Peter Dobratz has commented on the following diary entries

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Mapping North Andover, MA 3 months ago

Hi and welcome!

Thanks for improving the map. There's always more that can be done.

If you want to coordinate with others in your area, there's an email list:

Getting addresses from the land parcels works very well when there is only 1 building in the parcel, but watch out for duplexes and other buildings with more than one address.

Cheers, Peter

Strange OSM Sighting over 1 year ago

I've stumbled across a number of companies using OSM data. I too assumed that their employees would have added the business and maybe some other surrounding things to the map, but that's often not the case.

house numbers with a leading zero almost 3 years ago

I think the whole situation is unusually confusing. I'm not sure about the exact methodology for determining house numbers, but it seems like in many cases "repeats" are avoided by cleverly selecting the numbers. However, there are a number of addresses that only differ by the presence or absence of a leading zero. Here is the list of such addresses that I've found so far:

  • 10 SW Custer St and 010 SW Custer St
  • 202 SW Custer St and 0202 SW Custer St
  • 220 SW Custer St and 0220 SW Custer St
  • 222 SW California St and 0222 SW California St
  • 15 SW Bancroft St and 015 SW Bancroft St
  • 25 SW Curry St and 025 SW Curry St
  • 16 SW Whitaker St and 016 SW Whitaker St
  • 17 SW Whitaker St and 017 SW Whitaker St
  • 24 SW Whitaker St and 024 SW Whitaker St
  • 117 SW Whitaker St and 0117 SW Whitaker St

I would imagine it would be quite confusing for people unfamiliar with the area to navigate to these places.

List of my changeset discussions? almost 3 years ago

Yes, it looks like there's no way to directly get this from the API now without looping through all the changesets and attempting to subscribe/unsubscribe from them. It looks like this issue has already been thought up as OSM website issue #842.

Korean language help needed over 3 years ago


Greenville NC needs help over 4 years ago

In JOSM, you can activate the "OSM US TIGER 2012 Roads Overlay" in the WMS/TMS section of the preferences. Then you can activate this layer from the Imagery menu. This will allow you to see the names of the roads from the TIGER dataset. Perhaps many of the new roads that you are adding have names that you can also add.

Auto roads, part 2 over 4 years ago

This is interesting work. Once you figure out the middle of the road issue, you might want to vary the spacing between points based on how straight the road is.

Go Map!! now available in the App Store over 5 years ago

I just downloaded it. This is by far the best OSM editor for iOS that I have found to date.

Massachusetts town and county boundary relations complete! over 5 years ago

From what I understand, the preferred method is to put the language prefix in the tag value (wikipedia=en:Haverhill, Massachusetts) and have the tag key just be "wikipedia" without any language specification.

Massachusetts town and county boundary relations complete! over 5 years ago

Great! Thanks for working on that.

One thing that I've recently learned about boundary relations is that the Nominatim search engine uses wikipedia links to pull in additional information to build its search index. Also, at some point in the last few years, the format for OSM wikipedia tags has changed. On the relation, the tag should be something like:

wikipedia=en:Haverhill, Massachusetts

where en is for english and the text following the colon is the actual wikipedia title of the page (not the URL encoded form like Haverhill,_Massachusetts)

The Three Stigmata of Potlatch Edits over 5 years ago

I'm also finding that some new mappers who don't know about the advanced mode end up trying to shoehorn existing objects into things that P2 simple mode recognizes. In spite of the warning "Try looking at the tags under the advanced properties", they end up clicking the unknown drop-down and then picking something. Then we get things like natural=wetland changed to natural=water and landuse=landfill changed to landuse=industrial.

Brownsville, PA over 6 years ago


The starting point for the map is typically a collection of data that has been imported from various sources. The roads came from the 2005 TIGER road data (provided in public domain from US Census Bureau). They certainly may be quite a bit off from reality. I've found that the Bing images are generally pretty well aligned, but it's helpful to confirm against GPS traces. There may be some that have been uploaded, or you can make and upload your own. Once you've confirmed the alignment of a few roads against GPS and satellite images, you can just use the images to update the roads. For more information about turning GPS traces on in Potlatch 2 (the default editor in your web browser), see:

Note that there was a separate import of features from GNIS in 2009 and these are all single Nodes of POIs like churches, schools, and various public buildings. In many cases these are out of date and should be deleted. Also, they may be quite far off from their actual location.

As far as mapping POIs, some people choose to put single Nodes on the map, and others choose to use Ways to trace outlines of buildings. I prefer to map building outlines as I think it makes a better map. If you have a building with only one POI inside, then you just want tags on the Way for the building. If there's a node inside, you can copy the tags, and then delete the node.

Some buildings may have multiple POIs in them (shopping centers, etc). One method is to make a Way for the building and then put Nodes at the entrance of each shop. Here's a shopping center in Derry, NH that uses this method:

Another method is to make separate Ways for each store in the building (this gets a little tricky since you have partially overlapping Ways). Here's a shopping center in Londonderry, NH that uses this method:

Also, note that when people have imported things for the entire US, they include a bunch of tags on elements that happened to be in the source data. These have little relevance to OSM and should probably be deleted (tags starting with tiger, gnis, etc).

Brownsville, PA over 6 years ago

It's great to hear about another new mapper. I'm originally from Pittsburgh, so it's nice to see people like yourself updating the map in Pennsylvania. Let me know if you have any questions about editing the map.

What's the point of all the TIGER tags? almost 7 years ago

Generally, if I have to significantly change the connectedness or the name of a road, then I just delete all the TIGER tags. If I just need to expand the abbreviations in the name, then I just delete the tiger:reviewed tag and leave the other tags.

Garmin etrex Vista HCx dead again almost 7 years ago

Running the Garmin off USB power is convenient since I don't rarely have to change the batteries (and changing the batteries while driving is probably not a good idea). Does anyone have any idea if there are certain times the car is more likely to have a USB power spike (like when it's being started)? I was thinking I could start the Garmin on batteries, then start the car, and then plug in the Garmin. I will definitely get the Garmin Car Adapter in case that is more robust than the generic USB adapter that I am currently using.

Also, I will avoid leaving the device inside the car. The devices have failed in June and July when it can get over 90 F outside (32 C), probably significantly hotter inside my black car.

Garmin etrex Vista HCx dead again almost 7 years ago

Yeah, I had the original etrex and never had any problems for many years, though I only used that on my bicycle running on AA batteries. At this point, if I'm able to get another replacement, I'll switch to the official Garmin car adapter so that the only non-Garmin part of the chain is the car (unless Garmin makes their own AA batteries).

First edits almost 7 years ago

Great to see another mapper in New England. I've been concentrating mainly on southern NH so far, but occasionally map things in Massachusetts.

Google is pirating OSM about 7 years ago

Could it be that both OSM and Google started their map of the United States by using TIGER data?

I've seen a number of errors on both OSM and Google that clearly stem from the TIGER import.

I also noticed a few roads in West Linn, Oregon which had direction prefixes as imported from TIGER, but I removed the prefixes since they they do not appear on the actual road signs.

Vancouver WA over 7 years ago

You can also try USGS imagery (public domain). Enter the following service URL in the JOSM WMS plugin configuration:

It often has greater detail than Yahoo and NAIP (though it may be a few years old as well).