If you have never contributed to OSM, the process can be pretty easy:
Go walk/hike/bike the trail so you remember what it looks like, perhaps taking notes and recording a GPS trace of it.
Go to openstreetmap.org, make an account, move the map to the area where the trail starts, click "Edit".
If you recorded a trace, drag it into the editor so it can show it as a reference (hopefully it's a GPX, it might be necessary to convert it).
Using the "line" tool, trace the trail, combining the information from the GPS trace, notes and imagery. Make sure to select the finished trace and mark it as a walking/biking/hiking trail. Then click save.
So there is a lot to do, but none of the individual steps are hugely complicated.
I'm still slightly new to editing OSM as a MTBer, maxerickson and c0nsumer have covered the details of how to do this already very well, but i found after comparing a seemingly never ending number of competing apps in this space, i found Viewranger GPS really useful:
a) For planning routes in advance to then download to your smartphone and follow using the app (as mentioned elsewhere OSM was definitely the best mapping layer to use for this both as a resource and as a mechanism to feed your own updates back in).
b) For creating tracks from the routes you've actually cycled which can then be uploaded to the website for later examination.
c) In addition to b) you can annotate your uploaded track on the website with actual pictures from the journey round. These can be from a number of sources (i use flickr) and it will either time sync or gps sync them to the route so you get a nice one stop for looking at previous trips. This has the added benefit you can just take pictures as your going round to then refer back to when fixing OSM without having to worry about making notes as to where it was etc.
Has anyone else used this app or anything else to do this as i'd be interested if there's any alternative ways.
That is amazing! One thing I'm very interested in is the vertical data which Strava seems to be very good at interpolating from GPS traces. Do you know if they contribute that data anywhere?
Thank you! That was very interesting. I had assumed that they were interpolating GPS data, but I guess not. It seems they are smoothing it, though.
That being the case, perhaps I should write the program I was thinking of writing. Even though GPS elevation data is really, truly horrible I think you could probably use statistical techniques to get good data with enough GPS traces. Even routes that are mildly popular can have thousands, or tens of thousands of rides per year. Each one of those rides on Strava has GPX data associated with it. I'm sure it would be more than enough.
Unfortunately, I have about a million other projects on the go :-P
