with the ODbL. I think it at least worthwhile to share more details on possible legal interpretations. I remember at SotM-US last year, a productive BoF about licensing. Seemed to me like one question, geocoding into 3rd party databases, seemed close to a workable and widely supported realization. There was a lawyer who was interested and seemed to have some ideas about how it could work.

One of the points out of that session was that the companies involved with issues were going to provide to the LWG a clear description of their geocoding use case on which they were having issues, and this hasn't happened.

The Mucky Pup 11 months ago

With a vector PDF the glitches are laid bare a little more than web maps we're used to (Some would normally be lost in sub-pixel fluff) especially as I had scaled it up to fill the whole A4 sheet. Certainly printout made for some fun pub conversations.

When I did work on print rendering I found mapnik PDF rendering was worse than AGG rendering for text. I'm not sure if this has improved with recent versions, but I ended up doing 600 DPI PNGs and embedding them in a PDF.

Universal language about 1 year ago

Yes, let's all talk in Esperanto.

Attribution and all that (a rant) about 1 year ago

I do my best to attribute OpenStreetmap in my mobile app, one thing that is bothering me, however, is the requirement to make the logo clickable and it opens a webbrowser.

There is no such requirement. The attribution requirements for produced works are

You must include a notice associated with the Produced Work reasonably calculated to make any Person that uses, views, accesses, interacts with, or is otherwise exposed to the Produced Work aware that Content was obtained from [OpenStreetMap], and that it is available under [the ODbL].

Normally this is done with hyperlinks because that's by far the easiest way to meet the requirements in a medium where you can do hyperlinks, but if you've got one where it doesn't make sense, why not use plain text.

You could use the 4.3.a example notice from the ODbL, including the plain text of the URIs as suggested. This works out to "Contains information from, which is made available here under the Open Database License (ODbL) ("

Motivation for Contributing to OSM about 1 year ago

Comment from mgehling on 6 December 2013 at 17:05


Pardon? Please assume good faith and be careful before sending a message accusing a mapper of spam. Particularly in a case like this where the message isn't spam.

OpenStreetMap and the Public Domain about 1 year ago

Something worth noting is that with a public-domain database you are unable to use most government data. Most governments are releasing data under licenses that require attribution, which cannot be used as public domain data.

Reports about global administrative boundaries over 1 year ago

Note - do NOT upload GADM data to OpenStreetMap. It is not under a compatible license.

Land Use versus Residential Private Property over 1 year ago

There is actually a general consensus against the importing of property lot data into OSM.

Stuff like fences, hedges, etc get mapped and are verifiable, but these don't always correlate to property lots. Many times what you'd think was one lot when looking on the ground is really multiple ones. Then you get buildings that sit on multiple lots, etc.

CanVec Data over 1 year ago

Much of the CanVec water data in many regions is over 30 years old, I'd be bold in deleting it if you can't see any signs.

OSM datasize in PostGIS over 1 year ago

The big difference between osm2pgsql and pgsnapshot is osm2pgsql is lossy, so can disregard most of the tags.

The other tips are

  • Use --write-pgsql-dump and if you want geometry columns build them with osmosis. It's a more manual process but it is way faster.
  • If you need geometry columns and have the RAM, give java 32GB of heap space, otherwise put the node location store temp files on a SSD
  • When building indexes, omit any indexes you're not planning to use. If you're just performing tag analysis, you could get away with no geometry indexes, and the nodes geom index takes more time then loading the data.

For reference, creating and loading the dump files takes 10h51m on my home dev server and with decent sequential disk speed is CPU bound if you have in memory node store.

The --read-pbf-fast option with as many workers as CPU cores may help a bit here.

Small fix to osm2pgsql commited almost 2 years ago

I ran into a similar problem with addressmerge, except my addresses could be marginally outside the buildings. I solved it by adding a column in which I buffered the geometry with

UPDATE import_addresses SET buffered_geom = geometry(ST_Buffer(geography(geom),N));

where N was the distance, on the order of 1-2 meters (real meters, not mercator meters). For some purposes you might want to reproject but I was working in WGS84.

For mercator you could just use ST_Buffer and multiply N by a factor, but I had to do the reprojections.

Another trick for doing the JOINs between addresses and buildings was to pre-filter with && and then do ST_DWithin(geography(...), geography(...), N)

In my code this was expressed as

a LEFT JOIN b ON != AND ST_Expand(a.geom, PRECOMPUTED_DEGREES) && b.geom AND ST_DWithin(geography(a.geom), geography(b.geom), DISTANCE)

with PRECOMPUTED_DEGREES being DISTANCE * scale, where scale is chosen from the point closest to the pole in the region I'm considering.

New on OpenStreetMap almost 2 years ago

Always good to see more people from BC

pnorman, from Vancouver

South Fraser Perimeter Road - Surveyed about 2 years ago

On the SFPR or Port Mann?

On the SFPR I believe it's just a shoulder in the opened part. The lanes are wide and it's a decent smooth shoulder, so it's not too bad.

On the Port Mann I imagine they will be the last part to go in. This isn't solely because of a disregard for bikes, they're also in the last part to be constructed.

The SFPR is a good route for going from the Patullo to 176th/Barnston on a bike. The old route through Whalley, Gildford and Jhonson Heights involved a lot of stop lights, traffic and hills. The SFPR has fewer of all of these. There are no exits or stop lights on the part of the SFPR that's been constructed, there's just the ones off of the ends which aren't actually part of it.

New Lower Mainland Imagery sources about 2 years ago

Thanks - it should be fixed. Also there's a new layer in P2/JOSM by default, bc_mosaic. It's composed of the various layers stitched together into one layer which represents the "best" of the imagery.

Alaska / BC border is obviously messed up. about 2 years ago

I did some work with the BC/Washington State border some time ago using the IBC data

The IBC data is legally okay to use, so there's no worries there.

By far the biggest task on the border is de-duplicating the various ways. Simply put, the border is a mess. The position is relatively easy to fix once the duplicate ways are fixed and all the boundary relations are okay.

I've prepared .osm files for the SE Alaska and Portland parts of the border at

The best workflow I've found is to first clean up the border, making all of the boundary relations topologically consistent and then merge through point by point the turning points and monuments, merging existing nodes to them.

I'm currently working on SEAlaska.osm

I did not convert from NAD83 to WGS84 but this is in practice a non-issue as the differences are minimal.

Is this a redaction bug? over 2 years ago

For way 41789598 tags were added by Scocasso who didn't accept, so those tags have to be hidden.

For way 31158977 highway=residential was removed in v5 then added in v6.

For way 92818746 most of the nodes (e.g. appear to be from amai who didn't accept, so the nodes got deleted which required changing the way.

Ugg I screwed up over 2 years ago

Could you provide a link to the imports@ and talk-us@ mailing list discussion that happened before you started this upload? I can't seem to find it.

Added correct street names to Red Wing almost 3 years ago

Welcome to OSM. It's good to see another editor in BC. I'm based out of Vancouver myself.