Dynamic Game Theoretic Models for Urban Freight Systems

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PROJECT SUMMARY: DYNAMIC GAME THEORETIC MODELS FOR URBAN FREIGHT SYSTEMSThe explicit consideration of freight transportation in the transportation planning and management processes is important for many reasons. On the positive side, an efficient freight transportation system is a sine equa non condition for economic competitiveness. On the negative side, there is a wealth of evidence indicating freight activity produces significant negative externalities that disproportionately affect disadvantaged communities. These negativity externalities are compounded by the combined pressures of economic globalization, user expectations and community concerns. As a consequence, the freight transportation systems of the 21st Century will have to cover a larger geographic area, be responsive to user needs and expectations, reduce the externalities produced, and do all of this in a context in which providing additional freight infrastructure will become more difficult and expensive. Simply put, the urban freight transportation system will have to do more with less. This immense challenge adds pressure to agencies that have to balance the conflicting objectives of multiple stakeholders. The complexity of freight movements and the lack of appropriate freight modeling methodologies only serve to heighten the challenge.Prior efforts to model urban freight systems have not considered the full impacts of information technologies. An example is current anecdotal evidence suggesting that the Internet and the e-commerce facilitated by it have increased the magnitude of truck-trips and changed their nature, with as yet un-quantified changes in social costs. That those net effects cannot be addressed within existing theories is a principal motivation for the proposed research to create a new family of urban freight models. The new models envisioned by the project team will directly treat the influence of the Internet and e-commerce, are explicitly dynamic, and account for the gaming behaviors of the multitudinous agents active on an urban freight network. This proposal describes a research plan that may lead to the first comprehensive theory of urban goods movements. The main research objective can be described as the strategic and general tactical modeling of prices, consumption levels, trip generation, capacity expansion, routes, schedules and designs for urban goods networks. This will be accomplished by creating a family of models. The most detailed and general models of this family will be dynamic stochastic hierarchical network games wherein the freight rights-of-way are shared with passenger traffic. The project team expects to show how urban goods movements and decisions appropriate to a within-day time scale can be integrated with network game-theoretic models involving day-to-day, week-to-week and year-to-year time scales. This will: (a) provide a more realistic depiction of the flow of both commodities and commercial vehicles, incorporating considerations of trip chains and empty trips than have not been previously possible; (b) enhance transportation modeling by adding realism to the freight supply-demand equilibration process during its disequilibrium phase; (c) improve the efficiency of carrier-specific traffic management; and (d) set the stage for a future research to decrease network-wide congestion by co-ordination of carrier-specific distributed traffic planning by embedding auctions in the dynamic game theoretic models developed in this study.