A Workshop to be held at Queen’s University Belfast
on Wednesday-Thursday, 15-16 September,2004.
“Modelling link flows and travel times for dynamic traffic assignment”.
Workshop theme
Several different approaches have been taken in the literature on modelling traffic flows on roadways
when travel demands and traffic flows are varying over time. Some of these link flow or travel time
models are more realistic or tractable or convenient than others, for use in modeling network flows
over time. Each form of link flow model is likely to result in somewhat different predictions for
network flows and travel times. It is thus important to consider questions such as
 which link flow or travel time models should be used, or in what circumstances (if at all) each is
appropriate,
 how much the differences in the models affects the predictions and hence the reliability or
credibility of the results,
 what are the minimum desirable properties for models of links flows or travel times, and
 whether there is any consensus regarding these questions? Also,
 what additional features are important or essential to include in link models, such as lane
changing or spillback?
Talks or papers at the workshop may address any or all of the above questions, or aspects of these, or
other relevant related questions posed by participants.
Talks or papers may consider various types of link flow or travel time model. For example, in socalled ‘analytic’ network models, link flows and travel times have typically been modeled using
simple ‘whole-link’ models, in which the link travel time depends on the link flow or volume. In
some models the links are divided into a travel part, with fixed travel times, and a ‘vertical’ queue or a
spillback queue at the exit end of the link. In others a cell-transmission (CTM) model has been used,
and in yet others (microsimulation) the movements of individual vehicles are simulated in detail.
For enquiries please contact Malachy Carey: contact details below.
---------------------------------------------------------------Prof Malachy Carey
School of Management & Economics
25 University Square, Queen's University
Belfast, Northern Ireland, BT7 1NN.
Tel (work): +44 (0)2890 245 133
Tel (home): +44 (0)2890 203 659
Fax:
+44 (0)2890 975 156
E-mail:
m.carey@qub.ac.uk
Internet:
http://www.qub.ac.uk/transport/
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