mvexel has commented on the following diary entries

Post When Comment
How would you map this? about 2 months ago

escada: I've seen transit -- it looks more complex to me than turnlanes:turns for mapping lane connectivity. Can you help me out mapping this intersection using the transit schema? I think relations would be needed, but not sure how to map the transition for example from 1-2-3:


It looks like 1-2 can be done with ways, as indicated below, but I am not sure how to identify that the left turn lanes from 2 to 3 lead to the left two lanes of segment 3.



Mapping turn lanes in OpensStreetMap about 2 months ago

My recent diary entry with a 'mapping challenge' for a complicated intersection is relevant to this topic. I'd appreciate your feedback!

How would you map this? about 2 months ago

Wow, thanks for all the feedback.

I am happy to see people seem to prefer the turn:lanes approach so far, which is simpler than the relation based schema I have also seen. Mapbox had a blog post that highlighted both.

One thing that would still lead me to want to use relations in some places is my second 'requirement' to correctly identify lane connectivity -- exactly which (turn) lanes connect to which. So how to map that making a left turn here (1->2->3)


means that you have to go from lane to lane on the consecutive ways like this:


For that you would still need a relation, or is there a simpler / other / better way?

How would you map this? about 2 months ago

My question is not specifically aimed at CFI mapping. I just chose this intersection because it's reasonably complex.

Just Joined open street map. 2 months ago


A lot of US based OSM mappers are on the Slack channel which you can join here:

There is also a US specific mailing list you can subscribe to:

Maproulette Newsletter - March 2017 3 months ago

I removed the Island challenge from this post since it was not made visible in MapRoulette yet. See this blog post for some context.

Are maproulette challenges undiscussed mechanical edits? 3 months ago

To clarify how to find the challenge creator for a visible challenge: use the search box (or the map) to identify the challenge you are looking for:


Then click on the marker, which will have a link to the OSM user who created it:


You will see 'SuperUser' for older challenges because we did not store creator information in earlier versions.

Are maproulette challenges undiscussed mechanical edits? 3 months ago

The challenge creator should be visible when you click the challenge's marker on the map on the main page. You can use the search box in the top left.

However if you try to apply that to this challenge you will come up blank. The reason why is that the user's project is not set to 'visible' which makes all the challenges that belong to their project also won't show up. The creator apparently did not intend to make this challenge public yet, and as such I made a mistake to highlight it.

The 'visibility' of a challenge only applies to whether it is visible on the map on the main page, and whether it shows up in the search results. It will still show up in the API. The reason why users can't make challenges completely 'private' is exactly what we are talking about here. I don't want there to be some 'shadow' activity that nobody can inspect.

As you can see from the API output the user who created this challenge has OSM ID 5441336.

I realize that it's not so easy right now to get a complete overview of the Challenges available in MapRoulette. It is one of the priorities to fix this. One thing someone could do in the mean time is to use the MapRoulette API to create an external list of Challenges.

Are maproulette challenges undiscussed mechanical edits? 3 months ago

I don't think this is necessarily a MapRoulette problem, but I do agree that it would be beneficial to have challenges checked for some basic quality standards, so that people who fix things through MapRoulette are properly prepared. That is part of the reason why I asked for someone or a few people to step up and become Challenge admins in my latest MapRoulette newsletter. I don't yet know precisely how that would work, but I envisage for now that I would provide a weekly list of new public challenges and the users who created them for the admins to review.

In this particular case, I would get in touch with the Challenge creator (there is a link in MapRoulette to their user profile) and ask them to comment here. Any problems with individual mappers making bad edits should be addressed with them. Again, I don't think that users making questionable edits is specifically a MapRoulette problem. If I were to shut down this Challenge, What is to stop them from just scrolling along the coastline looking for islands to fix in the same way they are doing it now?

MapRoulette newsletter 4 months ago

MikeN I can't keep up with these railway mappers!

MapRoulette newsletter 4 months ago

Correct, thanks you you I believe :) I'll edit the post.

Adding unknown roads using ImproveOSM 4 months ago

That's a good idea. Unfortunately we don't have access to that information in most cases. The GPS locations have been anonymized to exclude things like the timestamp, so they can't be used to determine the speed driven.

Passion for maps, graphs, and data 5 months ago

Welcome to OSM!

Attn: Mappers in SE Michigan, US 6 months ago

Very cool, good luck!

Finding the local experts 7 months ago

Richard, I still feel bad about never coming through with completing that effort...Who can I muster to revive it?

Cemeteries in Texas MapRoulette Challenge now powered by Texas Imagery Service 8 months ago

BladeTC I agree! Perhaps this challenge should be marked as 'hard'.

Cemeteries in Texas MapRoulette Challenge now powered by Texas Imagery Service 8 months ago

The imagery I used as an example is different in source from the imagery used for the MapRoulette imagery. The example here was commissioned by Texas itself, and is indeed in PD. The imagery in the MapRoulette challenge is licensed from Google by Texas and made available to MapRoulette specifically. So I can't say positively that it's OK to add this imagery to JOSM or iD, and removed specific instructions to do so.

I will add a note to the body of the blog post to this effect. I will see if I can clear up the legal status of OSM use of this imagery asap.

Spotting Cemeteries in Texas 8 months ago

I am writing a follow up blog to clarify and update with new details and imagery!

Easily create OSM-based apps in Python with OSMAlchemy 9 months ago

Would this be related to the Overpass API python wrapper in any way? Can you point out similarities / differences between the projects?

History of all Tags 10 months ago

Very cool!! Interesting to explore the data that way. It's fun to try and recreate what happened, for example here:


My guess: * People started mapping ways with center_turn_lane=yes * Someone decided that those tags needed to go away and wrote a bot * Mappers decided to use it anyway :)

Oh but wait:


New guess: * Someone decided that the correct spelling was centre_turn_lane and wrote a bot to rename the tags * Mappers decided to use center_turn_lane anyway :)