Index pgRouting on PostgreSQL Introduction Installation Template Creation and Use Topological Structure Core Features Public Transit Implementation (Application Specific)

Why routing on PostgreSQL? PostGIS ships with a Shape file loader an dumper Various file types (Shape, MapInfo, DGN, GML,...) can be read, converted and inserted to a PostGIS database using the OGC libraries A PostGIS Feature Table can be used as data source for a growing variety of map and feature server software like UMN MapServer, GeoServer, uDGI, deegree, JUMP, etc... The data can be accessed using standard ODBC or JDBC connectors Several projects have evolved around PostGIS transforming and inserting geometries from highly specialized formats like SICAD C60, EDBS, DXF, WLDGE and many more

pgRouting :an PostgreSQL Extension pgRouting adds routing functionality to PostgreSQL. pgRouting is an extendible open-source library that provides a variety of tools for shortest path search as extension of PostgreSQL. Navigation for road networks requires complex routing algorithms that support turn restrictions and even time dependent attributes. Routing basically requires Network topology, which contains edges and nodes.

Core Features of pgRouting pgRouting provides functions for: -Shortest Path Dijkstra: routing algorithm without heuristics -Shortest Path A-Star: routing for large datasets (with heuristics) -Shortest Path Shooting-Star: routing with turn restrictions (with heuristics) (Extras) -Traveling Salesperson Problem (TSP) -Driving Distance calculation (Isolines)

pgRouting Installation On Ubuntu : # Add pgRouting launchpad repository sudo add-apt-repository ppa:georepublic/pgrouting sudo apt-get update # Install pgRouting packages sudo apt-get install gaul-devel \ postgresql-8.4-pgrouting \ postgresql-8.4-pgrouting-dd \ postgresql-8.4-pgrouting-tsp On Windows: Download pgRouting binary package from : load.html Copy Share folder from binary package to : C:/Program Files/ … / /lib/

Required Topological data structure Nodes : points with a geographic position. edges : represents connectivity of nodes, representing a polyline or multipolyline. Relations : between groups of nodes, edges and other relations which can be assigned certain properties. Tags can be applied to nodes, edges or relations and consist of name=value pairs.

pgRouting Template Creation and Use: To enable pgRouting functionality in a database, we need to run : pgRouting functions -routing_core.sql -routing_core_wrappers.sql -routing_topology.sql TSP functions -routing_tsp.sql -routing_tsp_wrappers.sql Driving Distance functions -routing_dd_wrappers.sql

pgRouting: Topology Calculation First we have to add source and target column, then we run the assign_vertex_id function...: -- Add "source" and "target" column ALTER TABLE ways ADD COLUMN "source" integer; ALTER TABLE ways ADD COLUMN "target" integer; -- Run topology function (eg.) assign_vertex_id(’ ’, float tolerance, ’ ’) SELECT assign_vertex_id(’ways’, , ’the_geom’, ’gid’);

Public Transit Implementation using pgRouting Data in-Use: ▫POI tables  Bus Stops  Malls and Cinema Halls  Hospitals.. etc ▫Road Network ▫Bus Routes

Without Change-Over from Source to Destination Route Finding

References: Setting up pgRouting postgresql-with-postgis/ 1/2 pgRouting Workshop pgRouting Documents PostGIS in Action