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This paper considers how the implementation of a tradable credit scheme (TCS) may be used to reduce road traffic and to contribute to the formation of liveable cities and global climate change commitments. The concept of applying TCS to individual road transport is familiar to transport researchers as a measure to regulate congestion and reduce transport-related emissions. Yet, it is not a strategy currently being considered by policy makers in the UK, despite the electrification of the road vehicle fleet and the associated loss of tax revenue presenting a rare opportunity to alter the economic instruments, which apply to road traffic. We consider how transport researchers can capitalise on this unique moment in transport history to shape transport policy. Our study uses qualitative methods, including a thematic analysis of semi-structured interviews with transport stakeholders and experts, in addition to a literature review and document analysis. Data analysis is inductive, permitting the formation of new ideas about the potential benefits of TCS and the barriers to the application of TCS to real-world policy. Building upon the results of TCS experiments and the results of our analysis, we propose a novel potential form of TCS combined with road pricing to maintain government revenue, which incentivises road users to decrease road vehicle kilometres travelled and reduce pollution and congestion. The proposal contributes to the discussion on the governance of road transport and taxation. [ABSTRACT FROM AUTHOR]

Private toll operators generally seek to maximize their profit while accounting for the re-routing and demand response of the road users and, in the case of competitive toll operation, the response of other toll operators. Traditionally, the literature assumes that toll operators act under perfect information or set up a game-theoretic approach to find the competitive equilibrium. This article takes a different approach. A system-dynamics approach is used to model both the users' route choice and demand response to changes in generalized cost and to model the toll operators' decision rules or toll-update strategies. Simple examples are used to demonstrate that the approach can lead to the traditional equilibrium solution under the assumption of perfect knowledge, but that other solutions may occur when operators use estimates of elasticities based on observed data. The solutions are shown to depend upon the frequency of the decision or change in toll level, and errors are related to the disequilibrium which is present as users respond to changes in toll levels. Finally, alternative toll-setting strategies are investigated whereby one operator may act aggressively to increase its share of the market while maximizing profit. This tactic is compared to the traditional Nash and Stackelberg solutions. [ABSTRACT FROM AUTHOR]

Abstract: This paper considers the use of ‘long-run cost functions’ for congested networks in solving second-best network problems, in which capacity and tolls are instruments. We derive analytical results both for general cost and demand functions and for specific functional forms, namely Bureau of Public Roads cost functions and constant-elasticity demand functions. The latter are also used in a numerical simulation model. We consider second-best cases where only a sub-set of links in a network is subject to tolling and/or capacity choice, and cases with and without a self-financing constraint imposed. We will demonstrate that, under certain assumptions, second-best long-run cost (or actually: generalized price) functions can be derived for most of the cases of interest, which can be used in an applied network model as a substitute for the conventional short-run user cost functions. Doing so reduces the dimensionality of the problem and should therefore be helpful in speeding up procedures for finding second-best optima. [Copyright &y& Elsevier]

Abstract: The performance of cordon pricing schemes is critically dependent on the location chosen for the cordon, and the toll imposed. Most cordon designs have been based on professional judgment, in the absence of guidance on the principles of efficient design. In this paper, a methodology based on Genetic Algorithms has been developed to identify the optimal location and toll level for one or more cordons, for a given objective function, with or without constraints on the design or required outcomes. To compare the performance of judgmental and optimal cordon designs, the method has been tested on a network of Edinburgh, with optimisation designed to achieve welfare maximisation with and without constraints on desired level of revenue and equity impact. The methodology is shown to generate appropriate solutions to all of these problems. The optimal single cordon achieves welfare benefits which are double those of the best judgmentally designed cordon. Constrained optima inevitably achieve lower benefits, but it is possible to design them so that this loss is minimised. [Copyright &y& Elsevier]