Next virtual trek – my plan didn’t work out

I know this sequence of posts is way off the primary topic of this blog but this will be the last one (on this topic, at least for a while).

When I last left you hanging I described the method I was going to use to acquire an accurate table of distances, fairly closely space (e.g. 3-6km) along the Via Podiensis so I could spend the next year or so on treadmill piling up miles to then “take” a virtual trek. My plan was to use a couple of GPS tracks I found online to get an accurate distance along the entire trail and then pick intermediate spots for my table and know their distances.

Since the software I have on my PC only covers the USA my only available tool (at least in initial plan) was Google Maps (or later tried Google Earth which has more features).  I quickly learned two things: 1) the high resolutions (4000 waypoints) GPS track was very tedious to enter (all manually) into Google Directions which has a limit of 10 points along a route and thus I was getting less than 1km of trail for 5 minutes or so of work, 2) every now and then, but in minor ways Google didn’t want to generate precisely the same route as I could see on the map where I could display the entire track (but not get any distances).

So I switched to the lower resolution track (only 500 points, visually on the maps it’s a bunch of line segments that don’t precisely follow the road/street/path/trail). But I figured I could find the flaws in that and patch in bits of the high resolution data.

Now in some ways I’m really being OCDish about this. What difference does it make to be highly accurate. Well, consider this, a real walk has to go where the path goes, not in straight lines across country or through someone’s house or yard. And most of the backroads where the Camino goes are not straight super highways but meandering paths. Now if you’ve ever hiked in the real world you know your actual path can be a lot longer than just a compass line on a maps. All those zigs and zags add up. The small set of straight line segments would probably be off, in total distance, by hundreds of kilometers. IOW, not much use for accurately converting treadmill miles to a location on the ground in France.

But not to worry, Google knows this and so it actually follows the road between two points on the road. And while it does a bit of rounding in the distance that’s still going to be fairly accurate.

So other than being a tedious process my preliminary results showed, at the cost of more time than I’d hoped, I could get a fairly accurate route.

WRONG!

I was manually entered a set of points, having worked out a record keeping procedure for doing all this and everything was fine and, then, the next point, probably only 50m from the previous with a road showing in map mode and even clearer in satellite photo mode and Google routes this round-about path, about a kilometer that was essentially a giant U-turn to reach that point from the other direction!

No sometimes, at least here doing geodashing in the midwest, that’s exactly what one has to do. Yes there is a road on the map and yes you can see it in the satellite photos and NO you can’t go that way because there is a gate or a damaged bridge or whatever. But presumably the GPS track I’m using means that person who recorded the track DID go that way so it’s possible.

After more experimenting I eventually discovered that what I’m seeing is gaps in the Google underlying database, i.e. some abstracted mathematical description of all the possible roads/paths/trails they know. And in that database you can’t get from point A to point B, at least not just going forward.

So after reading manuals and searching online I eventually discovered (I think) there is no way to solve this. So electronic mapping systems let you manually enter “vias”, i.e. some line segment that connects two bits of road together. That software is letting you use your knowledge (you can go that way) to override their database that can’t allow you to go that way.

But Google isn’t designed for complex routing issues. It’s designed for ordinary users to do simple things and thus doesn’t clutter up its UI with all sorts of advanced features. I encountered this with my standard USA mapping application (now defunct as the company was bought out and their products dropped; I won’t mention the name). That program was for “pros”, people who had complex navigation problems. For a while it was the only car-based solution but gradually the dashboard GPS came out and also, of course, Google Maps on smartphones. Those solutions are generally much easier to use, but they are “dumbed-down” relative to people with complex navigation requirements, which of course is a very tiny fraction of the market that they can afford to ignore.

So after searching for other solutions (there are a few other online mapping systems, but most have even less data than Google) it appears, like my route on the map, I just can’t get there.

As someone so often says, “SAD”.

So that means I have to use the one other data source I have which has two problems: 1) the distances between the 34 overnight stops are rounded off and add up to about 50km less than the known distance of the route (which, often, there are multiple answers to that to be found, but all the distances are greater), and, 2) there are just the 34 waypoints which will takes weeks for me to reach each (yes, the trekkers do them in a day, but I couldn’t imagine doing 20 miles / 6 hours on the treadmill in a day).

Plus my purpose in all this is a “virtual” trek. I did learn that Google has lots of detailed data at short distance intervals, restaurants, hotels, gîtes (the French equivalent of alburgues) and other points of interest. So I need all that detail to “see” what the trek would look like. It turns out that only doing relatively short daily distances on treadmill allowed me to follow (where available) the entire streetview (so literally walk into a town and look around). I have lots of experience looking at satellite photos (though mostly in plains and midwest US which doesn’t look much like France, or even Spain) but online satphotos aren’t the high resolution spy photos so often you can’t “see” very much. And looking at the roof of a house or building is much less interesting than looking at it at ground level.

So while I can use the table I did find, just for statistical purposes, I’m going to have to really guess (from zooming in on GPS track displayed in Google Earth, unless I can figure out how to load KML files into Google Maps) where I am. It’s not going to be pretty and that’s a bummer that make take too much “fun” out of my virtual trek to just bother.

At least one thing, though, is I can take a look at some French restaurants and while I’m not interesting in trying to build a translation app for that at least I can see lots of pretty pictures of food (already seen some, first course in France seems to routinely be pâté not cured meats as in Spain).

So with all this discussion out of the way I can get back to my regular topic, menus in Spain, since Santiago has a ton of restaurants, some with online menus I can decode.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.