30 November 2015

1

Aarhus School of EngineeringAarhus University

PostGIS and QGIS for Congestion Modelling in

MegaCities

Agenda

• Introduction• Congestion Modelling• Istanbul Case• GIS tools

Introduction

• Anders Lehmann Associate Professor• M.Sc.EE from DTU• Pursuing a PhD in Computer Science• Funded by EcoSense

Congestion Modelling

• Route Choice• Economic model 

– Cost = travel time

• Equilibrium when all travelers have the same traveltime– Changing route would increase travel time

Traffic model• User Equilibrium

– All drivers have the shortest travel distance– All must have the same travel time

Congestion Modelling

• Find shortest routes– Routes consists of links, shared between routes

• Assign traffic to routes• Calculate new traveltimes due to the congestions on the link

• Look for new shortest routes• Reassign traffic the routes

Istanbul case

• Data from Open Street Map• Converted to form a topology• 300.000 road segments (bidirectional)• 2000 Origin Destination pairs• QGIS for visualization

Modelling of congestion in Istanbul

GIS tools• PostgreSQL

– PostGIS – main library for GIS– Pgrouting – shortest path based on cost

• Open Street Map– Map data in efficient format– Reliable

• QGIS– Visualisation– Direct connection to PostgreSQL– Active development

30 November 2015

1

Thank YouFor Your Attention

Supported by:• Det strategiske forskningsråd,• Sabanci university, Turkeys

Ruteplanlægning fra Nordsjælland til Københavns Lufthavn