Thesis (M. Phil.)--University of Hong Kong, 1994. / Includes bibliographical references (leaves 191-205).

After reviewing land based freight growth trends nationally and internationally, this thesis discusses the main parameters governing fuel consumption, as well as past approaches in modelling road and rail energy consumption. Past work on comparing these two main modes is also reviewed here. The review included ways of estimating energy consumption of a complete freight task i.e., from origin to destination. Mathematical models estimating modal energy consumption are presented in this thesis. Modal energy consumption is a complex function to be approximated in practice due to numerous variables affecting their outcome. Energy demands are particularly sensitive to changes in vehicle characteristics such as mass and size; route parameters such as grade and curvature; traffic conditions such as level of congestion; and less sensitive to ambient conditions, such as temperature and altitude. There is a large set of energy estimation models available to transportation planners. Unfortunately, unless simple relationships are established for energy estimation and modal comparison, their application in freight movement planning and corridor development becomes computationally prohibitive. This thesis describes the development of a modal freight energy comparison tool to quantify the energy advantage from mode choice, corridor development and vehicle types and loading improvements. The thesis also describes the used modelling processes and the trade-offs between model complexity and data quality. The tool developed in this thesis is based on well established relationships between energy consumption and traffic flow, route and vehicle operating characteristics for road freight movement. The rail freight component was developed from equations of motion together with parameters obtained from past studies. The relationships have been enhanced to fit the purpose of corridor level comparative analysis. The comparison tool has been implemented using a spreadsheet based approach developed specifically to calculate the total door to door energy consumption for given task options. A series of linked sheets enable the user to: specify all necessary inputs; estimate road and rail energy by trip segment. The outputs consist of trip segment energy demand and total energy efficiency of each option. A case study approach, for aiding in model development and testing, is presented. Toowoomba second range crossing in Southern Queensland, Australia (section between below Postman's Ridge and Gowrie Junction) was selected. Four options considered include existing and proposed road and rail corridors. The existing rail and road corridors could be taken as a typical poor case, with very high grades and sharp curvatures. The proposed new road section has a relaxed curvature and gradient. The section of proposed rail corridor, under consideration here, still contains a high grade section. However, the proposed track length is considerably shorter than the base-case. The new proposed train alignment was found as the most efficient mode and the existing trains as the least efficient mode when measured based on absolute expected fuel gain (litres/tonnage of freight moved). This could be attributed to the improvement in curvature and load carrying capacity. However, when the options are compared in terms of litres/1000 NTK, the new train option did not show a significant advantage. Furthermore, the developed model was applied on some simulated cases to test the functionality of other aspects of the model. The total door-to-door energy consumption and the efficiency were compared for all the simulated cases. It showed that the energy efficiency of scenarios varies exponentially with the variation in the ratio of road pickup and delivery legs to the rail line-haul length. In general, energy efficiency of the intermodal options was found to be better unless the best case of the road and the worst case of intermodal option was compared. The modelling approaches presented in the thesis and the comparison model developed in this study could be used for several purposes namely: to assess the energy (and hence greenhouse gas) implications of specific modal freight movements; to aid in the economic and environmental evaluation of transport options; and to assess the potential for energy efficiency gains from vehicle and infrastructure improvements. A number of suggested improvements to the model are also discussed.

published_or_final_version / Transport Policy and Planning / Master / Master of Arts

published_or_final_version / Transport Policy and Planning / Master / Master of Arts

published_or_final_version / abstract / Transport Policy and Planning / Master / Master of Arts in Transport Policy and Planning

published_or_final_version / Transport Policy and Planning / Master / Master of Arts in Transport Policy and Planning

This work presents two mechanisms for modeling alliance formation between leader carriers in a freight network for more efficient utilization of their resources: partial collaboration and complete collaboration. The performance of these alliance formation mechanisms is compared against the no collaboration case for various network topologies and demand levels. In the partial collaboration case, each leader carrier first maximizes his individual profits and leases out the residual capacity to other carriers. In the complete collaboration case all leader carriers join together to maximize the profit of the alliance. The profits are then distributed among the alliance members using the Shapley value principle. Numerical tests reveal that the topology of the network and the demand levels play an important role in determining the profits from each collaboration mechanism. It was also inferred that each of these factors also play a major role in determining the best collaboration strategy. / text

M.Phil.

Freight transportation is a significant component of the nation’s economy. However, the augmented volume of the freight movements contributed to continuously increasing congestion on the urban road networks, that affects the timeliness and reliability of freight transportation. In addition, congestion has a negative impact on the transit operations as well. Various studies conducted on multi-modal corridors recognized the importance of the simultaneous performance of freight and transit operations. Thus, Intelligent Transportation System (ITS) components, such as Freight Signal Priority (FSP) and Transit Signal Priority (TSP), present traffic operations strategies "shaped" to give priority, reduce delay and travel time, and overall improve the performance of freight and transit movements, respectively. The primary objective of the thesis refers to evaluate possible improvements in freight mobility, while sustaining good transit services and minimizing congestion on the multi-modal corridor, through simultaneous implementation of the FSP and the TSP. The effectiveness of the newly established criteria was evaluated through real-world case study on a micro-simulation platform. The results showed significant improvements on all the vehicle movements. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2019. / FAU Electronic Theses and Dissertations Collection

Air freight sector has been a growing market worldwide for many years. The rapid growth of scheduled freight aircraft services in particular has been a remarkable feature of the international airline industry during the past decades. Air freight traffic has grown faster than passenger traffic and the production of goods has become more dependent upon air freight services that link global supply chains together. Air transportation is useful when the goods must be delivered quickly and it also allows for more flexible hub-and-spoke networking structures, which are able to offset some of the problems of indirect flows. The concept of developing regional air-cargo centres can be seen from many different perspectives. The most important factors in airport location selection are connectivity to existing road and rail transport networks and current or potential freight traffic volumes. Right location allows firms to develop their own resources, consolidate their competitive position and nurture their growth. Once the company has located it is hard to relocate, so that is why the location decision has to be made carefully. Purpose: The main purpose of this thesis was to reveal the key factors, either positive or negative, which can affect the decision of air freight operators to relocate their express services to smaller airports.   Methodology: The chosen method for this thesis was the mono method because the data collection technique was qualitative. Based on that interviews, the authors finalized their topic and their research questions and built question lists, one for the Jönköping airport (Axamo), one for the companies that already operate in Jönköping airport and one for companies that do not operate there. The authors decided to have semi-structured interviews with all the interviewees in order to cover the different themes of their research.   Findings: The main findings from analysing the empirical data revealed that there are many different positive and negative factors that can affect the decision making for relocation of freight operators. The most important that were identified concern the airport’s infrastructure, location, quality of provided services, number of passenger flights and price policy. Moreover, the weather conditions at the region, the customers’ demand and connectivity with road and rail networks are also very influential.