Heuristic Path-Enumeration Approach for Container Trip Generation and Assignment

A commonly ignored key ingredient in large-scale container network assignment is an impedance-driven geovisualization of optimal routes. In this study, we propose linear optimization models for both trip generation and trip assignment using dynamic programming on a GIS platform, which includes maps and data that are used to develop and generate trips. The proposed models are applied to intermodal railroad routes mostly in the United States. Dendritic optimal networks are figures visually depicting all optimal branches for the network

A Quantitative Framework for Assessing Vulnerability and Redundancy of Freight Transportation Networks

Freight transportation networks are an important component of everyday life in modern society. Disruption to these networks can make peoples’ daily lives extremely difficult as well as seriously cripple economic productivity. This dissertation develops a quantitative framework for assessing vulnerability and redundancy of freight transportation networks. The framework consists of three major contributions: (1) a two- stage approach for estimating a statewide truck origin-destination (O-D) trip table, (2) a decision support tool for assessing vulnerability of freight transportation networks, and (3) a quantitative approach for measuring redundancy of freight transportation networks.The dissertation first proposes a two-stage approach to estimate a statewide truck O-D trip table. The proposed approach is supported by two sequential stages: the first stage estimates a commodity-based truck O-D trip table using the commodity flows derived from the Freight Analysis Framework (FAF) database, and the second stage uses the path flow estimator (PFE) concept to refine the truck trip table obtained from the first stage using the truck counts from the statewide truck count program. The model allows great flexibility of incorporating data at different spatial levels for estimating the truck O- D trip table. The results from the second stage provide us a better understanding of truck flows on the statewide truck routes and corridors, and allow us to better manage the anticipated impacts caused by network disruptions.A decision support tool is developed to facilitate the decision making system through the application of its database management capabilities, graphical user interface, GIS-based visualization, and transportation network vulnerability analysis. The vulnerability assessment focuses on evaluating the statewide truck-freight bottlenecks/chokepoints. This dissertation proposes two quantitative measures: O-D connectivity (or detour route) in terms of distance and freight flow pattern change in terms of vehicle miles traveled (VMT). The case study adopts a “what-if” analysis approach by generating the disruption scenarios of the structurally deficient bridges in Utah due to earthquakes. In addition, the potential impacts of disruptions to multiple bridges in both rural and urban areas are evaluated and compared to the single bridge failure scenarios.This dissertation also proposes an approach to measure the redundancy of freight transportation networks based on two main dimensions: route diversity and network spare capacity. The route diversity dimension is used to evaluate the existence of multiple efficient routes available for users or the degree of connections between a specific O-D pair. The network spare capacity dimension is used to quantify the network- wide spare capacity with an explicit consideration of congestion effect. These two dimensions can complement each other by providing a two-dimensional characterization of freight transportation network redundancy. Case studies of the Utah statewide transportation network and coal multimodal network are conducted to demonstrate the features of the vulnerability and redundancy measures and the applicability of the quantitative assessment methodology

A Software-Agnostic Agent-based Platform for Modelling Emerging Mobility Systems

Due to the rapidly accelerated innovation cycle in transport and the emergence of new mobility concepts and technologies, public authorities, policy makers, and transport planners are currently in need of the tools for sustainable spatial and transport planning in the new mobility era. In this paper, a new modular, software-agnostic and activity-based spatial and transport planning platform is designed, i.e, the HARMONY Model Suite, that facilitates a novel integration of new and existing spatial and transport modelling tools. The paper focuses on describing the architecture of the platform and its passenger mobility simulation framework, which integrates -in an interoperable manner- activity-based models, mobility service management, and traffic simulation tools for evaluating new mobility system dynamics. The service management controllers for new mobility concepts are discussed in more detail with regards to their functionality and applicability

Capabilities of a Periodic Containerised Railfreight System in Germany

Based on an analysis of the developments to date, this article originates from and then substantiates long-discussed approaches of a fast, periodic unaccompanied combined rail freight transport network for Germany that corresponds to the target modal split. A four-stage scenario of a market entry is developed. The presented solution incorporates potentially novel aspects such as a network design based on the Deutschlandtakt Cargo integrated periodic timetable framework, the prospective quantity structures as of 2030, and a segmentation for a route-specific mix of two major shipping container types. The set of assessment indicators derived by the model allows to gain insights on the achievable capacities and service levels versus the addressable freight transport demand as well as consequential cost/benefit functions