London Transport Zones drawn by using ConcaveHull method on Google Map

briantist · November 29, 2020, 10:53am

I needed to draw the TfL zones on a Google map and I wasn’t going to do them by hand!

This is

Grab locations for all of the stations in London from TfL (checked with NRE);
Work out which Zone they’re in from either the API or the http://content.tfl.gov.uk/london-rail-and-tube-services-map.pdf map whent the API didn’t know;
Use The Concave Hull of a Set of Points - CodeProject to generate the most optimal perimeter from the set of points;
Draw them on a Google map (with 1999 colours https://www.clarksbury.com/cdl/maps/tube99.jpg )

Here’s the JSON used to create it.

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briantist · November 29, 2020, 11:51am

Here’s the same thing but with “Zones” 7 to 9 on it

jamesevans · November 29, 2020, 12:05pm

Very good. I see you’ve tactically avoided the Tram zone! That would add in a horrible web in Wimbledon & Croydon!

briantist · November 30, 2020, 9:46am

Thanks!

Thankfully… the trams aren’t shown on the map that I’m re-creating. Does TfL know that it’s showing East Croydon National Rail station as being in the Tram zone on the http://content.tfl.gov.uk/london-rail-and-tube-services-map.pdf ?

It’s just odd that this problem was fixed about Morden when Diamond Geezer pointed it out…
diamond geezer !