Congestion Pricing For Multimodal Transportation Networks Considering Equity Effects

Congestion pricing can alleviate traffic congestion via impose tolls on transportation facilitates to influence people’s travel decisions. Despite the success of pricing projects worldwide and growing government support, congestion pricing is still facing strong objection among the general public. While there are many reasons for the public opposition, much of this opposition centers on the perceived inequalities of congestion pricing. In order to improve the acceptability of congestion pricing among the general public, equity issues must be considered in designing congestion pricing schemes. Focusing on the topic of equity effects of congestion pricing, this dissertation contains the following contents:An in-depth investigation of the state-of-the-art of congestion pricing is provided. The congestion toll design problem is usually formulated as a bi-level mathematical program. The objective of the upper level problem is some system performance measures, while the lower level problem is the tolled user equilibrium problem. The asymmetric nature of travel costs in multimodal transportation networks imposes a great challenge for both model formulation and solution algorithm, which makes multimodal congestion pricing problem much more complicated than the single modal problem.Equity effects of congestion pricing are comprehensively analyzed and evaluated. The dimensions of congestion pricing include Horizontal equity, Vertical equity, Spatial equity, Generational equity, Market equity and Social equity. The measures of equity include range, variance, coefficient of variance, relative mean deviation, logarithmic variance, Gini coefficient. From the equity perspective, HOT lanes are the pricing strategy least likely to raise public concerns, while they are not as effective as more comprehensive congestion pricing. Pareto-improving congestion can improve the system performance without making any individual, including the government, worse off. This property makes Pareto-improving congestion pricing more attractive to the general public. Tradable credit schemes can be viewed as a revenue neutral congestion pricing schemes.A multiclass multimodal Pareto-improving pure rationing (MPI-PR) model was proposed. First, a Variational Inequality formulation of the multiclass multimodal user equilibrium model (MUE-PR) is proposed. The improved Manifold Suboptimization Algorithm is developed to solve the MPI-PR model, with the initial solution of the optimal solution of MUE-PR. Numerical results reveals that MPI-PR schemes are exist. The optimal aggregate link flows are unique, while the class-specific link flows are not unique. Under the MPI-PI policy, the mode split of low-VOT users are the same with that of high-VOT users.A Pareto-improving Rationing-Pricing hybrid policy (MHPI) with a discrete set of user classes on a multimodal transportation network is also proposed. It can be proved that the multiclass multimodal Pareto-improving hybrid scheme exists. Like the single-class hybrid policy, compared to the pure-rationing policy, users enjoy more flexibility by the hybrid policy. MHPI policy has a higher equity level than MPI-PR policy and MHPI-S policy. MHPI-S policy is a progressive policy which favors the low-VOT users, and it can improve the mode share of transit mode. From the efficiency perspective, multiclass Pareto-improving hybrid policies are less prevalent when compared to its single-class counterpart. The existence and effectiveness of Pareto-improving hybrid schemes not only depend on the network configuration but also on demographic features (e.g., VOT) of the population.This dissertation identifies the key factors that dominating the equity of congestion pricing, and explores the methods to improve the equity level of congestion pricing schemes. When considering users belong to a discrete set of classes, the distributional effects of congestion pricing on the choice of trip generation, mode and route can be captured, and then equity levels of congestion pricing can be obtained. Moreover, this dissertation applied congestion pricing on a multimodal transportation network, and combine congestion pricing with other travel demand management instruments, i.e. road space rationing, compares the equity and efficiency of different policies, which will rich the theorem system of congestion pricing, and provide good tools for the government and transportation authorities to design equitable congestion pricing schemes.