Analysing the design criteria of charging cordons

The idea of the efficient use of roads, which requires users to pay for the traffic congestion cost that they impose on an urban road network, is long established (Pigou, 1920; Walters, 1961). However, the gap between the constructive theory of road pricing and its real world application is significant due to the issue of public acceptance, technical feasibility, and the cost of implementation (Sharp, 1966; Verhoef et al, 1995; Stenman and Sterner, 1998; and Sumalee, 2000). Different charging regimes have been developed and studied including time or delay based charging, distance based charging, cordon or boundary based charging, and area based charging (Holland and Watson, 1978; May, 1992; Oldridge, 1990; Smith et al, 1994; and Ison, 1998). The cordon charging system is the core of the study in this paper where we are looking for criteria for the judgmental design of cordons. We use the term “judgmental cordon design” to describe the process to identify the best locations to levy the charges and specify the optimal charge levels based on professional judgment. This paper reviews the literature to identify design criteria in section 2, and then it describes a survey with six UK local authorities in section 3. Section 4 presents the results of the survey and finally section 5 discuss the results and draw the conclusions

Multi-concentric optimal charging cordon design

The performance of a road pricing scheme varies greatly by its actual design and implementation. The design of the scheme is also normally constrained by several practicality requirements. One of the practicality requirements which is tackled in this paper is the topology of the charging scheme. The cordon shape of the pricing scheme is preferred due to its user-friendliness (i.e. the scheme can be understood easily). This has been the design concept for several real world cases (e.g. the schemes in London, Singapore, and Norway). The paper develops a methodology for defining an optimal location of a multi-concentric charging cordons scheme using Genetic Algorithm (GA). The branch-tree structure is developed to represent a valid charging cordon scheme which can be coded using two strings of node numbers and number of descend nodes. This branch-tree structure for a single cordon is then extended to the case with multi-concentric charging cordons. GA is then used to evolve the design of a multi-concentric charging cordons scheme encapsulated in the twostring chromosome. The algorithm developed, called GA-AS, is then tested with the network of the Edinburgh city in UK. The results suggest substantial improvements of the benefit from the optimised charging cordon schemes as compared to the judgemental ones which illustrate the potential of this algorithm

A method to assess demand growth vulnerability of travel times on road network links

Many national governments around the world have turned their recent focus to monitoring the actual reliability of their road networks. In parallel there have been major research efforts aimed at developing modelling approaches for predicting the potential vulnerability of such networks, and in forecasting the future impact of any mitigating actions. In practice-whether monitoring the past or planning for the future-a confounding factor may arise, namely the potential for systematic growth in demand over a period of years. As this growth occurs the networks will operate in a regime closer to capacity, in which they are more sensitive to any variation in flow or capacity. Such growth will be partially an explanation for trends observed in historic data, and it will have an impact in forecasting too, where we can interpret this as implying that the networks are vulnerable to demand growth. This fact is not reflected in current vulnerability methods which focus almost exclusively on vulnerability to loss in capacity. In the paper, a simple, moment-based method is developed to separate out this effect of demand growth on the distribution of travel times on a network link, the aim being to develop a simple, tractable, analytic method for medium-term planning applications. Thus the impact of demand growth on the mean, variance and skewness in travel times may be isolated. For given critical changes in these summary measures, we are thus able to identify what (location-specific) level of demand growth would cause these critical values to be exceeded, and this level is referred to as Demand Growth Reliability Vulnerability (DGRV). Computing the DGRV index for each link of a network also allows the planner to identify the most vulnerable locations, in terms of their ability to accommodate growth in demand. Numerical examples are used to illustrate the principles and computation of the DGRV measure

Partition-based algorithm for estimating transportation network reliability with dependent link failures.

Evaluating the reliability of a transportation network often involves an intensive simulation exercise to randomly generate and evaluate different possible network states. This paper proposes an algorithm to approximate the network reliability which minimizes the use of such simulation procedure. The algorithm will dissect and classify the network states into reliable, unreliable, and un-determined partitions. By postulating the monotone property of the reliability function, each reliable and/or unreliable state can be used to determine a number of other reliable and/or unreliable states without evaluating all of them with an equilibrium assignment procedure. The paper also proposes the cause-based failure framework for representing dependent link degradation probabilities. The algorithm and framework proposed are tested with a medium size test network to illustrate the performance of the algorithm

Effective media-utility in learning

Thesis (Ph. D. in Education)--University of Tsukuba, (A), no. 2484, 2001.3.23Includes bibliographical reference

A congestion-pricing problem with a polycentric region and multi-class users: a continuum modelling approach

postprin

A Semilinear Wave Equation with Nonmonotone Nonlinearity

We prove that a semilinear wave equation in which the range of the derivative of the nonlinearity includes an eigenvalue of infinite multiplicity has a solution. The solution is obtained through an iteration scheme which provides a priori estimates

Positive Solutions for Classes of Multiparameter Elliptic Semipositone Problems

We study positive solutions to multiparameter boundary-value problems of the form -Δu = λg(u)+μf(u) in Ω u = 0 on ∂Ω where λ\u3e0, μ\u3e0, Ω⊆Rn; n≥2 is a smooth bounded domain with ∂Ω in class C2 and Δ is the Laplacian operator. In particular, we assume g(0)\u3e0 and superlinear while f(0

Reliable Network Design Problem: case with uncertain demand and total travel time reliability

In the reliable network design problem (RNDP) the main sources of uncertainty are variable demand and route choice. The objective is to maximize network total travel time reliability (TTR), which is defined as the probability that the network total travel time will be less than a threshold. A framework is presented for a stochastic network model with Poisson-distributed demand and uncertain route choice. The travelers are assumed to choose their routes to minimize their perceived expected travel cost following the probit stochastic user equilibrium condition. An analytical method is presented for approximation of the first and second moments of the total travel time. These moments are then fitted with a log-normal distribution. Then the design problem is tackled in which the analytical derivative of the TTR is derived with the sensitivity analysis of the equilibrated path choice probability. This derivative is then supplied to a gradient-based optimization algorithm to solve the RNDP. The algorithm is tested with a small network exampl