• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 51
  • 3
  • 1
  • 1
  • Tagged with
  • 75
  • 75
  • 22
  • 18
  • 16
  • 14
  • 12
  • 11
  • 11
  • 10
  • 10
  • 9
  • 9
  • 8
  • 8
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Mega project analysis : a case study of the Gauteng Freeway Improvement Project

Parrock, Philip 04 1900 (has links)
Thesis (MA)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Mega projects have fascinated human beings for as long as history can remember. The urge to build something bigger and better than has ever been done before has always been a driving force behind the human race’s relentless pursuit of technological advancement. It is in this vein that mega projects have evolved over time, as methods of construction improved, so did the scale on which people could attempt new projects. The Channel Tunnel between England and France, the Hoover Dam in America and the Millau Viaduct in the French countryside are some of the biggest examples of infrastructure projects in the world and these are all unequivocally, mega projects. Costing at least $ 250 million and incorporating major technological challenges, mega projects continue to inspire and motivate artists and engineers alike. This thesis seeks to expand people’s understanding of the analysis of these mega projects. Mega project analysis is a field that has struggled to differentiate itself ordinary project analysis. The Gauteng Freeway Improvement Project (GFIP) and the associated e-tolling mega project will be analysed in this thesis. The framework for analysis will be provided by the work of Flyvbjerg, Bruzelius and Rothengatter (2003), who seek to analyse mega project success or failure based on three key indicators of economic sustainability, environmental concerns and the effect of public support. This thesis will use the indicators of economic sustainability and the effect of public support to determine whether the Gauteng Freeway Improvement Project (GFIP) can be viewed as a failed mega project or not. After an in-depth study of the data and material available, this descriptive and explanatory study shows that the GFIP and associated e-tolling mega project is indeed a failed mega project. This is because it has failed the analysis in both categories of economic sustainability and the effect of public support. / AFRIKAANSE OPSOMMING: Megaprojekte het al eeue lank die mens gefasineer. Die neiging van die mens om iets groter en beter te maak as wat al ooit gemaak was het nog altyd baie dryfkrag verskaf vir die mens se strewe na tegnologiese verbetering. Dit is met hierdie idee in gedagte dat megaprojekte met tyd verander het, soos wat boumetodes verbeter het, so ook het die grootte van projekte verander wat mense kon aanpak. Die Channel Tonnel tussen Engeland en Frankryk, die Hoover Dam in Amerika en die Millau Brug in die Franse platteland is voorbeelde van die grootste infrastruktuur projekte ter wêreld en hierdie is al drie, sonder enige twyfel, megaprojekte. Teen ‘n koste van ten minste $ 250 miljoen en met grootskaalse tegnologiese uitdaging, hou megaprojekte aan om vir beide kunstenaars en ingenieurs te motiveer en uit te daag. Hierdie tesis poog om mense se kennis van die analise van megaprojekte te verbreed. Megaprojek analise is ‘n veld wat al jare lank sukkel om verskille te bewerkstellig tussen homself en gewone projek analise. Die “Gauteng Freeway Improvement Project” (GFIP) en die verwante e-toll megaprojek sal geanaliseer word in hierdie tesis. Die raamwerk vir analise sal deur Flyvbjerg, Bruzelius en Rothengatter (2003) verskaf word, waar die outeurs poog om megaprojekte se sukses of mislukking te bepaal gebaseer op die sleutel aanwysers van ekonomiese volhoubaarheid, omgewingskwessies en die effek van openbare ondersteuning. Hierdie tesis sal gebruik maak van die ekonomiese volhoubaarheid en openbare ondersteuning aanwysers om te bepaal of die GFIP beskou kan word as a mislukte megaprojek of nie. Na ‘n in-diepte study van die data en materiaal beskikbaar, sal hierdie beskrywende en verduidelikende studie wys dat die GFIP en verwante e-toll megaprojek inderdaad ‘n mislukte megaprojek is, as gevolg daarvan dat die GFIP megaprojek analise aandui dat die megaprojek misluk het in beide die ekonomiese volhoubaarheid en publieke ondersteunings aanwysers.
62

An analysis of implementing open road tolling through the Gauteng freeway improvement project

Malahleha, Thabiso 03 1900 (has links)
Thesis (MDF)--Stellenbosch University, 2011. / The aim of this research report is to analyse the feasibility of Open Road Tolling (ORT) and its development in South Africa through the Gauteng Freeway Improvement Project (GFIP). ORT represents the next generation of Electronic Toll Collection (ETC) and this research report will assess to what extent the GFIP scheme is in line with other comparable tolling schemes; and is the institutional environment amenable to ORT. This will allow one to gauge the feasibility of the scheme and its potential for acceptability and success. The research report outlines the number of risks that come with an ORT scheme and these include amongst others collection risk, enforcement, technology, privacy and public acceptance. The success of the GFIP will largely be determined by how well these risks are mitigated and how the benefits can be marketed to the users. The literature review illustrates that whether road pricing schemes have failed to move forward, have been implemented, are currently under development, or still in the planning stage as a concept there are several consistent lessons and critical success factors one should apply when structuring a scheme. In the discussions with stakeholders, the following conclusions with regards to the feasibility of ORT and its development in South Africa were as follows: The factors which need to be addressed include political risk, effective marketing of the scheme to the public, obtaining political will and support, building trust between the scheme developer and the user, managing perceptions and acknowledgement of the fact that the scheme will need to prove itself over time. Inadequate demonstration of equity for the user along with poor communication would compromise public acceptance and the success of the scheme. Incorporating interoperability yields benefits in terms in terms of network externalities, the ability to use a single transponder for multiple tolling plazas and points, along with the potential for alternative uses for the transponder. ORT as a viable solution for the GFIP is feasible from a technical point in that it's the only way in which one can collect tolls from a high volume network and not cause disruptions in the flow of traffic. However, there are a number of persistent residual risks that SANRAL cannot entirely mitigate and some fall under the realm of political risk. While SANRAL has applied best practice principles in structuring the GFIP with the aim of providing value for money for the user and as far as possible tackling the issue of affordability, there are certain realities, such as the recent global financial crisis, the infrastructure backlog of the country, users paying for roads which were free and challenges with overall service delivery which place a strain on the legitimacy of the GFIP ORT scheme.
63

A dual approximation framework for dynamic network analysis: congestion pricing, traffic assignment calibration and network design problem

Lin, Dung-Ying 10 November 2009 (has links)
Dynamic Traffic Assignment (DTA) is gaining wider acceptance among agencies and practitioners because it serves as a more realistic representation of real-world traffic phenomena than static traffic assignment. Many metropolitan planning organizations and transportation departments are beginning to utilize DTA to predict traffic flows within their networks when conducting traffic analysis or evaluating management measures. To analyze DTA-based optimization applications, it is critical to obtain the dual (or gradient) information as dual information can typically be employed as a search direction in algorithmic design. However, very limited number of approaches can be used to estimate network-wide dual information while maintaining the potential to scale. This dissertation investigates the theoretical/practical aspects of DTA-based dual approximation techniques and explores DTA applications in the context of various transportation models, such as transportation network design, off-line DTA capacity calibration and dynamic congestion pricing. Each of the later entities is formulated as bi-level programs. Transportation Network Design Problem (NDP) aims to determine the optimal network expansion policy under a given budget constraint. NDP is bi-level by nature and can be considered a static case of a Stackelberg game, in which transportation planners (leaders) attempt to optimize the overall transportation system while road users (followers) attempt to achieve their own maximal benefit. The first part of this dissertation attempts to study NDP by combining a decomposition-based algorithmic structure with dual variable approximation techniques derived from linear programming theory. One of the critical elements in considering any real-time traffic management strategy requires assessing network traffic dynamics. Traffic is inherently dynamic, since it features congestion patterns that evolve over time and queues that form and dissipate over a planning horizon. It is therefore imperative to calibrate the DTA model such that it can accurately reproduce field observations and avoid erroneous flow predictions when evaluating traffic management strategies. Satisfactory calibration of the DTA model is an onerous task due to the large number of variables that can be modified and the intensive computational resources required. In this dissertation, the off-line DTA capacity calibration problem is studied in an attempt to devise a systematic approach for effective model calibration. Congestion pricing has increasingly been seen as a powerful tool for both managing congestion and generating revenue for infrastructure maintenance and sustainable development. By carefully levying tolls on roadways, a more efficient and optimal network flow pattern can be generated. Furthermore, congestion pricing acts as an effective travel demand management strategy that reduces peak period vehicle trips by encouraging people to shift to more efficient modes such as transit. Recently, with the increase in the number of highway Build-Operate-Transfer (B-O-T) projects, tolling has been interpreted as an effective way to generate revenue to offset the construction and maintenance costs of infrastructure. To maximize the benefits of congestion pricing, a careful analysis based on dynamic traffic conditions has to be conducted before determining tolls, since sub-optimal tolls can significantly worsen the system performance. Combining a network-wide time-varying toll analysis together with an efficient solution-building approach will be one of the main contributions of this dissertation. The problems mentioned above are typically framed as bi-level programs, which pose considerable challenges in theory and as well as in application. Due to the non-convex solution space and inherent NP-complete complexity, a majority of recent research efforts have focused on tackling bi-level programs using meta-heuristics. These approaches allow for the efficient exploration of complex solution spaces and the identification of potential global optima. Accordingly, this dissertation also attempts to present and compare several meta-heuristics through extensive numerical experiments to determine the most effective and efficient meta-heuristic, as a means of better investigating realistic network scenarios. / text
64

High occupancy toll lanes ignoring the potential for a environmental justice violation

Rodgers, Charner Lynn 05 April 2011 (has links)
In the US transportation system, environmental justice (EJ) issues are regulated by a variety of laws to ensure that all have fair treatment with respect to implementation of policies. If State Departments of Transportation adhere to all regulations properly but unconsciously, then an underlying negative impact on a community may still exist as a result of a newly implemented project. Since the implementation of High Occupancy Toll (HOT) lanes are fairly new, and since there have been numerous concerns from the public about their discriminatory nature, a decision support system is needed to identify potential EJ violations and issues when implementing a new or converted HOT lane. No prior model exists. The goal of this research is to assist state's Department of Transportation (DOT) in the early stages of the development of an HOT lane by developing a Potential Environmental Justice Violation Model that will help state agencies predict potential EJ violations before additional resources are invested into a project. By developing a model, this study identifies and classifies characteristic drivers of potential EJ violations related to communities' economic, social, or health and safety status. The Potential Environmental Justice Violation Model (PEJVM) allows state DOTs employees to define and evaluate the distribution of impacts in the relevant categories. The model provides a method for transforming complex qualitative and quantitative data about a project into a user-friendly format where the results can then be visualized using a spider radar diagram to determine the level of impact of each identified variable. The PEJVM was validated using two previous anonymous HOT case studies and demonstrated using the Interstate 85 Case Study in Atlanta, Georgia. This model offers a uniform method of identifying potential environmental justice violations when implementing a HOT lane. The model will also help inform state agencies of potential violations early in the planning stages of HOT lane projects so that the agency can solve any potential EJ issues before additional resources are invested.
65

A real options model for the financial valuation of infrastructure systems under uncertainty

Haj Kazem Kashani, Hamed 03 April 2012 (has links)
Build-Operate-Transfer (BOT) is a form of Public-Private Partnerships that is commonly used to close the growing gap between the cost of developing and modernizing transportation infrastructure systems and the financial resources available to governments. When assessing the feasibility of a BOT project, private investors consider revenue risk - which is stemmed from the uncertainty about future traffic demand - as a critical factor. A potential approach to mitigating the revenue risk is the offering of revenue risk sharing mechanisms such as Minimum Revenue Guarantee options by the government. In addition to Minimum Revenue Guarantee options, a mechanism known as Traffic Revenue Cap options may also be negotiated, which makes the government entitled to a share of revenue when it grows beyond a specified threshold. Financial valuation of investments in BOT projects should take into account uncertainty about future traffic demand, as well as Minimum Revenue Guarantee and Traffic Revenue Cap options. The conventional valuation methods including Net Present Value (NPV) analysis are not capable of integrating the uncertainty about future traffic demand in the valuation of BOT projects and properly pricing Minimum Revenue Guarantee and Traffic Revenue Cap options. Real options analysis can be used as an alternative approach to valuation of investments in transportation projects under uncertainties. However, the appropriate application of real options analysis to valuation of investments in transportation projects is conditioned upon overcoming specific theoretical challenges. Current real options models do not provide a systematic method for estimating the project volatility, which measures the variability of investment value. Existing models do not provide a method for calculating the market value of Minimum Revenue Guarantee and Traffic Revenue Cap options. Also, current models are not able to characterize the impact of Minimum Revenue Guarantee and Traffic Revenue Cap options on private investors' financial risk profile. The overarching objective of this research is to apply the real options theory in order to price Minimum Revenue Guarantee and Traffic Revenue Cap options under the uncertainty about future traffic demand. To achieve this objective, a real options model is created that characterizes the long-term traffic demand uncertainty in BOT projects and determines investors' financial risk profile under uncertainty about future traffic demand. This model presents a novel method for estimating the project volatility for real options analysis. This model devises a market-based option pricing approach to determine the correct value of Minimum Revenue Guarantee and Traffic Revenue Cap options. An appropriate procedure is created for characterizing the impact of Minimum Revenue Guarantee and Traffic Revenue Cap options on the investors' financial risk profile. The proposed real options model is applied to a BOT project to illustrate the valuation process. The limitations of the proposed real options model, as well as the barriers to its implementation, are identified and recommendations for future research are offered. This research contributes to the state of knowledge by presenting a new method for estimating the project volatility, which is required for the real options analysis of transportation investments. It also introduces a risk-neutral valuation method for pricing the market value of Minimum Revenue Guarantee and Traffic Revenue Cap options in BOT projects. The research also contributes to the state of practice by introducing a novel class of assessment tools for decision makers that characterize the investors' financial risk profile under uncertainty about future traffic demand. Proper methods for pricing of Minimum Revenue Guarantee and Traffic Revenue Cap options are useful to public and private investors, in order to avoid wasting capital in transportation projects.
66

Effect of high occupancy toll (HOT) lanes on mass vehicle emissions: an application to I-85 in Atlanta

Kall, David 10 July 2008 (has links)
High Occupancy Toll (HOT) lanes were recently proposed for I-85 in Atlanta as a way to relieve congestion and provide a reliable commute time for single occupant drivers that are willing to pay a toll. It is important to evaluate the air quality impacts of such a proposal to meet environmental regulations, such as the National Environmental Policy Act (NEPA) and Transportation Conformity Regulations. The goal of this study is to understand how vehicle mass emissions change as a result of implementing HOT lanes on I-85 in Atlanta . This is done by considering a number of factors affect mass vehicle emissions, such as vehicle activity, vehicle speeds, vehicle age distributions, and vehicle class distributions. These factors are incorporated into a base scenario, which models the current condition on I-85 with HOV lanes, and a future scenario, which models the implementation of HOT lanes on this corridor. The base scenario mainly uses data from a data collection effort by Georgia Tech during the summer of 2007 on the I-85 corridor, while the future scenario makes alterations to these data using information from other cities that have already implemented HOT lanes. The MOBILE-Matrix modeling tool, which was recently developed by Georgia Tech [16], was used to run the emissions analysis using the input factors from these data sources. This tool calculated mass emissions for five pollutants: HC, NOx, CO, PM2.5, and PM10. The results show very small increases in mass emissions for NOx, CO, PM2.5, and PM10, and very small decreases in mass emissions for HC. Therefore, the implementation of HOT lanes on I-85 in Atlanta is unlikely to violate the Transportation Conformity Rule. For NEPA purposes, this analysis could be used to make the case that air quality impacts are not significant, and therefore further detailed analyses are not required.
67

Transport economic regulatory intervention in the transport infrastructure : a public-private partnership exploratory study

Maluleka, Khulumane John 31 January 2008 (has links)
The aim of this study is to determine whether the introduction of a transport economic regulatory authority would serve as a valid intervention mechanism in the Public-Private Partnership of the transport infrastructure in South Africa. In order to achieve this objective, the study focused on the analysis of the concept of Public-Private Partnership, and how it has unfolded in a number of industrialised countries. Much attention was devoted in examining how the Public-Private Partnership arrangements followed by the studied countries influenced the current transport infrastructure management process in South Africa. To deal with the above, a host of macro-environmental variables were analysed in respect of their potential impact on the South African Department of Transport. The establishment of various agencies by the Department of Transport was seen as a consequence of the influence of the prevailing environmental forces. The outcome of the analysis revealed that a sustainable transport infrastructural development is a product of genuine partnership between the public and private sectors. Competition for the market and the significance of such competition in the transport infrastructure were outlined. The main goal of competition within the context of this study is to diffuse the economic power of the toll road industry and the protection of the individual's fundamental rights. The study also unearthed a need to deepen the talent and skills of both public and private sector officials as this would enable them to protect the citizens' right to make well-considered choices in the toll road industry. The study identified a need to establish a transport economic regulatory authority that would control the market dynamics of power relationships in the transport industry. Such a body should be creative and need to have regulatory oversight over transport infrastructure. / Transport Logistics & Tourism / D. Comm.
68

The financing of a nonpure public good : the case of roads

Naude, C. M. (Clifford Marnetz), 1965- 06 1900 (has links)
This dissertation is concerned with the financing of roads in terms of public finance economic theory. The theory of public goods is applied to the case of roads and it is concluded that roads possess significant elements of privateness and are therefore nonpure public goods. Given that roads are nonpure public goods, and that the market for roads has natural monopoly characteristics, it is proposed that user charges have a role to play in the financing of roads. Road user charging techniques such as licence fees, fuel levies, tolls, area licensing, parking charges and weight-distance charges are evaluated. The advantages of user charging versus tax earmarking and general fund financing are examined. A road financing system for South Africa is proposed, whereby National roads are financed by user charges, and Provincial and Local roads are financed partly by user charges and partly by general taxes. / Economics and Management Sciences / Thesis (M.Com.)--University of South Africa, 1996.
69

Application of value for money assessment in public-private partnerships in the road transport sector : a case of the N4 (East) toll road

Muvirimi, Nyasha 12 1900 (has links)
Thesis (MDF)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: The purpose of this research was to understand how value for money (‘VfM’), an important decision pillar in public procurement, is applied in South Africa, and compare the VfM regulated framework with other global practices in the United Kingdom, Canada, Australia, Singapore and Hong Kong. VfM is applied when deciding the most appropriate procurement method that utilises public funds in the most cost effective, equitable and transparent manner. Although VfM is vital in the public sector, it is one of the most misunderstood and controversial procurement aspects. The various actors in public procurement processes tend to complicate this key aspect due to their conflicting objectives in relation to a given project. Chief among these are the political influences on the public managers, which tend to manipulate the procurement choice. Consequently over the years, the VfM assessments performed before selecting a procurement method have not been publicly available, thereby increasing concern on whether VfM is achieved, particularly when involving the private sector through public-private partnership (‘PPP’) arrangements. The study explores the various components of VfM, which are the public sector comparator, risk allocation mechanisms, particularly for the road sector projects, discount rates and post project implementation monitoring systems. More importantly, the research analysed how these various aspects were assessed on procuring the N4 toll road. South African National Road Agency SOC Limited (‘SANRAL’), although it did not have the benefit of a PPP guideline as is the case now, it performed extensive feasibility studies and held a transparent procurement process before selecting the private sector party to the PPP. Interestingly, project that was pre-identified as a PPP procurement model and had political support from both the Mozambique and South African governments from inception in order to make it work. The comparative analysis of the South African PPP framework and the selected global PPP markets revealed that the local VfM guidelines were comparable in most aspects such as the PSC construction and risk management methodologies. However, the South African practices could be further improved with increased transparency incorporated in the procurement process such as the publication of the PPP contract once finalised – a practice common in the developed markets analysed. This will go a long way to increasing acceptance of the PPP procurement model in a market that is tainted with mistrust of same. There is need for the civil servants to be trained on the VfM assessment processes so that such analyses are not limited to PPP-type projects, but to conventionally-procured infrastructure projects for increased accountability and effective use of public funds.
70

Assessing the marginal cost of freeway congestion for vehicle fleets using passive GPS speed data

Wood, Nicholas Stephen 08 July 2010 (has links)
This thesis examines the marginal cost of congested travel to a variety of businesses by observing time spent in congestion and estimating excess labor costs based upon the relevant value of time. The fleets in the scoping study represented commercial deliveries of goods and services, government agencies, and transit systems. Observations on limited-access expressways within the 13-county Atlanta metropolitan region were used in the analysis. Vehicles were monitored by using a passive GPS assembly that transmitted speed and location data in real-time to an off-site location. Installation and operation during the observation period required no interaction from the driver. Over 217 hours of good freeway movement during 354 vehicle-days was recorded. Rates of delay, expressed as a unit of lost minutes per mile traveled, were calculated by taking the difference in speeds observed during congestion from an optimal free-flow speed of 45 mph and dividing that by the distance traveled per segment. The difference between the 50th and 95th percentile delay rates was used as the measure for travel unreliability. Daily average values of extra time needed per fleet vehicle to ensure on-time arrivals were derived, and the median buffer across all fleets was 1.65 hours of added time per vehicle. Weekly marginal costs per fleet vehicle were estimated by factoring in the corresponding driver wages or hourly operation costs (for transit fleets). Equivalent toll rates were calculated by multiplying the 95th percentile delay rate by the hourly costs. The equivalent toll per mile traveled was representative of an equal relationship between the marginal costs of congestion experienced and a hypothetical state of free-flow travel (under first-best rules of marginal cost pricing). The median equivalent toll rates across all fleets was $0.43 per mile for weekday mornings, $0.13 per mile for midday weekdays, $0.53 per mile for afternoon weekdays and $0.01 per mile for weekday nights and weekends.

Page generated in 0.0763 seconds