10 projects - #2

open street mapping

adding trails and ponds in the pineries open space to open street map

project goal

A new set of trails is being opened near my family's home called The Pineries Open Space. The land had been used for ranching since the early 1900's, but was purchased by the city and is scheduled to open to the public in the summer of 2020. I stumbled on a newly-created single-track trail recently on a run, and have been enjoying exploring these woods ever since.

Because the area was private land for so long, and the park is not yet open, maps of the area are sparsely populated. While running in the woods this morning, I decided that the project of the day would be to add the trail and ponds to public maps.

The idea of mapping a trail alone doesn't seem so difficult, but it does force you to think about where data on digital maps comes from. In the earlier days of internet mapping, map data started to become collected by big companies and locked down. In response, OpenStreetMap was created on the model of Wikipedia. People know their environments best, and can add that data to a public and open map. Since the founding in 2004, OpenStreetMap has become one of the great public wonders of the internet, with more than 6 million mappers contributing data to a global map. This data is in turn used by different applications.

To visualize the scale of mapping, and the collaborative nature of the data, check out this map created by Eric Fischer and the associated blog post from Mapbox. Each feature on the map is colored by the user that contributed the map data.

methods

As you might expect, OpenStreetMap makes the onboarding process easy. Simply create an account, and go through an informative tutorial. Most map editing is visual, done through the "iD Editor."

To map the trail, I first imported a GPS track from a run along the trail to use as a reference. Because of GPS inaccuracies, it is recommended to visually trace the path of the trail as it appears on satellite imagery.

Spotting the trail in the satellite imagery was challenging because most of the images were taken before the trail was constructed. I was able to use a combination of Bing maps imagery, and imagery from the National Agricultural Imagery Program (NAIP). Here you can see the trail on the Bing imagery (L) and on the NAIP imagery (R).

I also added ponds and dams present in the woods as well. These were easier to find and trace than the trail.

results

Here are the trail, ponds, and earthen dams in the woods that I added to the map. You can view the data on OpenStreetMap as well.

conclusion

This was a simpler project, but it's a good feeling to add to a public record like OpenStreetMap or Wikipedia. I'll be very interested to see how this data spreads.

what would i do next

• Monitor sites like Strava and Mapbox to see when they pull new data from OpenStreetMap.
• Update the path position as the more satellite imagery sources show the trail.
• A new trail is being constructed. Add that trail to the map after it is complete.