在交通量分配理论的研究中,均衡模型理论的发展备受瞩目。交通均衡问题通过给定的O/D对需求和成本函数,按照既定的路径选择标准来确定交通网络中的流量分配以及各种性能指标。这种方法论的核心在于,在交通均衡状态下,没有任何交通参与者可以通过单方面改变自己的路径选择来获得更好的出行时间或成本,进而使交通系统的效率和性能最大化。但在现实情况下,由于交通参与者行为的多样性以及交通网络的复杂性,使得均衡状态很难达到。本文定义了交通均衡的一种近似情况——${\varepsilon}$-均衡流,并验证了其存在性。同时,还引入了${\varepsilon}$-均衡流的一类适定性,并建立此适定性成立的充分条件。这为理解和解决交通均衡问题提供了新的理论工具和方法。
In the study of traffic assignment theory, the development of equilibrium model theory has attracted significant attention. The traffic equilibrium problem aims to determine the flow distribution and various performance metrics in a traffic network by using given O/D pair demand and cost functions, based on established path selection criteria. The core of this methodology lies in the fact that, under a traffic equilibrium state, no participant in the system can improve their travel time or cost by unilaterally changing their path choice, thereby maximizing the efficiency and performance of the traffic system. However, in reality, due to the diversity of traffic participants' behavior and the complexity of traffic networks, achieving a true equilibrium state is often challenging. This paper defines an approximate form of traffic equilibrium ${\varepsilon}$-equilibrium flow and verifies its existence. Additionally, it introduces a type of well-posedness for ${\varepsilon}$-equilibrium flow and establishes sufficient conditions for the validity of this well-posedness, providing new theoretical tools and methods for understanding and solving traffic equilibrium problems.
[1] Wardrop J G. Some theoretical aspects of road traffic research [J]. Proceedings of the Institution of Civil Engineers, 1952, 1(2): 325-378.
[2] Beckmann M J, McGuire C B, Winsten C B. Studies in the Economics of Transportation [M]. New Haven: Yale University Press, 1956.
[3] Smith M J. Existence, uniqueness and stability of traffic equilibria [J]. Transportation Research Part B: Methodological, 1979, 13(4): 295-304.
[4] Foulds L R, do Nascimento H A D, Iacer C A C, et al. A fuzzy set-based approach to origindestination matrix estimation in urban traffic networks with imprecise data [J]. European Journal of Operational Research, 2013, 231: 190-201.
[5] Mansour M A, Scrimali L. Hölder continuity of solutions to elastic traffic network models [J]. Journal of Global Optimization, 2008, 40: 175-184.
[6] Fang Y P, Hu R, Huang N J. Well-posedness for equilibrium problems and for optimization problems with equilibrium constraints [J]. Computers and Mathematics with Applications, 2008, 55(1): 89-100.
[7] Causa A, Raciti F. Lipschitz continuity results for a class of variational inequalities: A geometric approach [J]. Journal of Optimization Theory and Applications, 2010, 145: 235-248.
[8] Khanh P Q, Luu L M, Son T T M. Well-posedness of a parametric traffic network problem [J]. Nonlinear Analysis: Real World Applications, 2013, 14(4): 1643-1654.
[9] Hung N V. LP well-posed controlled systems for bounded quasi-equilibrium problems and their application to traffic networks [J]. Journal of Computational and Applied Mathematics, 2022, 401: 0377-0427.
[10] Florian M. Nonlinear cost network models in transportation analysis [J]. Mathematical Programming Study, 1986, 26: 167-196.
[11] Maonanti T L. Network design and transportation planning: Models and algorithms [J]. Transportation Planning Models, 1984, 18(1): 1-55.
[12] Xie C, Waller S T. Stochastic traffic assignment, lagrangian dual, and unconstrained convex optimization [J]. Transportation Research Part B: Methodological, 2012, 46: 1023-1042.
[13] Dontchev A L, Zolezzi T. Well-posed optimization problems [M]//Christensen L W. (ed.) Lecture Notes in Mathematics, New York: Springer-Verlag, 1993.
[14] Lucchetti R. Convexity and well-posed problems [M]//Jacobson M J, Williams H C. (eds) CMS Books in Mathematics, New York: Springer-Verlag, 2006.
[15] Tikhonov A N. On the stability of the functional optimization problem [J]. USSR Computational Mathematics and Mathematical Physics, 1966, 6(4): 28-33.
[16] Heydecker B G. On the definition of traffic equilibrium [J]. Transportation Research Part B: Methodological, 1986, 20(6): 435-440.