PGROUTING IN QGIS

How to tame your network - Ross McDonald @mixedbredie

Here be dragons

Get

Merge

Load

Update

Populate

Build

Analyse

Get lost

http://ghost.mixedbredie.net/pgrouting-with-strategi/

Get the data

Open Data Download

http://bit.ly/1I0Fwz3

Merge the roads

There’s a QGIS tool for that!

Select: Motorways, A roads, B roads, primary routes, minor roads and local streets

Vector > Data Management Tools > Merge Shapefiles to One…

Load into PostGIS

QGIS DB

Manager

Schema

Table

Primary key

Geometry

SRID

Spatial index

Update the network table

Add the required columns for pgRouting

Build the indices to make it fast

ALTER TABLE os_strategi.strat_rds

ADD COLUMN source integer,

ADD COLUMN target integer, etc., etc.

CREATE INDEX strat_rds_source_idx ON os_strategi.strat_rds USING btree(source);

Populate the network table

Start and end coordinates

Length costs

Speed (average driving / walking speeds)

Time = length / speed

Reverse costs

Build the network topology

Creates a node table used for start and end

points

SELECT pgr_createtopology(

'os_strategi.strat_rds', 0.001, 'geometry',

'gid', 'source', 'target');

Analyse the network

Checks for errors

MULTILINESTRING v LINESTRING

SELECT pgr_analyzegraph(

'os_strategi.strat_rds', 0.001, 'geometry',

'gid', 'source', 'target');

Get Lost© Crown copyright and database right 2015 100023404

Djikstra Shortest Path

© Crown copyright and database right 2015 100023404Strategi Network

Driving Distance (10min)

© Crown copyright and database right 2015 100023404Strategi Network

Alpha Shapes (isochrones)

© Crown copyright and database right 2015 100023404Strategi Network

Astar heuristic shortest path

Meridian2 Network© Crown copyright and database right 2015 100023404

Turn Restricted Shortest Path

Integrated Transport Network with RRI© Crown copyright and database right 2015 100023404

Geoserver WMS + TRSP

http://ghost.mixedbredie.net/combining-pgrouting-functions-in-openlayers3/

ITN+RRI=TRSP

'select to_cost, teid as

target_id,

feid||coalesce('',''||via,'''') as

via_path from

itn_turn_restrictions‘

Directed = true

Has reverse = true

Guides

http://anitagraser.com/?s=pgrouting

http://ghost.mixedbredie.net/pgrouting-with-

strategi/

http://ghost.mixedbredie.net/using-

pgrouting-with-os-meridian2/

http://ghost.mixedbredie.net/building-itn-for-

pgrouting/