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A non-continuum approach to obtain a macroscopic model for the flow of traffic

Existing macroscopic models for the flow of traffic treat traffic as a continuum or
employ techniques similar to those used in the kinetic theory of gases. Spurious two-
way propagation of disturbances that are physically unacceptable are predicted by
continuum models for the flow of traffic. The number of vehicles in a typical section
of a freeway does not justify traffic being treated as a continuum. It is also important
to recognize that the basic premises of kinetic theory are not appropriate for the flow
of traffic. A model for the flow of traffic that does not treat traffic as a continuum
or use notions from kinetic theory is developed in this dissertation and corroborated
with traffic data collected from the sensors deployed on US 183 freeway in Austin,
Texas, USA.
The flow of traffic exhibits distinct characteristics under different conditions and
reflects the congestion during peak hours and relatively free motion during off-peak
hours. This requires one to use different governing equations to describe the diverse
traffic characteristics, namely the different traffic flow regimes of response. Such
an approach has been followed in this dissertation. An observer based on extended
Kalman filtering technique has been utilized for the purpose of estimating the traffic state. Historical traffic data has been used for model calibration. The estimated
model parameters have consistent values for different traffic conditions. These esti-
mated model parameters are then subsequently used for estimation of the state of
traffic in real-time.
A short-term traffic state forecasting approach, based on the non-continuum
traffic model, which incorporates weighted historical and real-time traffic information
has been developed. A methodology for predicting trip travel time based on this
approach has also been developed. Ten and fifteen minute predictions for traffic state
and trip travel time seem to agree well with the traffic data collected on US 183.

Identiferoai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/5913
Date17 September 2007
CreatorsTyagi, Vipin
ContributorsRajagopal, Kumbakonam, R, Swaroop, Darbha
PublisherTexas A&M University
Source SetsTexas A and M University
Languageen_US
Detected LanguageEnglish
TypeBook, Thesis, Electronic Dissertation, text
Format1584976 bytes, electronic, application/pdf, born digital

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