diff --git a/layers/transportation_name/update_route_member.sql b/layers/transportation_name/update_route_member.sql
index 178d94d..c8ddc75 100644
--- a/layers/transportation_name/update_route_member.sql
+++ b/layers/transportation_name/update_route_member.sql
@@ -1,13 +1,12 @@
-DROP TRIGGER IF EXISTS trigger_flag_transportation_name ON osm_route_member;
-
+CREATE TABLE IF NOT EXISTS ne_10m_admin_0_bg_buffer AS
+SELECT ST_Buffer(geometry, 10000)
+FROM ne_10m_admin_0_countries
+WHERE iso_a2 = 'GB';
 
 -- create GBR relations (so we can use it in the same way as other relations)
 CREATE OR REPLACE FUNCTION update_gbr_route_members() RETURNS void AS
 $$
-DECLARE
-    gbr_geom geometry;
 BEGIN
-    SELECT st_buffer(geometry, 10000) INTO gbr_geom FROM ne_10m_admin_0_countries WHERE iso_a2 = 'GB';
     DELETE FROM osm_route_member WHERE network IN ('omt-gb-motorway', 'omt-gb-trunk');
 
     INSERT INTO osm_route_member (osm_id, member, ref, network)
@@ -17,12 +16,41 @@ BEGIN
            CASE WHEN highway = 'motorway' THEN 'omt-gb-motorway' ELSE 'omt-gb-trunk' END
     FROM osm_highway_linestring
     WHERE length(ref) > 0
-      AND ST_Intersects(geometry, gbr_geom)
+      AND ST_Intersects(geometry, (SELECT * FROM ne_10m_admin_0_bg_buffer))
       AND highway IN ('motorway', 'trunk');
 END;
 $$ LANGUAGE plpgsql;
 
 
+CREATE OR REPLACE FUNCTION osm_route_member_network_type(network text, name text, ref text) RETURNS route_network_type AS
+$$
+SELECT CASE
+           WHEN network = 'US:I' THEN 'us-interstate'::route_network_type
+           WHEN network = 'US:US' THEN 'us-highway'::route_network_type
+           WHEN network LIKE 'US:__' THEN 'us-state'::route_network_type
+           -- https://en.wikipedia.org/wiki/Trans-Canada_Highway
+           -- TODO: improve hierarchical queries using
+           --    http://www.openstreetmap.org/relation/1307243
+           --    however the relation does not cover the whole Trans-Canada_Highway
+           WHEN
+                   (network = 'CA:transcanada') OR
+                   (network = 'CA:BC:primary' AND ref IN ('16')) OR
+                   (name = 'Yellowhead Highway (AB)' AND ref IN ('16')) OR
+                   (network = 'CA:SK:primary' AND ref IN ('16')) OR
+                   (network = 'CA:ON:primary' AND ref IN ('17', '417')) OR
+                   (name = 'Route Transcanadienne') OR
+                   (network = 'CA:NB:primary' AND ref IN ('2', '16')) OR
+                   (network = 'CA:PE' AND ref IN ('1')) OR
+                   (network = 'CA:NS' AND ref IN ('104', '105')) OR
+                   (network = 'CA:NL:R' AND ref IN ('1')) OR
+                   (name = 'Trans-Canada Highway')
+               THEN 'ca-transcanada'::route_network_type
+           WHEN network = 'omt-gb-motorway' THEN 'gb-motorway'::route_network_type
+           WHEN network = 'omt-gb-trunk' THEN 'gb-trunk'::route_network_type
+           END;
+$$ LANGUAGE sql IMMUTABLE
+                PARALLEL SAFE;
+
 -- etldoc:  osm_route_member ->  osm_route_member
 CREATE OR REPLACE FUNCTION update_osm_route_member() RETURNS void AS
 $$
@@ -31,31 +59,7 @@ BEGIN
 
     -- see http://wiki.openstreetmap.org/wiki/Relation:route#Road_routes
     UPDATE osm_route_member
-    SET network_type =
-            CASE
-                WHEN network = 'US:I' THEN 'us-interstate'::route_network_type
-                WHEN network = 'US:US' THEN 'us-highway'::route_network_type
-                WHEN network LIKE 'US:__' THEN 'us-state'::route_network_type
-                -- https://en.wikipedia.org/wiki/Trans-Canada_Highway
-                -- TODO: improve hierarchical queries using
-                --    http://www.openstreetmap.org/relation/1307243
-                --    however the relation does not cover the whole Trans-Canada_Highway
-                WHEN
-                        (network = 'CA:transcanada') OR
-                        (network = 'CA:BC:primary' AND ref IN ('16')) OR
-                        (name = 'Yellowhead Highway (AB)' AND ref IN ('16')) OR
-                        (network = 'CA:SK:primary' AND ref IN ('16')) OR
-                        (network = 'CA:ON:primary' AND ref IN ('17', '417')) OR
-                        (name = 'Route Transcanadienne') OR
-                        (network = 'CA:NB:primary' AND ref IN ('2', '16')) OR
-                        (network = 'CA:PE' AND ref IN ('1')) OR
-                        (network = 'CA:NS' AND ref IN ('104', '105')) OR
-                        (network = 'CA:NL:R' AND ref IN ('1')) OR
-                        (name = 'Trans-Canada Highway')
-                    THEN 'ca-transcanada'::route_network_type
-                WHEN network = 'omt-gb-motorway' THEN 'gb-motorway'::route_network_type
-                WHEN network = 'omt-gb-trunk' THEN 'gb-trunk'::route_network_type
-                END;
+    SET network_type = osm_route_member_network_type(network, name, ref);
 
 END;
 $$ LANGUAGE plpgsql;