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OpenStreetMap Carto (AJT)

This is based on a version of https://github.com/gravitystorm/openstreetmap-carto as of summer 2014. Most of OSM-carto's Readme still applies, so I'll not duplicate that here.

Why? A bit of history.

The initial problem that I was trying to solve was that OSM's "standard" style, being international, didn't understand England and Wales' curious access rights mechanisms. In OSM, the "designation" tag is used to describe this. It's quite common to have a private road over which you have explicit legal foot-only access, and OSM's "standard" map can't be expected to show it because it's very much a local oddity.

I therefore created https://github.com/SomeoneElseOSM/designation-style which was a lua style file that changes the rendering database contents so that footpaths, paths and tracks instead contain "designation" information. The OSM standard style file can still be used, but where a "footpath" appears on the map it now explicitly means "designation=public_footpath" rather than "highway=footway".

This makes sense for a couple of reasons - there are only so many different concepts that you can communicate at once from one item on a map, even more so on a mobile phone screen (which is what I'd usually be using). The other reason is that it's far, far easier than expanding the style rules within highway rendering to support a completely new concept in addition to the ones that it already handles.

In summer 2014 a number of changes were made to OSM's standard style that made it decidely less useful for displaying maps that aren't of city centres. See for example issues 542 612 641 747 and 765. It became clear that the primary goal of OSM-carto was something that looks nice rather than a map usable for navigation.

So what to do? The first thing was obvious - start using my own tiles rather than osm.org's. I created https://github.com/SomeoneElseOSM/SomeoneElse-style to incorporate the "designation" changes and fix a number of rendering issues (e.g. names for portions of landuse). That also adds a few things back to the map like abandoned railways and guest houses.

However, this approach is restricted to the stylistic elements supported by the parent OSM-carto style. There are some changes (the zoom level and prominence with which elements are displayed, and adding new elements altogether) that need actual style changes. Those changes were made here - but only those changes that can't be handled in lua.

Changes made at the stylesheet level

On a PC browser at zoom level 13, the width of the display is roughly "a nice day's walk". It therefore makes sense to show things from that level upwards. Where there's a bit too much detail you can always zoom in for clarification.

  • Lightened landuse. Lots more landuse is being added to OSM, and the default landuse in my bit of the UK is farmland and heath. It therefore makes sense to use a significantly lighter colour for these.

  • Displayed hedges and barriers at lower zoom levels. These are now displayed (as narrower lines) from zoom level 13 upwards and as before from zoom level 16.

  • Display parking from zoom level 13 instead of 16. A rural layby can be hard to find, and there aren't so many of them that displaying at zoom 13 would cause a problem.

  • Display stiles on the map at the same level as gates. A new icon for stiles based on the gate icon was created.

  • Display secondary and tertiary roads with sidewalks (using a wider casing to show the sidewalk)

Other changes: