Let's add a trail to OpenStreetMap.
Multi-use trails add character to a neighbourhood and to a map. Here is a way to add your local trail to OpenStreetMap. This is a suitable first mapping project when you get a GPS receiver, and this is the sort of mapping that you can do with family and friends.
I know from local knowledge that there is a multi-purpose trail in this new neighbourhood. Before our survey, the map does not show the trail.
Grab the GPS and the kids and let's go mapping.
When you get to the trailhead, switch on the GPS and let it acquire a good signal lock. Pop the GPS in your backpack and enjoy a trip around the trail with the family. When done, switch the GPS off. That doesn't seem like such a burden does it? You get a nice outing with the family and you get to do some mapping without them rolling their eyes quite so much.
I believe that this is trail is a loop when complete, I've only surveyed a portion of it so far. That's okay, of course. When contributing data to OpenStreetMap, one may contribute as much or as little as they choose.
When you have some quiet time to edit, get the track file from your GPS receiver and take a look at it with your favourite editor.
Here we see my walk around the trail. I'm a little surprised that the beginning and end of the track file appear to be about 60m apart, when I switched the GPS on and off at approximately the same location. This should serve as a reminder that GPS receivers, and their operators, have limitations. I may have started before the device had a great signal lock, or the reception may have drifted due to satellite movement, local interference or alien attack. Hard to say what the cause is, but I'll have to keep this reception problem in mind as I edit.
Let's get the current OSM data.
I've zoomed out a bit to get some of the surrounding area as well as the extent of my track file. Everything looks about right. Let's start at the beginning and have a look at that surprising separation between the beginning and end of the track file.
My recollection of this trail entry is that it is straight across from Silverthorne Drive. The finishing position is closer to that than the starting position, which suggests that I didn't let the device get a good signal lock, but neither track is right on the nose. I'll go with my memory on this one and put the trail entrance across from the road. I'll connect the trail entrance to the road centerline because the trail does connect to the road. It even has a paved ramp from road level to sidewalk level.
Each of the trail entrances I saw had a small paved section, while the trail itself was gravel. In the screenshot above I have added the paved sections and marked them as
I'll use this same set of tags for the other trail entrance stubs, so keep the way selected and press [ctrl]-c for
copy, as I draw in each stub I can use [ctrl]-[shift]-v
paste tags to add those same tags to the currently selected way, rather than retyping them.
I'll add the other entrances now. I have emphasized them in this image for clarity.
Now I'll add an unpaved portion of the trail.
When adding to an existing way, JOSM helpfully continues that way with the same tags. This is mostly-good, but we'll make a small change after adding this section to correct the surface value. After adding the trail, I returned to the entrance stub, and selected the node where the pavement ends. Press
split the way at that node.
The image above shows that way with the unpaved section selected after splitting. Now correct the surface value for the unpaved portion of the trail. Select the
surface value from the properties list, press the
edit button, then change the value from
gravel and press the
save button to close the edit properties dialogue box.
and use [ctrl]-c to save this set of tags for the remaining trail sections. Now I'll add the remaining unpaved portions of the trail.
You'll notice that I don't exactly follow every twist and turn of the track file when I add the highway=path.
Notice the upper right corner of the image above. The track file suggests that I doubled back quickly then continued clockwise along the trail. That isn't what happened. The track file is showing a symptom of a reception problem of some sort. All GPS track files from consumer grade GPS receivers show these types of flaws. So don't be too concerned about them. Also don't try to follow every twist and turn suggested by your track files. Use your notes and observations as well as the track file as a reference.
We've added the trail and this survey could be considered complete. I'll add just a few extra items to make things easier for future mappers who may want to improve this area. That future mapper might even be me, so I like to treat future mappers nicely.
Each trail entrance has a gate to prevent unauthorized motor vehicle access. The gates I saw were similar to this one photographed by Bob McMullen, which allows foot and bicycle traffic to pass without opening the gate.
I did not mark the exact location of the gates during my survey but they are each close to the road. I'll estimate their locations. From my imperfect memory, I'll guess that the gate was three metres from the road.
Our map shows the road centerline, so I'll add another three metres and place a gate approximately six metres from the road way as shown above. Then add the appropriate access tags for the gate.
Since this is imperfect and
guestimated, I'll also add a
note tag for future mappers,
k:note v:gate position estimated
And lastly, I did not survey the complete trail.
There is more trail to walk at each end, so I'll mark them as
fixme so interested mappers can find them, survey more of the trail and improve the map even more.
k:fixme v:trail continues
And the final steps are to upload the edits to the OpenStreetMap server using either the upload button on the menu bar, or by pressing [ctrl]-[shift]-u, and adding an informative changeset comment.
k:comment v:Cambridge Ontario, Mill Run Trail, foot survey and "add a trail" tutorial
Gate photo © Bob McMullen is used by permission of the photographer. Thank you Bob!
OSMer, Ed Loach suggested adding the tag
k:limbo_dancer v:right for the gate which gave me a nice laugh. Thank you Ed.
This tutorial is one of a series of tutorials for OpenStreetMap beginners.
This article was originally published on Fri, 08/20/2010 - 01:30.