Metro systems : Construction, operation and impacts

Peer reviewedPublisher PD

Coordinated Transit Response Planning and Operations Support Tools for Mitigating Impacts of All-Hazard Emergency Events

This report summarizes current computer simulation capabilities and the availability of near-real-time data sources allowing for a novel approach of analyzing and determining optimized responses during disruptions of complex multi-agency transit system. The authors integrated a number of technologies and data sources to detect disruptive transit system performance issues, analyze the impact on overall system-wide performance, and statistically apply the likely traveler choices and responses. The analysis of unaffected transit resources and the provision of temporary resources are then analyzed and optimized to minimize overall impact of the initiating event

A CERCLA-Based Decision Model to Support Remedy Selection for an Uncertain Volume of Contaminants at a DOE Facility

The Paducah Gaseous Diffusion Plant (PGDP) operated by the Department of Energy is challenged with selecting the appropriate remediation technology to cleanup contaminants at Waste Area Group (WAG) 6. This research utilizes value focused thinking and multi attribute preference theory concepts to produce a decision analysis model designed to aid the decision makers in their section process. The model is based on CERCLA\u27s five primary balancing criteria, tailored specifically to WAG 6 and the contaminants of concern, utilizes expert opinion and the best available engineering, cost, and performance data, and accounts for uncertainty in contaminant volume. The model ranks 23 remediation technologies (trains) in their ability to achieve the CERCLA criteria at various contaminant volumes. A sensitivity analysis is performed to examine the effects of changes in expert opinion and uncertainty in volume. Further analysis reveals how uncertainty is expected to affect technology cost, time and ability to meet the CERCLA criteria. The model provides the decision makers with a CERCLA based decision analysis methodology that is objective, traceable, and robust to support the WAG 6 Feasibility Study. In addition, the model can be adjusted to address other DOE contaminated sites

A Study on Routing and Scheduling of Hazardous Materials in Railway Transportation

Railway transportation of hazardous materials including Toxic Inhalation Hazard, is crucial to North American economy. Although railway companies have favorable safety records in moving hazardous materials shipments, the possibility of spectacular events resulting from multicars incidents, however low, does exist, and the consequence can be potentially catastrophic in multiple fatalities. The rail disaster in Lac-Mégantic, Quebec, resulted in 47 fatalities and around $1.5 billion damages in 2013, is an example of low-probability high-consequence event. In this dissertation we aim at the development of analytical approaches considering the risk associated with hazardous materials in railway transportation. We study three versions of trip plan problems in the presence of hazardous materials, denoted as hazardous materials trip plan problems. In the first part of this dissertation we incorporate the blocking and train makeup decisions into the hazardous materials trip plan generation process, while limiting the total population exposures and environmental damages below the given thresholds. In evaluating the risk, we use aggregate measures, i.e., population exposures and environmental damages. We propose a non-linear mixed integer programming formulation for the considered problem. The solution of the model is NP hard. In order to solve realistic size problem instances, a heuristic method is proposed by decomposing the problem into freight-to-block and block-to-train assignment problems. We then investigate more realistic hazardous materials trip plan problems by relaxing some of the assumptions. In the second part of this dissertation we incorporate risk-spreading functions into trip plan generation process and train scheduling decisions. For each risk spreading function, we present a mathematical formulation and then we design a heuristic method to solve realistic size problem instances. We continue this study by introducing joint hazardous material trip plan and pricing problems. We also relax the assumption of the information of the customer requests are known in advance. Accordingly, we introduce different categories of customers with the definition of specific treatment for each of them including accept/reject basis and particular delivery and price regulations. In particular, we grouped customer requests into two classes as follows: (a) traditional customers, who sign long term contracts with the carrier, must be fulfilled by the carrier’s own services, and their delivery and price quotations are set in advance and not subject to change; and (b) irregular customers, who make request for a carload moves less frequently and on an irregular basis, maybe outsourced/rejected because of (1) lack of train capacities, (2) additional risk exceeds the given risk thresholds, or (3) service level requirements. We propose two-phase heuristic to solve the considered problem. In the first phase, we solve a deterministic transportation planning and train timetabling problem for the known demands in advance. In the second phase, an optimization-based problem is built and solved at the arrival of the new request. Eventually, the dissertation ends with conclusion and further research recommendations

Aeronautical Engineering. A continuing bibliography with indexes, supplement 156

This bibliography lists 288 reports, articles and other documents introduced into the NASA scientific and technical information system in December 1982

OPTIMIZATION OF RAILWAY TRANSPORTATION HAZMATS AND REGULAR COMMODITIES

Transportation of dangerous goods has been receiving more attention in the realm of academic and scientific research during the last few decades as countries have been increasingly becoming industrialized throughout the world, thereby making Hazmats an integral part of our life style. However, the number of scholarly articles in this field is not as many as those of other areas in SCM. Considering the low-probability-and-high-consequence (LPHC) essence of transportation of Hazmats, on the one hand, and immense volume of shipments accounting for more than hundred tons in North America and Europe, on the other, we can safely state that the number of scholarly articles and dissertations have not been proportional to the significance of the subject of interest. On this ground, we conducted our research to contribute towards further developing the domain of Hazmats transportation, and sustainable supply chain management (SSCM), in general terms. Transportation of Hazmats, from logistical standpoint, may include all modes of transport via air, marine, road and rail, as well as intermodal transportation systems. Although road shipment is predominant in most of the literature, railway transportation of Hazmats has proven to be a potentially significant means of transporting dangerous goods with respect to both economies of scale and risk of transportation; these factors, have not just given rise to more thoroughly investigation of intermodal transportation of Hazmats using road and rail networks, but has encouraged the competition between rail and road companies which may indeed have some inherent advantages compared to the other medium due to their infrastructural and technological backgrounds. Truck shipment has ostensibly proven to be providing more flexibility; trains, per contra, provide more reliability in terms of transport risk for conveying Hazmats in bulks. In this thesis, in consonance with the aforementioned motivation, we provide an introduction into the hazardous commodities shipment through rail network in the first chapter of the thesis. Providing relevant statistics on the volume of Hazmat goods, number of accidents, rate of incidents, and rate of fatalities and injuries due to the incidents involving Hazmats, will shed light onto the significance of the topic under study. As well, we review the most pertinent articles while putting more emphasis on the state-of-the-art papers, in chapter two. Following the discussion in chapter 3 and looking at the problem from carrier company’s perspective, a mixed integer quadratically constraint problem (MIQCP) is developed which seeks for the minimization of transportation cost under a set of constraints including those associating with Hazmats. Due to the complexity of the problem, the risk function has been piecewise linearized using a set of auxiliary variables, thereby resulting in an MIP problem. Further, considering the interests of both carrier companies and regulatory agencies, which are minimization of cost and risk, respectively, a multiobjective MINLP model is developed, which has been reduced to an MILP through piecewise linearization of the risk term in the objective function. For both single-objective and multiobjective formulations, model variants with bifurcated and nonbifurcated flows have been presented. Then, in chapter 4, we carry out experiments considering two main cases where the first case presents smaller instances of the problem and the second case focuses on a larger instance of the problem. Eventually, in chapter five, we conclude the dissertation with a summary of the overall discussion as well as presenting some comments on avenues of future work

Designing the Phytoremediation Landscape: Exploring phytoremediation of urban brownfields as a system and stage in designed and managed successional processes

The present day challenges facing the post-industrial city are economic reinvention, social equity, and environmental recovery. The urban mosaic of these places is vague and broken, and demands new and innovative solutions for the reclamation of vacant, abandoned, and contaminated landscapes that create a unification of economic, environmental, and cultural healing. A multi-scalar approach is proposed as a strategy for the integration of multiple components in multiple contexts. Particular focus is on the synthesis of community engagement and environmental remediation of these spoiled, derelict lands. Specifically, phytoremediation is explored as a solution for land reclamation, ecological and social recovery of parcel-scale urban open spaces. Discussion of how design intervention at multiple scales can be synthesized, the temporal dynamic of remediation, and the potential for integrating ecological natural attenuation and land-use activation simultaneously as a component of a staged and managed urban land succession, are explored. The problems and opportunities associated with the resurrection of the post-industrial city are vast and multifaceted. This project will propose strategies through design that attempt to merge the elements of sustainability into a new and replicable cultural, environmental and urban cleansing initiative