Integrative Freight Market Simulation

综合货运市场模拟（IFMS）试图描绘一个全面的货运运动，其中用户方，即，商品流动和物流方面，即，汽车旅行，被认为是。这一框架有可能克服基于商品的模型和车辆出行模型的局限性。基于商品的模型在考虑空车流量方面有很大的局限性（这是物流决策的结果），而车辆出行模型无法考虑货物的经济特性。IFMS是基于一个市场均衡公式，该公式描述了货运供应商之间的竞争，和一个路由问题的子集，以代表这些公司的行动时，拿起和交付货物。IFMS需要一个两级的方法，其中最高级别对应的估计提供的服务符合古诺-纳什均衡，而底层的重点是建设的图尔斯，满足古诺-纳什解决方案和剩余的系统约束，在一个大规模的模拟优化问题的背景下。系统约束分为：a）主要约束;和B）次要约束。主要制约因素是：（1）货运公司在市场均衡的情况下实现利润最大化;（2）用户要求得到满足，即，运输由每个区域生产并吸引到每个区域的商品。次要限制因素包括：III）所得到的出行链与已知的出行链数据一致;以及IV）所得到的商用车辆交通量与次级数据源一致，例如，交通数据。本项目将侧重于解决综合财务管理系统的最基本情况，同时考虑到主要制约因素（一和二），称为主要综合财务管理系统。这将需要开发解决方案的算法，获得路由模式是一致的古诺-纳什解决方案提供服务（基于假设的经济参数）和用户的要求。这将需要定义一套综合的、虽然有意义的测试案例，这些案例旨在代表不同规模和复杂程度的城市地区。这些病例将由多个数据集组成：1.分区系统; 2.相关经济参数的设置; 3.一组商用车辆运营商; 4.一组用户需求;以及，5.换句话说，将创建一组已知所有相关信息的合成案例。将要求货运业代表进行合作，以确保对测试案例进行有意义和现实的定义。他们的输入对于数据集3、4和5的创建尤其重要。将开发算法来解决主要IFMS并应用于这些测试用例。输入数据将由数据集1、2、3和4组成。算法的合理性和效率将通过确定它们能够如何估计商用车辆行程（数据集5）来评估。该奖项是根据交通运输行业工程探索性研究（ETI）计划征集而颁发的。

The Integrative Freight Market Simulation (IFMS) attempts to depict a comprehensive picture of freight movements, in which both the user side, i.e., commodity flows, and the logistic side, i.e., vehicle-trips, are considered. This framework has the potential to overcome the limitations of both commodity based models and vehicle-trip models. Commodity based models have great limitations in considering the flow of empty vehicles (which are the result of logistic decisions), while vehicle trip models are unable to take into account the economic characteristics of the cargoes.The IFMS is based on a market equilibrium formulation that depict the competition among freight transportation providers, and a subset of routing problems to represent the actions of these companies when picking up and delivering the goods. The IFMS entails a bi-level approach in which the top level corresponds to the estimation of the provision of service consistent with Cournot-Nash equilibrium, while the bottom level focuses on the construction of tours that satisfy the Cournot-Nash solution and the remaining system constraints, in a context of a large scale simulation-optimization problem. The system constraints have been classified in: a) Primary; and b) Secondary. The primary constraints are: I) freight transportation companies maximize profits in a context of market equilibrium; and II) the user requirements are met, i.e., the commodities produced by and attracted to each zone are transported. Secondary constraints are: III) the resulting trip chains are consistent with known trip chain data; and IV) the resulting commercial vehicle traffic is consistent with secondary data sources, e.g., ITS traffic data. This project will focus on solving the most basic case of IFMS, taking into account the primary constraints (I and II), referred to as the Primary IFMS. This would entail developing solution algorithms that obtain the routing patterns that are consistent with both the Cournot-Nash solution for the provision of service (based on assumed economic parameters) and the user requirements. This will entail the definition of a set of synthetic, though meaningful, test cases that are meant to represent urban areas of different sizes and levels of complexity. These cases will be comprised of a number of data sets: 1. zoning system; 2. set of relevant economic parameters;3. a set of commercial vehicle operators;4. a set of user requirements; and,5. a set of commercial vehicle trips.In other words, a set of synthetic cases for which all relevant information is known will be created. The collaboration of freight industry representatives will be requested to ensure a meaningful and realistic definition of the test cases. Their input is particularly important for the creation of data sets 3, 4, and 5. Algorithms will be developed to solve the Primary IFMS and applied to these test cases. The input data will be comprised of the data sets 1, 2, 3, and 4. The reasonableness and efficiency of the algorithms will be assessed by determining how well they are able to estimate the commercial vehicle trips (data set 5).This award is made under the Exploratory Research on Engineering the Transport Industries (ETI) program solicitation.