An Adaptive Bi-Level Gradient Procedure for the Estimation of Dynamic Traffic Demand

This paper presents an in-depth analysis of the bi-level gradient approximation approach for dynamic traffic demand adjustment and the development of new adaptive approaches. Initially, a comparison between the simultaneous perturbation stochastic approximation (SPSA), asymmetric design (AD), polynomial interpolation (PI) method, which was first proposed by authors in 2010-2011, and its second-order development is presented; then, a sensitivity analysis of the parameters of the SPSA AD-PI is reported; finally, some new advances of the estimation method based on an adaptive approach are proposed and evaluated on a real test network.