Pricing, Investment, and Network Equilibrium

Despite rapidly emerging innovative road pricing and investment principles, the development of a long run network dynamics model for necessary policy evaluation is still lagging. This research endeavors to fill this gap and models the impacts of road financing policies throughout the network equilibration process. The manner in which pricing and investment jointly shape network equilibrium is particularly important and explored in this study. The interactions among travel demand, road supply, revenue mechanisms and investment rules are modeled at the link level in a network growth simulator. After assessing several measures of effectiveness, the proposed network growth model is able to evaluate the short- and long-run impacts of a broad spectrum of road pricing and investment policies on large-scale road networks, which can provide valuable information to decision-makers such as the implications of various policy scenarios on social welfare, financial situation of road authorities and potential implementation problems. Some issues hard to address in theoretical analysis can be examined in the agent-based simulation model. As a demonstration, we apply the network growth model to assess marginal and average pricing scenarios on a sample network. Even this relatively simple application provides new insights into issues around road pricing that have not previously been seriously considered. For instance, the results disclose a potential problem of over-investment when the marginal cost pricing scheme is adopted in conjunction with a myopic profit-neutral investment policy.Transportation network equilibrium; Road growth; Pricing; Congestion toll; Investment; Transport policy analysis.

Economics of Road Network Ownership

This paper seeks to understand the economic impact of centralized and decentralized ownership structures and their corresponding pricing and investment strategies on transportation network performance and social welfare for travelers. In a decentralized network economic system, roads are owned by many agencies or companies that are responsible for pricing and investment strategies. The motivation of this study is two-fold. First, the question of which ownership structure, or industrial organization, is optimal for transportation networks has yet to be resolved. Despite several books devoted to this research issue, quantitative methods that translate ownership-related policy variables into short- and long-run network performance are lacking. Second, the U.S. and many other countries have recently seen a slowly but steadily increasing popularity of road pricing as an alternative to traditional fuel taxes. Not only is the private sector encouraged to finance new roads, this transition in revenue mechanism also makes it possible for lower-level government agencies and smaller jurisdictions to participate in network pricing and investment practice. The issue of optimal ownership is no longer a purely theoretical debate, but bears practical importance. This research adopts an agent-based simulator of network dynamics to explore the implications of centralized and decentralized ownership on mobility and social welfare, as well as potential financial issues and regulatory needs. Components of the simulator: the travel demand model, cost functions, and key variables of pricing and investment strategies, are empirically estimated and validated. Results suggest that road network is a market with imperfect competition. While there is a significant performance lag between the optimal strategy and the current network financing practice in the U.S. (characterized by centralized control, fuel taxes, and budget-balancing investment), a completely decentralized network suffers from issues such as higher-than-optimal tolls and over-investment. For the decentralized ownership structure, appropriate regulation on pricing and investment practices is necessary. Further analysis based on simulation comparisons suggests that with appropriate price regulation, a decentralized road economy consisting of profit-seeking road owners could outperform the existing centralized control, achieve net social benefits close to the theoretical optimum, and distribute a high percentage of welfare gains to travelers. Decentralized control is especially valuable in rapidly changing environments because it promptly responds to travel demand. These results seem to favor the idea of privatizing or decentralizing road ownership on congested networks. Further tests on real-world transportation networks are necessary and should make an interesting future study.Network economics, Modeling network dynamics, Road pricing, Transportation financing, Privatization.

Agent-Based Model of Price Competition and Product Differentiation on Congested Networks

Using consistent agent-based techniques, this research models the decision-making processes of users and infrastructure owner/operators to explore the welfare consequence of price competition, capacity choice, and product differentiation on congested transportation networks. Component models include: (1) An agent-based travel demand model wherein each traveler has learning capabilities and unique characteristics (e.g. value of time); (2) Econometric facility provision cost models; and (3) Representations of road authorities making pricing and capacity decisions. Different from small-network equilibrium models in prior literature, this agent-based model is applicable to pricing and investment analyses on large complex networks. The subsequent economic analysis focuses on the source, evolution, measurement, and impact of product differentiation with heterogeneous users on a mixed ownership network (with tolled and untolled roads). Two types of product differentiation in the presence of toll roads, path differentiation and space differentiation, are defined and measured for a base case and several variants with different types of price and capacity competition and with various degrees of user heterogeneity. The findings favor a fixed-rate road pricing policy compared to complete pricing freedom on toll roads. It is also shown that the relationship between net social benefit and user heterogeneity is not monotonic on a complex network with toll roads.Network dynamics, road pricing, autonomous links, privatization, price competition, product differentiation, agent-based transportation model

Vertical and horizontal tax competition in the transport sector

The purpose of this paper is to review the literature dealing with horizontal and vertical tax competition in the transport sector, taking into account the role of transport externalities. Our emphasis throughout is on tax competition between governments, not between private suppliers. For the various different settings (horizontal and vertical competition, parallel and serial networks), we discuss the relevance of tax competition and describe the type of results typically obtained. We further point out the relevance of different types of tax competition for transport policy in a European setting. Finally, we discuss the losses of non-cooperative behaviour of governments.

Incentive Regulatory policies: The Case of Public Transit Systems in France

We assess the empirical relevance of the new theory of regulation, using a principal-agent framework to study the regulatory schemes used in the French urban transport industry. Taking the current regulatory schemes as given, the model of supply and demand provides estimates for the firms’ inefficiency, the effort of managers, and the cost of public funds. It allows us to derive the first-best and second-best regulatory policies for each network and compare them with the actual situation in terms of welfare loss or gain. Fixed-price policies lie between fully informed and uninformed second-best schemes. Cost-plus contracts are dominated by any type of second-best contract. From these results, we may conjecture that fixed-price contracts call for better-informed regulators.Publicad

Road Pricing with Autonomous Links

This research examines road pricing on a network of autonomous highway links. By autonomous it is meant that the links are competitive and independent, with the objective of maximizing their own profits without regard for either social welfare or the profits of other links. The principal goal of the research is to understand the implications of adoption of road pricing and privatization on social welfare and the distribution of gains and losses. The specific pricing strategies of autonomous links are evaluated first under the condition of competition for simple networks. An agent-based modeling system is developed which integrates an equilibrated travel demand, route choice, and travel time model with a repeated game of autonomous links setting prices to maximize profit. The levels of profit, welfare consequences, and potential cooperative arrangements undertaken by autonomous links will be evaluated. By studying how such an economic system may behave under various circumstances, the effectiveness of road pricing and road privatization as public policy can be assessed.Network dynamics, road pricing, autonomous links, privatization, agent-based transportation model