This study describes the use of a Direct Search (DS) meta-heuristic algorithm for solving the toll design problem, in terms of finding the optimum toll level, in private roads. The problem is formulated as a nonconvex, bilevel nonlinear mathematical program which seeks to maximize toll revenues while taking into account the travel responses of network users, through a multi-class stochastic use...

Pricing is one of the best tools to improve the efficiency of highly congested transportation networks. It has been shown that an optimal toll pattern can be determined by applying the welfare-economics principle of marginal pricing. Because implementing the marginal pricing solution to the toll optimization problem requires charging each arc of the network any real valued toll, which is not re...

This paper extends the notion of toll pricing and the toll pricing framework previously developed for fixed demand traffic assignment [4, 13] to the problem with elastic demand. The system problem maximizes net benefit to the network users [9, 20] and the user problem is the usual one of finding equilibrium with elastic demand. We define and characterize T , the set of all tolls for the user pr...

Recently a methodology for traac networks has been developed which extracts congestion toll sets such that the tolled user equilibrium is system optimal. Properties of toll sets, such as convexity, are investigated, as well as relationships with other problems. For a given toll set, various objectives can be deened and optimized with respect to the tolls. Examples include minimizing the total t...

The problem of determining optimal tolls established on a subset of arcs in a multicommodity capacitated transportation network is presented. The problem is formulated as a bilevel optimization problem where the upper level consists of an administrator who establishes tolls in some arcs of a network, while the lower level is represented by a group of users who travel along the shortest paths wi...

We consider a bilevel road pricing problem. The lower level models a traffic assignment problem, whereas the upper level represents a toll problem which has impact on the distribution of the users on the network. We investigate the structure of this problem and consider a special lower level objective function. We show that a solution algorithm [10] can be applied to the optimal value reformula...

The Toll family of transmembrane proteins participates in signaling infection during the innate immune response. We analyzed the nine Drosophila Toll proteins and found that wild-type Toll-9 behaves similar to gain-of-function Toll-1. Toll-9 activates strongly the expression of drosomycin, and utilizes similar signaling components to Toll-1 in activating the antifungal gene. The predicted prote...

In this paper, a dynamic model of road traffic congestion is presented, with an elastic overall demand for morning peak road usage, and with the congestion technology used being ‘flow congestion’. It is demonstrated that in such a case, the optimal time-varying toll should include a ‘flat’, time-invariant component when road users share the same desired arrival time. This has important conseque...