Project Drift

I’ve done a few more Road Scholar gigs this year, and my co-guide and I both feel that the ride choices could be improved, mainly by doing more bike paths and rail-trails, and doing less actual road riding. This would avoid the biggest issues we face (traffic and hills), and maybe allow the rides to be a bit longer and more enjoyable.

Meantime, I’d noticed a tendency, among our van drivers, to use Google Maps to navigate our pick-up, drop-off and other van access points. This is I think a good thing, but it’s led to map searches finding the wrong drop-off point — nearby features rather than the specific location we use. It works well enough that “OK, turn left here and pull into that parking lot” will get us there once we’re close enough, but navigating to an actual position (a given latitude and longitude, for instance) would work much better.

Finally, I thought it would be good to have an official repository somewhere, of the rides: their official routes (I use GPS to navigate on the rides) as well as waypoints, like lunch spots, points of interest along the ride, and those pick-up and drop-off points. Ideally, I would be able to load a ride into my GPS and have all info for the ride at my fingertips.

These all coalesced in my mind into the Great Big Ride Database GIS Project. The project would be made of three parts: storage of rides (official or otherwise) and waypoints into a ride database, transfer of rides/waypoints to and from my GPS, and analysis of the ride data.

First Steps, and Revolting Developments

I started by keeping “official versions” of our rides on RideWithGPS, and I would download them as GPX files onto my Garmin when I needed them. This would only take care of the route itself, however; I thought that there was also a need to maintain a list of waypoints associated with each route, so I decided to build some kind of database to hold routes and their waypoints.

Since I would like to be able to just hand over the ride information in some file format, my first attempt was to build the database as a GeoPackage file. This actually worked pretty well, when my plan was just to stuff the data into storage. But then, my plans started to morph: I needed to actually analyze the data (with a spatial query) to generate info I needed. The GeoPackage file should have been able to handle this, but I think I must have done something wrong back when I installed the underlying GeoPackage/SpatiaLite libraries, or I was doing something wrong now, but I just couldn’t get any spatial functions to work. After frustrating myself for a while I just moved the database over to PostGIS. My project was changing, but at least it worked.

So at this point, I started looking at the problem of getting the point data to places where I could use it — like onto and off of my Garmin. I collected a bunch of the waypoints as “saved locations” on my GPS, but then I couldn’t find any good way to export or upload them. (The Google tells me that Garmin apparently has some Windows programs that can manage waypoints, but that does me no good.)

I eventually dropped back and punted by writing a Python script. I scrounged around inside my Garmin and found a file called that seemed to be where the saved locations were stored, and used that fitparse library to rummage inside the FIT file, eventually figuring out the (undocumented) structure used to store waypoints. I could now export the waypoints into a QGIS layer, then I managed to realize that I could import the waypoints to my GPS via a GPX file in the same way I could import rides via GPX, and could even combine waypoints with the ride trackpoints in the same file for importing. Major breakthrough! — though the Garmin seemingly ignores all waypoint information (symbology, comment) except the name.

So things are now a bit different than how I first planned it, but I have a system that works. Next up: evaluating potential routes.

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