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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.
91

Evaluation of traffic simulation models for work zones in the New England area

Khanta, Pothu Raju, January 2008 (has links)
Thesis (M.S.C.E.)--University of Massachusetts Amherst, 2008. / Includes bibliographical references (p. 71-72).
92

Public bus services versus congestion and pollution in Lima and Callao / Transporte público de buses versus congestión y contaminación en Lima y Callao

Martínez Espinal, Manuel 10 April 2018 (has links)
This study measures the influence of public bus services on traffic congestion and environmental pollution in Lima and Callao. The effect of the flow of buses on the transportation network is measured by way of a dynamic traffic assignment program, Dynasmart. The database is constructed on the basis of the 2005-2025 Master Plan. To this end, the transportation network is verified using Google Earth, and field measurements of capacity, speed, and volume- relay functions to describe traffic congestion are used. The flow of buses is calculated using the Emme3 program. Origin-destination matrices are calculated for each hour based on the 24-hour origindestination matrix from the Master Plan. In the case of congestion, both the exact and the maximum influence of the flow of buses are measured, and the case of segregating a traffic lane for a Rapid Bus System—a much-discussed topic—is also considered. In the case of pollution, the exact influence of the flow of buses is used to measure fuel consumption and pollutant emissions for the option of reducing public bus services as well as a further five options, including the implementation of a Rapid Bus System featuring gas-powered buses. It is found that halving the size of the bus fleet increases the speed of the transportation network by between 2 and 7% per day, and between 9 and 14% until 11 am, and yields 46% of the benefits of promoting clean fuels and inspection and maintenance; that is, that this measure is of limited worth in reducing congestion, and should not be considered a priority means of alleviating pollution. / Se mide la influencia del transporte público de buses sobre la congestión vehicular y sobre la contaminación ambiental de Lima y Callao. Se modela el efecto de los flujos de buses sobre la red de transporte mediante un software de asignación dinámica de tráfico Dynasmart. Se construye la base de datos sobre el Plan Maestro 2005-2025. Para ello, se verifica la red de transporte por Google Earth, y se utilizan mediciones de campo sobre capacidad, velocidad, y funciones volumen-demora que describen la congestión vial. Se calculan los flujos de uses con el software Emme3. Se construyen las matrices origen-destino por cada hora a partir de la matriz origendestino de 24 horas del Plan Maestro. En el caso de la congestión, se mide una influencia exacta y otra máxima de los flujos de buses, y también el caso de segregar un carril de vía para un sistema de buses rápidos, un tema frecuente de discusión. En el caso de la contaminación, se utiliza la influencia exacta de los flujos de buses para medir consumo de combustible y emisión de contaminantes para la alternativa de reducción de buses de transporte público y otras cinco alternativas más, entre ellas la implementación de un sistema de buses rápidos con buses a gas. Se obtiene que, reducir la flota de buses a la mitad, incrementa la velocidad de la red de transporte entre 2 y 7% diario y entre 9 y 14% a las 11 am, y que produce un 46% de los beneficios de promover combustibles limpios e inspección como mantenimiento; es decir, que esta medida es poco efectiva en reducir la congestión y que su prioridad debiera reducirse en aliviar la contaminación.
93

The feasibility of a congestion charge for Cape Town central business district from a traffic engineering perspective

Mohamed, Samantha Ann January 2008 (has links)
Thesis (MTech (Civil Engineering))--Cape Peninsula University of Technology, 2008. / There is an ever increasing need to introduce travel demand measures as the ability to construct new and upgrade existing roads to accommodate additional traffic volumes decreases. The City of Cape Town, hereinafter referred to as the City, has forecasted that traffic in the city could continue to increase by two and a half percent per year. To mitigate against the increased traffic volumes, the City is proposing a number of travel demand strategies, including a park and-ride facilities and high occupancy vehicle initiatives in the short term. The City’s draft travel demand management strategy identifies congestion charging as a measure more possible implementation in the medium term. This study investigates the feasibility of introducing a congestion charge from a traffic engineering perspective. This entails determining if there could be a reduction in traffic entering the Central Business District, what type of congestion charge is most suited for Cape Town and what type of technology is most appropriate at this point in time. In determining the type of charge and technology for introduction in Cape Town, international experience and trials were drawn upon in terms of case studies and research completed. These included developed and developing cities that had either introduced a congestion charge or considered it. To determine the potential level of traffic reduction, transportation elasticities for road pricing/congestion charging were used. This method of calculating the traffic reduction has been used on similar studies and provides a reasonable indication of the potential percentage reduction which could be achieved. The elasticities were based on post-implementation studies undertaken in cities which had introduced a congestion charge or road user pricing. For this study, elasticities between -0.1 and -0.5 were used. The study found that of the types of congestion charging available, a simple cordon charge, around the central business district (CBD) was most feasible. A cordon area would be more appropriate due to the small charge area involved, the flexibility that it allows and because it does not need to be visually intrusive in terms of roadside and enforcement equipment. The location of the cordon area also allows the key roads around the CBD to become the bypass route for vehicles that currently pass through the area. In terms of the charge payment system, it was found that presently, a manual payment system would be more appropriate for the city than a tag and beacon system.
94

Harnessing Big Data for the Sharing Economy in Smart Cities

Shou, Zhenyu January 2021 (has links)
Motivated by the imbalance between demand (i.e., passenger requests) and supply (i.e., available vehicles) in the ride-hailing market and severe traffic congestion faced by modern cities, this dissertation aims to improve the efficiency of the sharing economy by building an agent-based methodological framework for optimal decision-making of distributed agents (e.g., autonomous shared vehicles), including passenger-seeking and route choice. Furthermore, noticing that city planners can impact the behavior of agents via some operational measures such as congestion pricing and signal control, this dissertation investigates the overall bilevel problem that involves the decision-making process of both distributed agents (i.e., the lower level) and central city planners (i.e., the upper level). First of all, for the task of passenger-seeking, this dissertation proposes a model-based Markov decision process (MDP) approach to incorporate distinct features of e-hailing drivers. The modified MDP approach is found to outperform the baseline (i.e., the local hotspot strategy) in terms of both the rate of return and the utilization rate. Although the modified MDP approach is set up in the single-agent setting, we extend its applicability to multi-agent scenarios by a dynamic adjustment strategy of the order matching probability which is able to partially capture the competition among agents. Furthermore, noticing that the reward function is commonly assumed as some prior knowledge, this dissertation unveils the underlying reward function of the overall e-hailing driver population (i.e., 44,000 Didi drivers in Beijing) through an inverse reinforcement learning method, which paves the way for future research on discovering the underlying reward mechanism in a complex and dynamic ride-hailing market. To better incorporate the competition among agents, this dissertation develops a model-free mean-field multi-agent actor-critic algorithm for multi-driver passenger-seeking. A bilevel optimization model is then formulated with the upper level as a reward design mechanism and the lower level as a multi-agent system. We use the developed mean field multi-agent actor-critic algorithm to solve for the optimal passenger-seeking policies of distributed agents in the lower level and Bayesian optimization to solve for the optimal control of upper-level city planners. The bilevel optimization model is applied to a real-world large-scale multi-class taxi driver repositioning task with congestion pricing as the upper-level control. It is disclosed that the derived optimal toll charge can efficiently improve the objective of city planners. With agents knowingwhere to go (i.e., passenger-seeking), this dissertation then applies the bilevel optimization model to the research question of how to get there (i.e., route choice). Different from the task of passenger-seeking where the action space is always fixed-dimensional, the problem of variable action set emerges in the task of route choice. Therefore, a flow-dependent deep Q-learning algorithm is proposed to efficiently derive the optimal policies for multi-commodity multi-class agents. We demonstrate the effect of two countermeasures, namely tolling and signal control, on the behavior of travelers and show that the systematic objective of city planners can be optimized by a proper control.
95

DEVELOPMENT OF GUIDELINES FOR IMPLEMENTATION OF FREIGHT AND TRANSIT SIGNAL PRIORITIES TO ENHANCE ROAD TRAFFIC SUSTAINABILITY

Unknown Date (has links)
Lately, the attractiveness of cities has contributed to a rise in vehicle movements to and from cities. The growth of freight movements in cities predictably will be one of the critical issues of the near future. Congestion caused by the increased movements of freight impacts the flow of private and transit vehicles. Thus, it is crucial to reduce the congestion on multimodal corridors. Components of the Intelligent Transportation System (ITS) such as Freight Signal Priority (FSP) and Transit Signal Priority (TSP) that promote the freight and transit vehicles may not only help solve these conditions but may assist with the sustainability of the system. The primary objective of this research is to develop guidelines for traffic agencies to implement signal priorities based on identified decision factors on certain corridors. Besides, this study evaluates the efficiency of FSP and TSP in improving the performance of freight and transit systems. Finally, inclusive guidelines are drawn up based on the literature and the conducted simulation. The developed guidelines apply to corridors where freight delay plays a vital role in the assessment of corridor benefits. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection
96

Easy Parking

Galarreta Alemán, Mariafe, Perez Silva, Neri, Sato Noriega , Akemi, Torres Ramírez , Ingrid Fabiola, Torres Lázaro, Rommel Jair 15 July 2020 (has links)
En Lima, se ha incrementado la cantidad de autos y camionetas, pese a ello no hay una adecuada infraestructura lo que genera déficit de estacionamientos para la cantidad de personas que compran autos nuevos (Gestión, 2018). Un informe de INEI (2018) manifiesta que los espacios para estacionar son escasos para el incremento de autos de 20% desde el 2014 al 2018. Pese a ello, las playas de estacionamiento no se han visto incrementados en la misma proporción debido a la menor cantidad de terrenos libres para operar. En consecuencia, no se ha podido cubrir la demanda de parqueos en la actualidad (Municipalidad de Lima, 2017). Por ello, se creó a Easy parking, un sistema de parqueo innovador en el centro histórico de Lima que consiste en dar solución a la escasez de estacionamientos, un sistema de parqueo rotativo y automático que utiliza el espacio vertical de los aires para aparcar y no el espacio horizontal. Con esta tecnología, Easy Parking podrá estacionar 10 autos en lugar de 2 como los estacionamientos tradicionales de la competencia, siendo una alternativa de solución al congestionamiento vehicular y a la falta de parqueos en el lugar. Asimismo, para hacer el negocio más eficiente e innovador, se creó una aplicación móvil para reservar los estacionamientos disponibles en línea. Luego de analizar el mercado y de diseñar las especificaciones técnicas del servicio se concluye que Easy Parking es un proyecto viable y rentable por sus indicadores que confirman su rentabilidad y viabilidad. / In Lima, the number of cars and trucks has increased, despite this, there is no adequate infrastructure, which generates a parking deficit for the number of people who buy new cars (Gestión, 2018). A report by INEI (2018) states that parking spaces are scarce for the 20% increase in cars from 2014 to 2018. Despite this, parking spaces have not been increased in the same proportion due to the lower amount of free land to operate. Consequently, it has not been possible to cover the parking demand at present (Municipality of Lima, 2017). For this reason, Easy parking was created, an innovative parking system in the historic center of Lima that consists of solving the shortage of parking lots, a rotary and automatic parking system that uses the vertical space of the air to park and not horizontal space. With this technology, Easy Parking will be able to park 10 cars instead of 2 like the traditional parking lots of the competition, being an alternative solution to vehicular congestion and the lack of parking on site. In addition, to make business more efficient and innovative, a mobile application was created to reserve parking spaces available online. After analyzing the market and designing the technical specifications of the service, it is concluded that Easy Parking is a viable and profitable project due to its indicators that confirm its profitability and viability. / Trabajo de investigación
97

Traffic Congestion Mitigation as an Emissions Reduction Strategy

Bigazzi, Alexander York 01 January 2011 (has links)
Policy-makers, transportation researchers, and activists often assume that traffic congestion mitigation results in reduced vehicle emissions without proper justification or quantification of the benefits. If congestion mitigation is going to be tied to air quality goals, a better understanding of the impacts of traffic congestion on motor vehicle emissions is needed. This research addresses that need by investigating under which circumstances the commonly held assumption linking congestion mitigation to emissions reductions is valid. We develop and apply a mathematical framework to study the trade-offs between vehicle efficiency and travel demand that accompany travel speed changes. While the exact relationships among emissions, travel speed, and travel demand vary with location and pollutant, several consistent results arise. The potential for marginal emissions rate reductions through average travel speed adjustments is small for speeds between about 25 and 70 mph. Emissions rate sensitivity to speed increases with the fraction of heavy-duty vehicles and for certain pollutants (gaseous hydrocarbons and particulate matter), and decreases with the fraction of advanced-drivetrain vehicles, such as electric and gas-electric hybrid vehicles. But travel volume is also a key consideration for the total emissions impacts of congestion and congestion mitigation. While travel speed increases are generally expected to increase efficiency, they are also expected to increase vehicle travel volume as a result of induced demand. To explore efficiency and volume trade-offs we look at emissions break-even conditions for average speed and travel demand elasticity. Depending on the pollutant and the vehicle fleet, total emissions are only expected to decrease with increasing travel speed for initial conditions of both low demand elasticity and low average speed. Thus, higher levels of congestion do not necessarily increase emissions, nor will congestion mitigation inevitably reduce emissions. This result includes projects that seek to increase vehicle throughput from existing roadway supply through better traffic management and operations. Congestion mitigation through reduced vehicle volumes, on the other hand, presents the opportunity for additive emissions benefits through efficiency improvements and total Vehicle Miles Traveled (VMT) reductions. Comparing capacity-based congestion mitigation strategies with alternative emissions reduction strategies we show that where emissions reductions are possible through speed increases, the emissions benefits are likely to be more easily and cost-effectively attained by other strategies. A sketch analysis of vehicle-class segregated facilities shows that truck-only lane strategies consistently out-perform general-purpose/mixed-flow lane strategies in terms of emissions reductions. An analysis of several congestion-related performance measures shows that for reflecting emissions impacts, VMT is an essential component of performance. Thus, alternative congestion metrics such as total/excess travel distance and travel time are preferable emissions performance indicators to speed or distance-normalized delay. The Travel Time Index, in particular, poorly reflects emissions changes on congested roadways. This thesis offers several original contributions to the body of knowledge regarding congestion and emissions. First, it describes a parsimonious conceptual framework for assessing the effect of congestion on emissions. Then from that framework, several simple and original equations are presented which can be used for sketch-level planning to estimate emissions impacts from congestion mitigation. Finally, application of the framework provides quantitative support for the decoupling of congestion and emissions mitigations.
98

Multi-Criteria Trucking Freeway Performance Measures for Congested Corridors

Wheeler, Nicole Marie 01 January 2010 (has links)
This research focuses on the development of multi-criteria tools for measuring and analyzing the impacts of recurring and non-recurring congestion on freight corridors in the Portland Metropolitan Area. Unlike previous studies, this work employs several distinct data sources to analyze the impacts of congestion on Interstate 5 (I-5) in the Portland Metropolitan Area: global positioning system (GPS) data from commercial trucks and Oregon DOT corridor travel-time loop data and incident data. A new methodology and algorithms are developed to combine these data sources and to estimate the impacts of recurrent and non-recurrent congestion on freight movements' reliability and delays, costs, and emissions. The results suggest that traditional traffic sensor data tend to underestimate the impacts of congestion on commercial vehicles travel times and variability. This research also shows that congestion is not only detrimental for carriers and shippers costs but also for the planet due to major increases in GHG emissions and for the local community due to large increases in NOx, PM, and other harmful pollutants. The methodology developed throughout this work has the potential to provide useful freight operation and performance data for transportation decision makers to incorporate freight performance measures into the planning process.
99

A Geometric Design of Traffic-Light Roads Crossing Using the Continuous Flow Intersections Methodology to Reduce Points of Primary Conflicts Caused by Left Turns

Chuco, Betsi, Pérez, Carlos, Silvera, Manuel, Campos, Fernando 01 January 2021 (has links)
El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / The continuous flow intersections (CFI) increase the operational capacity of road systems with congestion problems, by using shared lanes located at the access points before the intersection. However, the CFI presents road safety risks that increase the likelihood of vehicle collision. This article proposes a geometric design composed of raised delineators at a traffic-light intersection, whose objective is to eliminate the points of primary conflicts caused by the left turns of the vehicles. To do this, a study was conducted to identify the different maneuvers present in a wide cross-type intersection in a commercial area located in the city of Lima. A total of 3219 vehicles was collected, of which 561 vehicles turned left demonstrating the high density of this type of maneuver. The effectiveness of the proposed design is validated using a microsimulation in the Vissim program. The results show that it was reduced from 58 to 8 points of conflict, increasing operational capacity by 34.97%. Finally, the risks caused by CFI decreased by 83%. / Revisión por pares
100

Adopting Transit-Oriented Development (TOD)in Metro-Manila Railway system : Considering Sweden’s Experience and Learning

Arian Far, Farhad January 2019 (has links)
Transit-oriented development (TOD) or as it is referred to in Sweden ABC (Arbete, Bostad,och Centrum which means work, housing, and city center) is the highly prevailing and excitingconcept of integrating urban communities, activities, people, buildings and public places together.This idea is primarily focused upon the creation of walkable, pedestrian-oriented communities andcycling connections, which are centered among the high-quality train systems.This research has been conducted to provide a comprehensive analysis related to theimplementation of the TOD model within Metro-Manila, by enhancing its railway network toreduce the problem of high traffic congestion and to provide a better service to a larger number ofpassengers. To carry out this research, various ideas were taken from the TOD projects that havebeen implemented within the metro system of Stockholm as an example to be used for Metro-Manila.In order to conduct this study, both quantitative and qualitative research approaches wereutilized to conduct an in-depth analysis of the current conditions of the railway transportationsystem in Metro-Manila. Within the qualitative part of this research, a SWOT analysis and adetailed comparison was also carried out to determine the efficiency of Metro-Manila and the areaswhere it needed significant improvements. Whereas, for the quantitative analysis, a survey wasconducted from both the people of Metro-Manila and Stockholm (i.e., 226 respondents) tounderstand the current situations of these railway networks more appropriately. The survey wasdesigned based on close-ended five (5) points Likert Scale questions. The results of the surveysrevealed that the respondents were mostly satisfied with the metro system in Stockholm andimplementation of the TOD concepts but usually dissatisfied with Metro-Manila railway system.An interview was also conducted with the officials of the Stockholm transport organization (SL)to gather more insight related to the problems within the railway networks.It was revealed from the analysis that Metro-Manila railway network has been facingsevere problems in terms of limited capacity, poor facilities, unavailability of trains, andmismanagement. The analysis also revealed a few problems within the Stockholm metro systemas well. However, to eradicate or mitigate these problems, several strategies and recommendationshave been proposed within this research. Based from the facts the researcher has gathered and ispresented in this research paper, it was evident that implementation of transit-orienteddevelopment, even if its limited to just the basic concepts, will highly be beneficial in botheconomic and societal aspects and its effectively and efficiently is enough to satisfy the needs ofthe daily commuters and would result in a dramatical reduction of traffic congestions.

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