diff --git a/layers/transportation/layer.sql b/layers/transportation/layer.sql
index 481603a..9da7f96 100644
--- a/layers/transportation/layer.sql
+++ b/layers/transportation/layer.sql
@@ -64,7 +64,7 @@ RETURNS TABLE(osm_id bigint, geometry geometry, class text, ramp int, oneway int
         WHERE zoom_level = 7
         UNION ALL
 
-        -- etldoc: osm_highway_linestring_gen3  ->  layer_transportation:z8
+        -- etldoc: osm_transportation_merge_linestring_gen3  ->  layer_transportation:z8
         SELECT
             osm_id, geometry, highway, NULL AS railway, NULL AS service,
             NULL::boolean AS is_bridge, NULL::boolean AS is_tunnel,
diff --git a/layers/transportation/merge_highways.sql b/layers/transportation/merge_highways.sql
index 55647de..138320c 100644
--- a/layers/transportation/merge_highways.sql
+++ b/layers/transportation/merge_highways.sql
@@ -24,7 +24,7 @@ CREATE INDEX IF NOT EXISTS osm_highway_linestring_highway_idx
 -- Improve performance of the sql below
 CREATE INDEX IF NOT EXISTS osm_highway_linestring_highway_partial_idx
   ON osm_highway_linestring(highway)
-  WHERE highway IN ('motorway','trunk');
+  WHERE highway IN ('motorway','trunk', 'primary');
 
 CREATE MATERIALIZED VIEW osm_transportation_merge_linestring AS (
     SELECT