Dr. Richard Connors

Institute for Transport Studies, University of Leeds, UK

January 23, 2009, 11:15, Room GC C3 30 (click here for the map)

Aggregation and Complexity in Transport Network Models

Transport models comprise a representation of the network infrastructure, and of transport users who decide how, where and when to travel. Naturally, the models used to optimise micro-scale/short-term measures (e.g. timing of traffic lights), are different from those used when planning major infrastructure (e.g. increasing motorway capacity), or designing long term policy (e.g. for sustainable future transport systems). However, we should expect such models to somehow 'agree' with each other; transport network models on large spatial and temporal scales should be consistent with those commonly used for smaller scale, nearer term forecasting. In fact there is little understanding of what difference a change in scale makes to model predictions, how to connect current transport models across different scales of analysis and different data resolutions, and what it means for them to be consistent. In transport modelling, aggregation refers to the level of detail included in network and behavioural models, and the methods used to summarise characteristics of detailed models for larger scale analyses. For traffic flow dynamics on a single link, there is some theory on aggregating individual car-following models to give fluid flow PDEs and area speed-flow relationships. For transport networks there is no such theory of aggregation. A key challenge therefore is to establish theory and methods for the aggregation of network models; to connect existing models across different scales, and to provide aggregate representations of transport networks for large-scale, long-term analyses. In this lecture I will outline a new analytic method for network aggregation. With this in mind, I will consider how recent advances in the study of complex networks might be used in the large-scale, long-term analysis of transport networks.


Dr Connors gained his first degree in Mathematics (Oxford) and his PhD in Quantum Chaology (Bristol). This was followed by 3 years working as a MATLAB developer (Cambridge). In 2003 Dr Connors returned to academic research, joining the Institute for Transport Studies (Leeds). His current research concerns the representation of network infrastructure and human behaviour within transport network models across different scales of analysis, and the consistency of these mathematical formulations.