Add roads from NaturalEarth

schema/layers/road.sql

@@ -0,0 +1,31 @@
+CREATE OR REPLACE VIEW ne_10m_global_roads AS (
+    SELECT geom, scalerank, featurecla as featureclass, type
+    FROM ne_10m_roads WHERE continent <> 'North America'
+    UNION ALL
+    SELECT geom, scalerank, class as featureclass, type
+    FROM ne_10m_roads_north_america
+);
+
+CREATE OR REPLACE VIEW road_z4 AS (
+    SELECT *
+    FROM ne_10m_global_roads
+    WHERE scalerank <= 4
+);
+
+CREATE OR REPLACE VIEW road_z5 AS (
+    SELECT *
+    FROM ne_10m_global_roads
+    WHERE scalerank <= 5
+);
+
+CREATE OR REPLACE VIEW road_z6 AS (
+    SELECT *
+    FROM ne_10m_global_roads
+    WHERE scalerank <= 6
+);
+
+CREATE OR REPLACE VIEW road_z7 AS (
+    SELECT *
+    FROM ne_10m_global_roads
+    WHERE scalerank <= 7
+);