Fix #1091 by properly filtering one-way streets

gis/centreline/readme.md

@@ -14,7 +14,7 @@ The centreline data are used by many other groups in the City and it's often imp
 
 ## How It's Structured
 
-* The `gis_core.centreline_latest` Materialized View contains the latest set of lines with unique id `centreline_id`. These lines are undirected. All edges have _from_ and _to_ nodes, though this should not be taken to indicate that edges are directed. For a directed centreline layer, check out `gis_core.routing_centreline_directional` ([see more](#centreline-segments-edges))
+* The `gis_core.centreline_latest` Materialized View contains the latest set of lines with unique id `centreline_id`. These lines are undirected. All edges have _from_ and _to_ nodes, though this should not be taken to indicate that edges are directed. For a directed centreline layer, check out `gis_core.routing_centreline_directional` ([see more](#centreline-segments-edges)) which has the necessary schema to be used in pg_routing.
 * The `centreline_intersection_point_latest` Materialized View contains the latest set of unique intersections with unique id `intersection_id`. These are any location where two lines intersect, not strictly intersections in the transportation sense ([see more](#intersections-nodes))
 
 ## Where It's Stored
@@ -41,7 +41,7 @@ Currently we are including only the following types:
 
 #### Directionality
 
-Directionality of streets can be identified with the column `oneway_dir_code_desc`, distinguishing whether the segment is a one-way street. A two way street will be represented by a single segment. `oneway_dir_code` can be used to identify whether a segment is being drawn with the digitization or against, indicating vehicular traffic direction.
+Directionality of streets can be identified with the column `oneway_dir_code_desc`, distinguishing whether the segment is a one-way street. A two way street will be represented by a single segment (`oneway_dir_code = 0`). `oneway_dir_code` can be used to identify whether a segment is being drawn with the digitization (1) or against (-1), indicating vehicular traffic direction.
 
 #### Lineage
 

gis/centreline/sql/create_view_routing_centreline_directional.sql

@@ -1,39 +1,44 @@
 CREATE OR REPLACE VIEW gis_core.routing_centreline_directional AS
 
-SELECT 
+SELECT
     centreline_id,
     concat(row_number() OVER (), dir)::bigint AS id,
     source,
     target,
-    cost,
+    cost_length,
     geom
 
 FROM (
     SELECT
         centreline.centreline_id,
         centreline.from_intersection_id AS source,
         centreline.to_intersection_id AS target,
-        centreline.shape_length AS cost,
+        centreline.shape_length AS cost_length,
         centreline.geom,
-        0 as dir
+        0 AS dir
     FROM gis_core.centreline_latest AS centreline
+    WHERE centreline.oneway_dir_code >= 0 -- bi-directional and with digitization
 
     UNION
 
     SELECT
         centreline.centreline_id,
         centreline.to_intersection_id AS source,
         centreline.from_intersection_id AS target,
-        centreline.shape_length AS cost,
+        centreline.shape_length AS cost_length,
         st_reverse(centreline.geom) AS geom,
-        1 as dir
+        1 AS dir
     FROM gis_core.centreline_latest AS centreline
-    WHERE centreline.oneway_dir_code = 0) AS dup;
+    WHERE centreline.oneway_dir_code <= 0 /*bi-directional or against digitization*/
+) AS dup;
 
 ALTER TABLE gis_core.routing_centreline_directional OWNER TO gis_admins;
 
 COMMENT ON VIEW gis_core.routing_centreline_directional
-IS 'A view that contains centreline streets for routing, with duplicated rows for two-way streets and flipped geometries when necessary. A new id has been assigned to each centreline to distinguish duplicated lines.';
+IS '''A view that contains centreline streets for routing, with duplicated rows 
+for two-way streets and flipped geometries when lines were drawn against 
+digitization. A new id has been assigned to each centreline to distinguish 
+duplicated lines.''';
 
 GRANT SELECT ON TABLE gis_core.routing_centreline_directional TO bdit_humans;
 GRANT ALL ON TABLE gis_core.routing_centreline_directional TO gis_admins;