The doctoral dissertations of the former Helsinki University of Technology (TKK) and Aalto University Schools of Technology (CHEM, ELEC, ENG, SCI) published in electronic format are available in the electronic publications archive of Aalto University - Aaltodoc.
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Dissertation for the degree of Doctor of Science in Technology to be presented with due permission of the Faculty of Engineering and Architecture for public examination and debate in Auditorium R1 at Helsinki University of Technology (Rakentajanaukio 4, Espoo, Finland) on the 12th of June, 2009, at 12 noon.
Overview in PDF format (ISBN 978-951-38-7341-7) [2614 KB]
VTT Publications 708, ISSN 1455-0849
Dissertation is also available in print (ISBN 978-951-38-7340-0)
Copyright © 2009 VTT Technical Research Centre of Finland
VTT Publications 708, ISSN 1235-0621
VTT-PUBS-708
TKK-DISS-2618
The principal aim of this study was to develop a method for making a short-term prediction model of traffic flow status (i.e. travel time and a five-step travel-speed-based classification) and test its performance in the real world environment. Specifically, the objective was to find a method that can predict the traffic flow status on a satisfactory level, can be implemented without long delays and is practical for real-time use also in the long term. A sequence of studies shows the development process from offline models with perfect data to online models with field data. Models were based on MLP neural networks and self-organising maps. The purpose of the online model was to produce real-time information of the traffic flow status that can be given to drivers. The models were tested in practice. In conclusion, the results of online use of the prediction models in practice were promising and even a simple prediction model was shown to improve the accuracy of travel time information especially in congested conditions. The results also indicated that the self-adapting principle improved the performance of the model and made it possible to implement the model quite quickly. The model was practical for real-time use also in the long term in terms of the number of carry bits that it requires to restore the history of samples of traffic situations. As self-adapting this model performed better than as a static version i.e. without the self-adapting feature, as the proportion of correctly predicted traffic flow status increased considerably for the self-adapting model during the online trial.
This thesis consists of an overview and of the following 5 publications:
Keywords: prediction, traffic flow status, travel time
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© 2009 Helsinki University of Technology