roads-fill railway ordering (affects ways with both railway and aeroway tag)

[pnorman]

The roads-fill layer has the following SQL for getting railways

SELECT 
    way, prio, 
    COALESCE(
      ('railway_' || (CASE WHEN railway='preserved' AND service IN ('spur','siding','yard') THEN 'INT-preserved-ssy'::text WHEN (railway='rail' AND service in ('spur','siding','yard')) THEN 'INT-spur-siding-yard' ELSE railway END)),
      ('aeroway_' || aeroway)
    ) AS feature,
    horse, foot, bicycle, tracktype,
    CASE WHEN access in ('destination') THEN 'destination'::text 
      WHEN access IN ('no', 'private') THEN 'no'::text 
      ELSE NULL 
    END as access,
    construction,
    CASE WHEN service in ('parking_aisle','drive-through','driveway') THEN 'INT-minor'::text 
      ELSE 'INT-normal'::text 
    END as service,
    NULL as oneway, 
    'no' as link,
    CASE WHEN layer IS NULL THEN '0' ELSE layer END AS layernotnull 
  FROM planet_osm_line 
    JOIN (VALUES
      ('railway_rail',430),
      ('railway_spur',430),
      ('railway_siding',430),
      ('railway_subway',420),
      ('railway_narrow_gauge',420),
      ('railway_light_rail',420),
      ('railway_preserved',420),
      ('railway_funicular',420),
      ('railway_monorail',420), 
      ('railway_miniature',420),
      ('railway_turntable',420),
      ('railway_tram',410),
      ('railway_disused',400),
      ('railway_construction',400),
      ('aeroway_runway',60),
      ('aeroway_taxiway',50),
      ('railway_platform',90)) as ordertable (feature, prio) 
    ON COALESCE(('railway_' || planet_osm_line.railway), ('aeroway_' || planet_osm_line.aeroway)) = ordertable.feature 
  WHERE (tunnel IS NULL OR NOT tunnel IN ('yes','building_passage')) 
    AND (covered IS NULL OR NOT covered='yes') 
    AND (bridge IS NULL OR NOT bridge IN ('yes','viaduct'))

(roads portion omitted)

The problematic SQL is ON COALESCE(('railway_' || planet_osm_line.railway), ('aeroway_' || planet_osm_line.aeroway)) = ordertable.feature
For a way with railway=foo aeroway=runway it wil compute the join as joining COALESCE('railway_foo','aeroway_runway'), which evaluates to railway_foo, which doesn't match, hence preventing the runway from rendering.

[matthijsmelissen]

Is this something that needs solving? I can imagine that ways with both a railway and an aeroway tag are nearly always bad tagging.

[matkoniecz]

Gisborne Airport has just runway/railway crossing but even this is considered as unique.

[pnorman]

Is this something that needs solving? I can imagine that ways with both a railway and an aeroway tag are nearly always bad tagging.

Well, this is inconsistent with formation of a feature column elsewhere, where we do check that the take is one of a subset of values. As an example, see, landcover, which has

(SELECT 
    way, name, religion,
    COALESCE(..., amenity, landuse, ...) AS feature 
  FROM (SELECT 
      way, COALESCE(name,'') AS name, 
      ('amenity_' || (CASE WHEN amenity IN ('parking', 'university', 'college', 'school', 'hospital', 'kindergarten', 'grave_yard') THEN amenity ELSE NULL END)) AS amenity,
      ('landuse_' || (CASE WHEN landuse IN ('quarry', 'vineyard', 'orchard', 'cemetery', 'residential', 'garages', 'field', 'meadow', 'grass', 'allotments', 'forest', 'farmyard', 'farm', 'farmland', 'recreation_ground', 'conservation', 'village_green', 'retail', 'industrial', 'railway', 'commercial', 'brownfield', 'landfill', 'construction') THEN landuse ELSE NULL END)) AS landuse,
    FROM planet_osm_polygon
    WHERE landuse IS NOT NULL
      OR leisure IS NOT NULL
      OR amenity IN ('parking','university','college','school','hospital','kindergarten','grave_yard')
    ORDER BY z_order, way_area DESC
  ) AS landcover
) AS features

(Query simplified)

I see a few rewrites to the query to simplify the SQL that can at the same time fix this problem.

[lkernan]

While the rail line is closed now, there used to be a railway/runway crossing in Australia too.
http://www.airwaysmuseum.com/WYY%20rail%20crossing%201.htm

Uncommon, yes. Bad tagging, no.

[pnorman]

roads-fill no longer has aeroways