A Quadratic Interpolation MethodBased Algorithm for a Combined Travel Demand Model

Abstract:

he combined travel demand model (CTDM) combines the traveldestinationmoderoute choice based on the random utility theory.This model avoids the limitation of the conventional sequential fourstep procedure,and can be formulated as a nonlinear programming problem.By analyzing the partial linearization algorithm of CTDM,a quadratic interpolation method is proposed to obtain the approximated optimal step size.Comparison of the proposed algorithm with method of successive averages and bisection line search method in the classic Sioux Falls network confirms that the quadratic interpolation can converge faster and get better solution than the other two methods.

Key words:travel demand; combined model; quadratic interpolation; partial linearization