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  • 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.
111

Business Strategies to Improve On-Time Deliveries and Profits in Southcentral Alaska

Leaver II, Donald Richard 01 January 2015 (has links)
Traffic congestion can cause late deliveries, decreased profits from vehicle fuel idling in traffic, and delayed distribution in tight delivery windows. The focus of this study was on developing strategies that business leaders could use to increase on-time deliveries. The conceptual frameworks for this case study were systems theory, traffic equilibrium theory, bathtub theory, and kinematic wave theory. Data were collected from semistructured interviews with 6 delivery service leaders from 3 delivery businesses in Southcentral Alaska. In addition, secondary data were collected from government information. Interview responses were coded to identify trends including delivery time, business activity, and amount of roadway congestion. Two major themes emerged from the interviews: time of day affecting when traffic congestion occurred, and limited alternate transportation routes causing congestion in Southcentral Alaska. The findings indicated that the best strategy to help reduce traffic congestion involved instituting toll optimization and high occupant vehicles lanes. The implications for effecting social change include how business leaders can help reduce traffic congestion using toll optimization, and how high occupant vehicle lanes could encourage Southcentral Alaskans to carpool.
112

Alleviating traffic congestion in Montreal's Champlain Bridge corridor : commuter rail or express bus?

Armstrong, Derek January 2005 (has links)
No description available.
113

Agent-based simulations in urban economics: Applications to traffic congestion and housing markets

Mc Breen, John 22 June 2009 (has links) (PDF)
Simulations have considerable potential for the analysis of the evolution of economics systems, a subject often neglected by mainstream economics where the focus is on static equilibria. This thesis investigates the potential of this approach in urban economics. The purpose is to examine how global phenomena emerge from the interactions of economic agents. This is a promising method as a classical economics, lacking the appropriate analytic tools, concentrates on the existence of equilibria and refrains from investigating their stability. This study demonstrates the potential of simulations in three models. Firstly, in a standard model of traffic congestion it is shown that the Nash equilibrium is unstable and cannot be reached dynamically. Secondly, it is shown that simulations of the formation of urban land rents, reproduce elements of the theoretical equilibrium, and also endogenous vacancies, which are an important real-world phenomenon. Thirdly, an agent-based model of the housing market, which reproduces important empirical phenomena such as price dispersion, non-zero search times and vacancies, has been developed. The model provides a basis for the exploration of the complex dynamics of this market.
114

Planning Container Drayage Operations at Congested Seaports

Namboothiri, Rajeev 19 May 2006 (has links)
This dissertation considers daily operations management for a fleet of trucks providing container pickup and delivery service to a port. Truck congestion at access points for ports may lead to serious inefficiencies in drayage operations, and the resultant cost impact to the intermodal supply chain can be significant. Recognizing that port congestion is likely to continue to be a major problem for drayage operations given the growing volume of international containerized trade, this research seeks to develop optimization approaches for maximizing the productivity of drayage firms operating at congested seaports. Specifically, this dissertation addresses two daily drayage routing and scheduling problems. In the first half of this dissertation, we study the problem of managing a fleet of trucks providing container pickup and delivery service to a port facility that experiences different access wait times depending on the time of day. For this research, we assume that the wait time can be estimated by a deterministic function. We develop a time-constrained routing and scheduling model for the problem that incorporates the time-dependent congestion delay function. The model objective is to find routes and schedules for drayage vehicles with minimum total travel time, including the waiting time at the entry to the port due to congestion. We consider both exact and heuristic solution approaches for this difficult optimization problem. Finally, we use the framework to develop an understanding of the potential impact of congestion delays on drayage operations, and the value of planning with accurate delay information. In the second half of this dissertation, we study methods for managing a drayage fleet serving a port with an appointment-based access control system. Responding to growing access congestion and its resultant impacts, many U.S. port terminals have implemented appointment systems, but little is known about the impact of such systems on drayage productivity. To address this knowledge gap, we develop a drayage operations optimization approach based on a column generation integer programming heuristic that explicitly models a time-slot port access control system. The approach determines pickup and delivery sequences with minimum transportation cost. We use the framework to develop an understanding of the potential efficiency impacts of access appointment systems on drayage operations. Findings indicate that the set of feasible drayage tasks and the fleet size required to complete them can be quite sensitive to small changes in time-slot access capacities at the port.
115

Real-time estimation of arterial performance measures using a data-driven microscopic traffic simulation technique

Henclewood, Dwayne Anthony 06 June 2012 (has links)
Traffic congestion is a one hundred billion dollar problem in the US. The cost of congestion has been trending upward over the last few decades, but has experienced slight decreases in recent years partly due to the impact of congestion reduction strategies. The impact of these strategies is however largely experienced on freeways and not arterials. This discrepancy in impact is partially linked to the lack of real-time, arterial traffic information. Toward this end, this research effort seeks to address the lack of arterial traffic information. To address this dearth of information, this effort developed a methodology to provide accurate estimates of arterial performance measures to transportation facility managers and travelers in real-time. This methodology employs transmitted point sensor data to drive an online, microscopic traffic simulation model. The feasibility of this methodology was examined through a series of experiments that were built upon the successes of the previous, while addressing the necessary limitations. The results from each experiment were encouraging. They successfully demonstrated the method's likely feasibility, and the accuracy with which field estimates of performance measures may be obtained. In addition, the method's results support the viability of a "real-world" implementation of the method. An advanced calibration process was also developed as a means of improving the method's accuracy. This process will in turn serve to inform future calibration efforts as the need for more robust and accurate traffic simulation models are needed. The success of this method provides a template for real-time traffic simulation modeling which is capable of adequately addressing the lack of available arterial traffic information. In providing such information, it is hoped that transportation facility managers and travelers will make more informed decisions regarding more efficient management and usage of the nation's transportation network.
116

Studies of traffic oscillations: a behavioral perspective

Chen, Danjue 30 May 2012 (has links)
Traffic oscillations, or simply stop-and-go waves, are a common phenomenon arising in congested traffic but still not well understood. This phenomenon causes broad adverse impacts to safety risk, fuel efficiency and greenhouse emission. To eliminate or reduce those impacts, understanding the cause and propagation mechanism is essential. This dissertation studied driving behavior in traffic oscillations with the objective to uncover the formation and propagation mechanism of traffic oscillations. This study establishes a behavioral car-following model, the Asymmetric Behavioral model, based on empirical trajectory data that is able to reproduce the spontaneous formation and ensuing propagation of traffic oscillations in congested traffic. By analyzing individual drivers' car-following behavior throughout oscillation cycles it is found that this behavior is consistent across drivers and can be captured by a simple model. The statistical analysis of the model's parameters reveals that driver' behavior during oscillation (i.e., reaction to oscillation) is strongly correlated with driver behavior before oscillations and it varies with the development stage of the oscillation. Simulation of the model shows that it is able to produce characteristics of traffic oscillations consistently with empirical observations. This study also unveils the generation mechanism of the traffic hysteresis phenomenon arising in traffic oscillations using the Asymmetric Behavioral model. It is found that the occurrence of traffic hysteresis is closely correlated with driver behavior when experiencing traffic oscillations. In the growth and fully-developed stage of traffic oscillations, drivers behave differently, which results in different distribution of hysteresis patterns. This research makes it possible to unveil new management and control strategies of traffic oscillations to improve traffic operation and to quantify the environmental and safety impacts of traffic oscillations. For example, it can be used to estimate the increase of greenhouse emission and decrease of fuel efficiency imposed by traffic oscillations. It can also be used to study the increase of accident rate.
117

Alleviating traffic congestion in Montreal's Champlain Bridge corridor : commuter rail or express bus?

Armstrong, Derek January 2005 (has links)
Car dependency has resulted in traffic congestion in the Champlain Bridge corridor between the South Shore and Montreal CBD. This thesis addresses the ongoing debate of whether an inflexible rail or more flexible express bus system is better suited for travel in the corridor. An exploratory analysis of commuters revealed dispersed work destinations, suburb-to-suburb commuting, and public transit constraints for car users, providing evidence that rail would not be an effective solution. Factors known to affect mode choice such as access walking time, cost, and number of transfers were quantified in a discrete choice model of mode choice by commuters in existing rail corridors in Montreal. The model was then applied to the Champlain Bridge corridor under the assumption of hypothetical rail implementation. The projected demand for rail was lower than current express bus use in the corridor, suggesting that there would be no justification in incurring the great expense of building a rail system to replace the current express bus system. Improvement of the established bus system would have greater potential to reduce car trips.
118

Campus emergency evacuation traffic management plan

Wu, Di, January 2009 (has links)
Thesis (M.S.)--Mississippi State University. Department of Civil and Environmental Engineering. / Title from title screen. Includes bibliographical references.
119

Analysis of traffic accidents in Gaborone, Botswana

Pego, Maeletso 03 1900 (has links)
Thesis (MSc (Geography and Environmental Studies))--University of Stellenbosch, 2009. / Botswana, a developing country in southern Africa, has not been spared the proliferating scourge of traffic accidents that is sweeping across the world. After HIV/AIDS, traffic accidents are the second largest cause of unnatural deaths in Botswana. The country is losing two per cent of its GDP every year to traffic accident costs. Furthermore, road safety is one of the major challenges the country will have to overcome in order to achieve its Vision 2016. This study investigates traffic accidents in Gaborone, the capital city of Botswana, for the years 2000 and 2005. The study analyses the characteristics of traffic accidents, examines their causes, maps the spatial distribution of traffic accidents for 2000 and 2005, and outlines the countermeasures government is instituting to curb accidents. The main data on traffic accidents used was extracted from the microcomputer accidents analysis package V5.0 (MAAP 5) obtained from the Traffic Police Division. Semi-structured interviews with transport and safety officers, traffic police and other stakeholders were conducted. The interviews were mainly about what government is doing to reduce the carnage caused by traffic accidents. Existing reports were also used as data sources. Microsoft Excel and ArcGIS 9.1 packages were used to do the analyses. The road casualties of drivers/riders are concentrated in the economically active age category of 15-64 years (95% for all casualties). In particular, the casualties are very high in the 20-39 age cohort with one third and three quarters of all casualties for 2000 and 2005 respectively. In addition, driver casualties by gender for the 20-39 age cohort show a high representation of males, namely 57% and 64% for 2000 and 2005 respectively.
120

Faktory regionálního růstu a rozvoje (se zaměřením na silniční dopravu) / Factors of regional growth and development (with focus on road transport)

ALINA, Jiří January 2011 (has links)
ALINA, Jiří. Factors of regional growth and development (with focus on road transport). České Budějovice, 2011. 141 pgs. Faculty of Economics. University of South Bohemia in České Budějovice. Thesis supervisor: doc. Ing. Ivana Faltová Leitmanová, CSc. This dissertational thesis deals with traffic congestion and its effects on growth and region development. The main objective of the thesis was to quantify negative effects and impacts on traffic systems in relation to region growth and development, where the traffic congestions interested in the first class roads. First, the author focused on the analysis of the traffic congestion, as the factor which is influencing regional growth and development. Further the value of travel time and calculation methods of the traffic congestion cost were researched. The calculation region was the South Bohemian Region and its first class roads. Subsequently, there were summarized factors characterizing the South Bohemian Region from the road transport view. In the last chapter, the traffic congestion cost was calculated for the South Bohemian region.

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