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Abstract
In this paper a method is proposed to enhance traffic assignment process in traditional
travel demand forecasting models. In this method link delay is calculated as a function of
flow on that link as well as flow on adjacent links, using intersection delay calculations.
This method employs a combination of Frank-Wolf and the method of successive
averages to model multi-path vehicle assignment in a reasonable amount of
computational time, for small and medium size transportation networks.
Inclusion of volume-based intersection delays in regional planning models is not yet
widespread in practice. The objective of this paper is to consider the impact of volumebased
(dynamic) intersection delays on multi-path traffic assignments in medium size
transportation networks. The approach selected is designed to provide more realistic
results than those generated by models represents only link delays, due to considering
flows on other links. Convergence has been an issue in assignment models that use
intersection delay. Nevertheless, convergence has been observed in a reasonable amount
of time in our model.
The results of this paper suggest that intersection delay, as especially at unsignalized
intersections where delays at minor legs are highly dependent on volumes, result in
significantly different assignments. It has been also demonstrated that the model achieves
a higher levels of calibration and it is more sensitive to intersection level policies.