# Problem description
#1128 introduced route relation concurrency information in OpenMapTiles via the `route_X` attributes. The original implementation assumed that there would be a single route relation for each `network` and `ref` pair. However, it is increasingly common practice to tag a separate route relation for each direction of a route in order to provide awareness to routers and other data consumers of the directionality of a route. This standard and growing practice is described on the [OSM wiki page on route directions](https://wiki.openstreetmap.org/wiki/Route_directions). Thus, the naïve implementation of #1128 caused duplicate entries to be added as `route_X` attributes in the case where separate route relations were used for directional routes.
# Solution description
This PR adds grouping when computing route concurrency information, such that duplicate entries are coalesced in a predictable way. Since this grouping is done only within a route membership join of a single member way, the computational complexity should be trivial.
Fixes#1148
This PR adds expressway tagging to the `transportation` layer, by setting `expressway=1` for non-motorway roads tagged `expressway=yes`, and omitting the tag otherwise. Additionally, I've added a few unit tests to verify that the expressway tagging is being imported and updated into the intermediate tables.
Here is an example of expressway tagging on US-1 in Rhode Island, USA:
I discovered this bug while investigating issues with the updates process related to #1190#1292, and #814.
The `transportation_name` layer produces slightly different `tags` hstore values in the `osm_transportation_name_linestring` table during the initial import versus when running an update. As currently written, the import code produces null-value keys in the `tags` column, while the update code suppresses them. This PR removes that difference and makes the import code use same method that is currently used in the update code.
With a test case I've written, the import code produces a tags hstore that looks like this:
`"name"=>"OpenMapTiles Secondary 2", "name:de"=>NULL, "name:en"=>NULL, "name_int"=>"OpenMapTiles Secondary 2", "name:latin"=>"OpenMapTiles Secondary 2"`
...while the update code produces a tags hstore that looks like this:
`"name"=>"OpenMapTiles Secondary 2", "name_int"=>"OpenMapTiles Secondary 2", "name:latin"=>"OpenMapTiles Secondary 2"`
Note the missing NULL values.
This bug causes a small amount of space wastage after an update is run, because the update matching code detects the `tags` value as different, resulting in a duplicate copy of the tags value if that row is updated. This causes duplicate objects and breaks GROUP BY clauses that expect to group same-tagged features together. I've tested this by inspection of a generated mbtiles, database spot checks, and the unit test code included in this PR.
Closes#271
This PR adds track and path rendering at lower zooms than currently provided, and also achieves near-parity with openstreetmap-carto on track and path rendering. A previously-abandoned attempt, with significant discussion, was #1169.
This PR adds unit tests for the transportation layer, and fixes several bugs in the unit testing code. It verifies the correct zoom association to the various highway classes, and verifies that updates to highway attributes are populated.
Additionally, the documentation for unit tests in the CONTRIB guide is updated to note the specific make commands for developers to run.
