This PR removes unneeded `CASE` clauses which converts `toll` tags to booleans. However, the `toll` tag is already mapped as a boolean by imposm, therefore this processing can be simplified.
This PR is a refactor. The purpose of this PR is to refactor the logic in the z12-z14 transportation layer to increase readability and reduce code complexity.
In addition, this fixes bugs in the original filter code:
* Create filter parity between `service` and `service_construction` highway classes.
* Removal of unintended `class` values `minor_construction`, `path_construction`, `service_construction`, and `track_construction` from zoom 12 filter by explicitly listing the highway classes that are included.
Fixes#1191
This PR suppresses `highway=service` at zoom 12, where it is not a useful level of detail. This makes OpenMapTiles consistent with openstreetmap-carto, which does not begin showing `highway=service` until raster zoom 14 / vector zoom 13.
Additionally, this PR suppresses `highway=service` + `service=parking_aisle` / `service=driveway` from zooms 12-13, as this detail is excessive below zoom 14. As a point of comparison, openstreetmap-carto does not begin showing `service=parking_aisle` / `service=driveway` until raster zoom 16 (vector zoom 15).
Fixes#366
This PR sets `toll=1` in the `transportation` layer when a road is tagged as a toll road in OSM (with the tag `toll=yes`). If a road is tagged with any other value of `tag=*`, the value is suppressed in the tile, since non-toll roads can be presumed as the default and therefore this PR should have only negligible impact in the tiles.
Support for toll road tagging is of interest in the American mapping community, because toll roads have historically been styled differently on American-style maps, for example:
Screen shot of a toll road being generated in the `transportation` layer tiles:
Fixes#1066
This PR adds a new field `access` in the transportation layer, which will be set to `no` if the `access` tag is either `no` or `private`. While `private` is the more popular value by a 17:1 ratio, I went with `no` because it's smaller in the tiles. In addition, the text `no` opens up the future possibility of other text-based access values such as `destination`, `customers`, or `permit`.
The screenshot below shows an example of access tagging for a road on a military base:
To avoid discontinuous transportation lines between zooms 9 and 11.
- Originally limit geometry by length for z9 - z11 (`ST_Length(geometry) > ZRes(11)`)
- highway z9 to z11 was generalized during import-osm
- now just create a filtered and generalized z11 table
- then merge segments in the same way as from (full-featured) osm_highway_linestring and used this merged z11 for mat.view z10 and z9
Close#1107
