I’d like to propose/discuss to apply color to GPS traces based on their age.
During these years I found tons of paths (especially footpaths) on the map that does not exist in the real world, very often because of deeply overgrown vegetation or destroyed by some tractor, etc…
Because of this, I’d like to know how recentely people walked/rode that path way more than their direction.
Surely we can use Strava traces together with the Strava Heatmap browser plug-in, but many times people walking in the woods are not athletes and it does not make sense to disregard the very same info about OSM GPS traces.
Not sure if this topic is more appropriate in “General talk” or “Help and support”.
I’ve thought about this as well, and I agree. Especially in the case where road geometry has changed, making old GPX data misleading/outdated.
One problem is that the GPX tiles seem to be rendered iteratively. That is, new traces are “baked onto” the old tiles. (I might be wrong about this, but after stumbling through the code and reading a few discussions that’s my understanding.)
An idea I came up with was to add behavior such that every time a tile is updated with a new trace, before drawing the new trace over top, just reduce the old tile’s alpha channel by 1 bit. That way old traces will slowly fade into nothing (over 255 steps) as new traces are uploaded. Areas with little to no activity would be unchanged.
Similar changes could be implemented but reducing color saturation instead of opacity.
I opened an issue to track this feature idea. This is one of many ideas we’ll explore as part of a broader effort to modernize the GPS tile functionality, in case it turns out to be feasible with the tech stack we decide on.
About “just reduce the old tile’s alpha channel by 1 bit”
I would not make the old traces to fade based on newer ones being added.
I think that the fading (or better a heatmap like Strava) shall depend on the absolute age, not relatively to new traces.
For example: if a path has been walked just once but 10 years ago I’d like to see that trace almost completely faded away (or “cold” in case of heatmaps), even if no other more recent trace has been added on top.
(that’s on the assumption that I understood what you are saying!)
I think GPS traces are really a big value and I’m afraid there is not just a single usage.
Some of us would like to see color codes based on speed, some other directions, some other height from ground, some would even like to know on which kind of vehicle you were travelling on while recording!
So I’m totally on the idea suggested in the GitHub Issue to “accommodate multiple color-coding schemes”. Then I’m not the one coding for it so I can just kindly ask for it
Hi Dario, I also think GPS traces could be used much better.
Building a heatmap from OSM traces has actually been on my to-do list for a while. I’m having some trouble accessing the overall trace database, since the current APIs are not particularly convenient for this kind of use, but I’m working on it. Once I have something usable, I’d be happy to show it to you if you’re interested.
I think your idea of taking the recording date into account is very good, although it adds another layer of complexity.
As far as I know, Strava’s heatmap does not really distinguish between older and newer traces. The “heat” mainly represents how frequently a route is used. My understanding is that Strava includes activities from roughly the last 12 months, but treats them together rather than visually distinguishing recent activity from older activity within that period.
