Sunday, April 10, 2011

One Mapper, One Year

Today is the one year anniversary of my first OpenStreetMap edit! I thought I would take the opportunity to reflect on how OSM and myself have had an effect on each other. My intention is not to brag about all the mapping I have done but rather to point out some different ways in which contributions can be made and some of the tools I use when mapping.

My very first edit was to add a foot/bike path near my apartment so that it would show up on OpenCycleMap. Unfortunately the imported TIGER roads were so far off that I had to realign them before I could add the path in the correct location. And of course correcting the ones right around the path led me to correct the ones connecting to those and the ones connecting to those and so on... At the time I didn't even know what TIGER was or what all those tiger:* tags were on all the roads.

Some highlights since then:
  • GPS trackpoints uploaded: 283,271 in 75 traces (most from my Garmin Edge 305)
  • 410 changesets created using Potlatch, JOSM, OsmAnd and Vespucci
  • Pictures taken: over 2,000 (4.5 GB saved)  Most were geotagged to a GPS trace to aid in mapping features (uploaded some of them to
  • Some of the locations I have edited: 
  • Map objects affected (according to - last updated in January)
    • Nodes: about 165,000
    • Ways: about 24,500
    • Relations: about 500 (I created over 200 county relations in 3 states since the last update)
  • Contacted multiple government agencies in Kansas to get explicit permission to use their data to assist in mapping. Documented these data sources on the Kansas page in the wiki
  • Started a blog (self referring link!)

Now for a pretty picture. Here are all the GPS traces in my city. I think there may be one or two from other people but most of it is me.

GPS traces in Manhattan, KS

Most of them were collected on my bicycle although there are a few roads in town that I do not bike on because I do not have a death wish so those were done in the car. But I still have work to do! On Saturday I was talking to some people in the Flint Hills Area Bike Club and heard laments of new streets missing from maps. They were of course talking about google maps but if these new streets are added to OSM first, I may have some converts!

And speaking of converts, I have also had the pleasure of working with some other locals to enhance and use OSM data in interesting applications. For example, Michael Wesch is a professor at Kansas State University. He used OSM data to make a bicycle safety map for the city. In trying to get the map into a usable state, he added a lot of the bigger landuse areas in the city that you now see on the map. He also convinced the College of Architecture, Planning and Design to focus its "Design Days" project on bicycle friendliness and to use OSM as their map. Almost 200 students were sent out into the city with walking papers to find any bicycle oriented path or amenity that wasn't on the map and report back to people on campus who then entered the information into the OSM database. I had about 10 minutes to teach 10 people how to use JOSM. Oh the things I would now do differently.

Several new paths were found that connect neighborhoods and open up the option of safely commuting on a bicycle or by foot to school and the university. Many of these paths will never make it to google/yahoo/bing/etc maps because they are not officially maintained or even known about by city officials. They are just paths that people have worn into the ground by repeated use. At the end, each group presented plans for improving one section of the city and most used OSM renderings in their presentations. I will admit that I felt a sense of satisfaction seeing mapnik renderings of the city printed out on three foot wide paper and being displayed in projected presentations.

A giant printed map for people to mark on at the Design Days public presentation

And speaking of the university, my involvement in OSM got me interested in geographic data in general and I decided to take advantage of the university employee tuition discount. I took a cartography course last fall and am now in the middle of the GIS I course. It is interesting to see differences in the way OSM and "professional" GIS applications (mostly ESRI ArcGIS for these courses) handle data and allow you to interact with it. Both have different strengths and weaknesses.

After my dramatic and internationally anticipated* entrance into the blogosphere with my TIGER ways in Kansas post, I was made aware of and encouraged to attend WhereCamp5280 in Denver. Here I met Steve and Hurricane Coast, Richard Weait and Samat Jain among others. I learned several things that day and had some fun while I was at it. Ski mapping in Winter Park the next day didn't hurt the "fun" aspect either!
*for some definition of "dramatic" and "internationally anticipated"

A lot of my mapping has obviously been local to Manhattan, KS. (Note: I have heard rumors that some other "Manhattan" exists up in the northeast of the country. I have been unable to verify this rumor personally and assume it is false based on my own empirical evidence) This is OSM's strength. Get people who know their own neighborhood to add detail to the map and then update it as it changes. As evidenced by the GPS traces above, I have explored much of the city. Doing so on a bicycle has been really fun. I have discovered interesting neighborhoods and parts of the city that I had never seen before. It surprised me how much I did not know about this relatively small city even after having lived here for over 10 years.

Current map of Manhattan, KS

Other edits have touched places that I have visited on trips. After the trip to Denver, I edited all along I-70. Mostly just improving alignment plus adding the occasional gas station, hotel or other business along the interstate that I managed to snap a picture of as I went past. I also ended up fixing a major cloverleaf intersection in Denver that the local OSMers hadn't gotten to yet. Tsk. Tsk.

Some of the more regional editing started with tracing the Kansas River from USGS imagery. Someone else happened to be doing the same thing, starting from the east. I started from the west and we met up in the middle. More recently I have started doing some edits that touch much larger areas. For example, while browsing the MapQuest Open map, I noticed that county name labels were being placed towards the southeast of the county instead of the middle where you would expect them to be. After some investigation I realized that they are rendering the county name from the place=county nodes and that when these were originally imported, they were all off in the extreme southeast of their counties for some reason. So I used an XAPI query to get all the county nodes in Kansas and another one to get all the county borders. Then I moved all the nodes to be approximately in the center of their respective counties. Now the MapQuest site shows county names in the correct location.

While local mappers are key to OSM's value, people with some data analysis skills and above average technical abilities are also needed to tend to some of the "bigger" data that local mappers may not notice or care about. In the US, a lot of this data that needs tending to comes from data imports. Administrative boundaries, TIGER data, etc. Imports is an entirely separate topic that I won't get in to here though.

Another issue that requires some data analysis is tagging. Luckily we have some great tools such as tagstat and taginfo to help explore tag usage. One problem with tags is typos. Recently I got a message from a mapper who discovered through one of these tools that I had mistyped the word "petroleum" when mapping some of the oil wells south of the city. Thanks to JOSM's auto complete feature when entering tags, the typo had been applied to all of the wells in the area. Thanks to this other mapper discovering the outlying values in this tag, the typo was discovered and corrected.

Another problem with tags is inconsistencies. Unfortunately, as with many open source projects, documentation seems to be a low priority. When I first tried to figure out how to tag a doctor's office, I found 3 different pages on the OSM wiki describing how to tag them. One of them was just a stub page. The other two were fairly well fleshed out. But by looking at the tagstat I found that the one that was being used the most by far was the tag corresponding to the stub page. It looks like this has been cleaned up somewhat now. There are still two different pages with a proposal to merge them.

Initially I was really frustrated by the disorganized tagging rules. In my day job, inconsistent data is sometimes worse than missing data. I still haven't entirely gotten over it but at the end of the day, I consider the various sources and tag things however it makes the most sense to me. The bad thing about such an approach is that it makes the OSM data harder for our consumers to use because they have to consider all the tagging variations for a given type of object. The good news is that since I had these problems, a lot of commonly mapped objects have been added to presets that various editors have so most users don't need to know about the intricacies of tag values or the impressive debates that surround them on various mailing lists. Just use the preset and you're done - and the data is consistent.

In summary: It has been a fun year learning how to map, meeting other mappers, getting involved in the mapping community and experimenting with map data. I plan to continue! In fact, I just recently decided to make the relationship official and became a card-carrying member of the OSM-US foundation. Although I'm still waiting on the actual card to arrive. In the meantime...

Map the planet!


  1. I just want to say very nice work. I am in Wichita and was looking around for other Kansas mappers and am impressed at the work you have done. Keep up the good work.

  2. Thanks! Also, another mapper in Kansas! Yay! I've done a few edits in Wichita myself. I get down there every once in a while to see friends. Is there anyone else active around there? Maybe next time I'm down there there could be a Kansas OSM meetup! :)