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15 Apr
11:47am, 15 Apr 2024
30,395 posts
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fetcheveryone
The reason you see them at different zoom levels is because of the way that online maps work.
Online maps are made up of square tiles. The software works out which tiles are needed for the map area on display. When you drag the map, the tiles that disappear off the edge are effectively thrown away, and new tiles are loaded to fill the empty space.
There's a whole set of tiles for every level of zoom. When you're zoomed right out, the tiles say things like "Birmingham", and have motorways and county boundaries. As you zoom in, you get to see A-roads and rivers, and small towns; and then footpaths and pubs and streams.
There's a database somewhere that plots all of these features. There'll be a set of latitude/longitude pairs that represents the M1; and another that represents the footpath at the edge of the village. And a whole bunch of individual points representing statues and post boxes and bus stops.
And then there's a layer of software. It uses the data from the database to make tiles. And it decides which details to include in any given tile based on the zoom level. At low levels of zoom it ignores all the tiny details and just does the big stuff. At high levels of zoom it includes all the details, but that's ok, because it's just a small area.
These tiles are just images on a 'tile server' somewhere. There are usually multiple tile servers, in order to spread the load. The map owner will have rules that govern how often these images are replaced e.g. if a new feature has been added, or (as a backup) if the tile is older than a certain number of weeks.
Some childish person has flung a whole load of spurious data at the map software. It looks as simple as "pick two random points about a mile apart, and make a road. Call the road something like Andy [INSULT GOES HERE] Townsend".
It's likely that the ability to add this spurious data has been removed already. Stopping the problem at source is usually the first step. And the data may already have been removed from the map database. It may just be that various tile servers around the world are still catching up.
It might possibly have an impact on directions too. Map databases can act as a list of connections between locations - so clever software can use them to build routes. Given that each road/path etc is a connection, spurious roads may make it into that list of connections, and may be offered up as part of the directions you receive. However, I think this is pretty unlikely. All legitimate paths are usually connected to each other - whereas these appear to start and end without any seamless connection to legitimate paths. So it's likely that they'll be ignored as route options.
My guess is that these rogue roads will disappear over the next few days 
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15 Apr
12:32pm, 15 Apr 2024
6,492 posts
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jelly
Stupid woman, plotted my route and missed my bug!
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15 Apr
12:41pm, 15 Apr 2024
17,811 posts
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57.5 Days of Pain
Thanks for the explanation Fetch.
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16 Apr
6:14pm, 16 Apr 2024
19,409 posts
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NDWDave
I spotted a new traffic light near Rotherhithe tube station which will hopefully pay dividends this Sunday.
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19 Apr
11:56pm, 19 Apr 2024
8,723 posts
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Pothunter
I count 4 on the route for you Dave!
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20 Apr
6:05am, 20 Apr 2024
6,511 posts
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jelly
I’ll be running my mile somewhere on route Sunday!
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20 Apr
8:22pm, 20 Apr 2024
19,412 posts
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NDWDave
I count 4 on the route for you Dave!
Yep. I bagged another with a bit of an extension to my Friday lunchtime run
I think part of what I like about Fetchpoint is rewarding long term plans and strategic route planning.
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20 Apr
8:26pm, 20 Apr 2024
68,655 posts
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Velociraptor
And then after 30 days the results of the long term plans and strategic route planning are composted
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21 Apr
11:33am, 21 Apr 2024
19,413 posts
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NDWDave
It would good to have an annual leaderboard too. Or monthly cumulative starting from zero like the olden days
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21 Apr
11:34am, 21 Apr 2024
19,414 posts
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NDWDave
* in addition to the rolling 30 days
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