Rozprawy doktorskie: „Traffic congestion”

1

Bojs, Eric. "Quantifying Traffic Congestion in Nairobi". Thesis, KTH, Matematisk statistik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-275684.

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This thesis aims to give insight into a novel approach for quantifying car traffic in developing cities. This is necessary to improve efficiency in resource allocation for improvements in infrastructure. The project took form of a case study of neighborhoods in the city of Nairobi, Kenya. The approach consists of a method which relies on topics from the field of Topological Data Analysis, together with the use of large data sources from taxi services in the city. With this, both qualitative and quantitative insight can be given about the traffic. The method was proven useful for understanding how traffic spreads, and to differentiate between levels of congestion: quantifying it. However, it failed to detect the effect of previous improvements of infrastructure.
Målet med rapporten är att ge insikt i en innovativ ansats för att kvantifiera biltrafik i utvecklingsstäder. Detta kommer som en nödvändighet för att kunna förbättra resursfördelning i utvecklandet av infrastruktur. Projektet utspelade sig som en fallstudie där stadsdelar i Nairobi, Kenya studerades. Ansatsen innefattar en metod som bygger på tekniker från topologisk dataanalys (eng. \textit{Topological Data Analysis}), tillsammans med stora datakällor från taxitjänster i staden. Detta hoppas ge både kvalitativ och kvantitativ information om trafiken i staden. Metoden visade sig vara användbar för att förstå hur trafik sprider sig och att differentiera mellan nivåer av trafik, alltså att kvantifiera den. Tyvärr så misslyckades metoden visa sig användbar för att mäta förbättringar i infrastruktur.

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Lerz, Stefan. "Congestion theory and railway traffic /". Capelle a/d IJssel : Labyrint, 1996. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=007375963&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.

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Wong, Wan-ho. "Bus to bus interchange : solution for traffic congestion in Hong Kong Island /". Hong Kong : University of Hong Kong, 2001. http://sunzi.lib.hku.hk:8888/cgi-bin/hkuto%5Ftoc%5Fpdf?B23425787.

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Ramakrishna, Sajja D. "An approach to predict traffic congestion". Thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-09192009-040304/.

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Welzl, Michael. "Network congestion control : managing Internet traffic /". Chichester [u.a.] : Wiley, 2005. http://www.loc.gov/catdir/toc/ecip0513/2005015429.html.

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6

Lee, Tak-kwong. "A study of the traffic congestion problem in Hong Kong : a case study of Wanchai district /". Hong Kong : University of Hong Kong, 1998. http://sunzi.lib.hku.hk/hkuto/record.jsp?B19906511.

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7

Huisken, Giovanni. "Inter-urban short-term traffic congestion prediction". Enschede : University of Twente [Host], 2006. http://doc.utwente.nl/57639.

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8

Drum, David K. "Counteracting traffic congestion using intelligent driver feedback". Thesis, University of Missouri - Columbia, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10180875.

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Traffic congestion is a daily occurrence in urban highway networks worldwide. It is not possible, however, for society to build its way out of congestion; rather, smarter roads and vehicles are needed. While the development of a smarter transportation system is underway, full implementation is years or decades from now. Yet, some of the sensing technology needed for smarter vehicles is already widely deployed in the form of smart phones. This thesis develops a novel method for recognizing traffic congestion using an artificially intelligent heuristic that could be implemented in a smart phone application or embedded system. Its goal is to provide intelligent feedback to a driver or autonomous vehicle control system to counteract stop-and-go traffic, a defining feature of urban highway congestion. Evaluation of the method indicates that a specific condition during stop-and-go traffic can be recognized accurately. A driver or control system acting upon feedback provided by the artificially intelligent system can improve traffic flow on the roadway by 1% to 3.5% over the course of the test duration.

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Arya, Vijay. "Congestion inference and traffic engineering in networks". Nice, 2005. http://www.theses.fr/2005NICE4079.

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Cette thèse présente des mécanismes pour obtenir de meilleures estimations de la congestion sur Internet. Elle présente également un mécanisme ayant des applications sur le trafic multipoint dans des réseaux overlay. Tout d’abord, nous présentons une méthode de différenciation des pertes qui permet aux protocoles de transport non fiables d’estimer avec précision la congestion de bout-en-bout, en distinguant les pertes liées à la congestion des pertes liées aux erreurs de transmission sur les liaisons sans fil. Ensuite, nous présentons deux contributions relatives à un outil de tomographie de réseau. Nous proposons d’une part un algorithme statistique qui vérifie les mesures binaires effectuées en multipoint par MINC pour estimer les pertes. Cet algorithme permet de garantir une estimation fiable des taux de pertes sur les différents liens. D’autre part, nous proposons une nouvelle version de l’estimateur de perte MINC. Notre estimateur utilise les informations multipoints cumulées fournies en retour pour évaluer les taux de perte sur tous les liens. Il peut être utilisé dans des situations où la bande passante pour transmettre les rapports de réception est faible. Enfin, nous présentons des techniques efficaces pour encoder les arbres de transmission multipoint au sein des paquets de données. Ces techniques d’encodage peuvent être utilisées pour implanter un routage multipoint explicite et sans état dans des réseaux overlay et ont donc des applications dan le domaine d’ingénierie de trafic multipoint
This thesis presents methods which help to improve the quality of congestion inference on both en-to-end paths and internal network links in the Internet and a method which help to perform multicast traffic engineering in Overlay Networks. First, we propose an explicit loss differentiation scheme which allows unreliable transport protocols to accurately infer congestion on end-to-end paths by correctly differentiating congestion losses from wireless losses. Second, we present two contributions related to Multicast-based Inference of Network Characteristics (MINC). MINC is a method of performing network tomography which infers loss rates, i. E. , congestion on internal network links from end-to-end multicast measurements. We propose a statistical verification algorithm which can verify the integrity of binary multicast measurements used by MINC to perform loss inference. This algorithm helps to ensure a trustworthy inference of link loss rates. Next, we propose an extended MINC loss estimator which can infer loss rates of network links using aggregate multicast feedbacks. This estimator can be used to perform loss inference in situations where the bandwidth to report multicast feedbacks is low. Third, we present efficient ways of encoding multicast trees within data packets. These encodings can be used to perform stateless and explicit multicast routing in overlay networks and thus achieve goals of multicast traffic engineering

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10

Raman, Mala. "Supply management measures for alleviating urban traffic congestion". Master's thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-03302010-020519/.

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Wan, Kam Hung. "Transit services planning with congestion /". View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202006%20WAN.

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Cherrett, Thomas James. "Congestion and driver response". Thesis, University of Southampton, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244976.

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Kam, Yee-sheung Karen. "A study of the Hong Kong government's transport policy : the formulation of a comprehensive, multi-pronged approach to solving traffic congestion in Hong Kong /". Hong Kong : University of Hong Kong, 1996. http://sunzi.lib.hku.hk/hkuto/record.jsp?B17507546.

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14

Kuchi, Mahathi B. "Assessing the relationship between recurring and nonrecurring traffic congestion". Thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-06102009-063124/.

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15

Acha-Daza, Jorge. "The user's response to pricing in a traffic network /". Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.

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Bruce, Edward L. "An enhanced methodology for quantifying Urban freeway congestion and its uses within the congestion management system". Thesis, Georgia Institute of Technology, 1994. http://hdl.handle.net/1853/21259.

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Lee, Yan-pui, i 李昕鋇. "A new approach to presenting congestion level alerts to road users". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B46541421.

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Cheevarunothai, Patikhom. "Development of methods for improving inductance loop data quality and quantifying incident-induced delay on freeways /". Thesis, Connect to this title online; UW restricted, 2008. http://hdl.handle.net/1773/10204.

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Biswas, Md Israfil. "Internet congestion control for variable-rate TCP traffic". Thesis, University of Aberdeen, 2011. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=182264.

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The Transmission Control Protocol (TCP) has been designed for reliable data transport over the Internet. The performance of TCP is strongly influenced by its congestion control algorithms that limit the amount of traffic a sender can transmit based on end-to-end available capacity estimations. These algorithms proved successful in environments where applications rate requirements can be easily anticipated, as is the case for traditional bulk data transfer or interactive applications. However, an important new class of Internet applications has emerged that exhibit significant variations of transmission rate over time. Variable-rate traffic poses a new challenge for congestion control, especially for applications that need to share the limited capacity of a bottleneck over a long delay Internet path (e.g., paths that include satellite links). This thesis first analyses TCP performance of bursty applications that do not send data continuously, but generate data in bursts separated by periods in which little or no data is sent. Simulation analysis shows that standard TCP methods do not provide efficient support for bursty applications that produce variable-rate traffic, especially over long delay paths. Although alternative forms of congestion control like TCP-Friendly Rate Control and the Datagram Congestion Control Protocol have been proposed, they did not achieve widespread deployment. Therefore many current applications that rely upon User Datagram Protocol are not congestion controlled. The use of non-standard or proprietary methods decreases the effectiveness of Internet congestion control and poses a threat to the Internet stability. Solutions are therefore needed to allow bursty applications to use TCP. Chapter three evaluates Congestion Window Validation (CWV), an IETF experimental specification that was proposed to improve support for bursty applications over TCP. It concluded that CWV is too conservative to support many bursty applications and does not provide an incentive to encourage use by application designers. Instead, application designers often avoid generating variable-rate traffic by padding idle periods, which has been shown to waste network resources. CWV is therefore shown to not provide an acceptable solution for variable-rate traffic. In response to this shortfall, a new modification to TCP, TCP-JAGO, is proposed. This allows variable-rate traffic to restart quickly after an inactive (i.e., idle) period and to effectively utilise available network resources while sending at a lower rate than the available rate (i.e., during an application-limited period). The analysis in Chapter five shows that JAGO provides faster convergence to a steady-state rate and improves throughput by more efficiently utilising the network. TCP-JAGO is also shown to provide an appropriate response when congestion is experienced after restart. Variable-rate TCP traffic can also be impacted by the Initial Window algorithm at the start or during the restart of a session. Chapter six considers this problem, where TCP has no prior indication of the network state. A recent proposal for a larger initial window is analysed. Issues and advantages of using a large IW over a range of scenarios are discussed. The thesis concludes by presenting recommendations to improve TCP support for bursty applications. This also provides an incentive for application designers to choose TCP for variable-rate traffic.

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Kelley, Simon Richard. "Congestion control for unreserved traffic in ATM networks". Thesis, University of Cambridge, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.319763.

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21

Bigazzi, Alexander York. "Traffic Congestion Mitigation as an Emissions Reduction Strategy". PDXScholar, 2011. https://pdxscholar.library.pdx.edu/open_access_etds/131.

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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.

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Yang, Yang. "Network congestion control". Access restricted to users with UT Austin EID, 2001. http://wwwlib.umi.com/cr/utexas/fullcit?p3037028.

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Raheja, Tushar. "Modelling traffic congestion - to wait or to be late". Thesis, IIT Delhi, 2016. http://localhost:8080/iit/handle/2074/7009.

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Surabhi, Suman Reddy. "Traffic responsive signal systems to address rain-related congestion". Birmingham, Ala. : University of Alabama at Birmingham, 2008. https://www.mhsl.uab.edu/dt/2008m/surabhi.pdf.

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Bui, Kim Thien. "Dynamic traffic congestion pricing mechanism with user-centric considerations". Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/85817.

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Thesis: S.M. in Transportation, Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2013.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 85-95).
In this thesis, we consider the problem of designing real-time traffic routing systems in urban areas. Optimal dynamic routing for multiple passengers is known to be computationally hard due to its combinatorial nature. To overcome this difficulty, we propose a novel mechanism called User-Centric Dynamic Pricing (UCDP) based on recent advances in algorithmic mechanism design. The mechanism allows for congestion-free traffic in general road networks with heterogeneous users, while satisfying each user's travel preference. The mechanism first informs whether a passenger should use public transportation or the road network. In the latter case, a passenger reports his maximum accepted travel time with a lower bound announced publicly by the road authority. The mechanism then assigns the passenger a path that matches with his preference given the current traffic condition in the network. The proposed mechanism introduces a fairness constrained shortest path (FCSP) problem with a special structure, thus enabling polynomial time computation of path allocation that maximizes the sequential social surplus and guarantees fairness among passengers. The tolls of paths are then computed according to marginal cost payments. We show that reporting true preference is a weakly dominant strategy. The performance of the proposed mechanism is demonstrated on several simulated routing experiments in comparison to user equilibrium and system optimum.
by Kim Thien Bui.
S.M. in Transportation

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Soelistijanto, Bambang. "Traffic distribution fairness and congestion in social opportunistic networks". Thesis, University of Surrey, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.616477.

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Social opportunistic networks (SONs) are intermittently-connected networks that exploit unpredictable contacts between users' mobile devices. The connectivity of SONs exhibits a nonrandom structure with the existence of a few hub nodes and social-aware routing protocols favour these nodes as the best carriers for message transfers. As a result, the network suffers from unbalanced traffic distribution leading to traffic congestion in the hub nodes. In this thesis, strategies for improving traffic distribution fairness in SONs and reducing traffic congestion in hub nodes are considered. The thesis proposes three innovative contributions as follows. An Analysis of traffic distribution and network capacity in SONs is fIrst performed. It considers the traffic distribution in a SON, and characterizes the network as being scale-free. Several forwarding strategies are considered, based on the routing information required by a node, i.e. isolated, local and complete networks. A network capacity model for a SON is then derived as an upper-bound of network delivery performance, where hub nodes' resources become the limiting factor. The analytical study shows that unfair traffic distribution occurs in the network for all three forwarding strategies, because a few hub nodes process a large fraction of the traffic. A Traffic Distribution Aware (TraDA) routing protocol is therefore proposed, aimed at improving traffic distribution fairness in SONs. A novel computation of node global popularity (the TraDA routing metric) is proposed, comprising node intrinsic popularity and social-relations popularity calculations. TraDa-Comm, a community-aware variant of TraDA, is also presented and simulation results show that it achieves better traffic distribution fairness than the state-of-the-art Bubble Rap, without degrading network delivery performance.

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Huang, Changcheng Carleton University Dissertation Engineering Systems and Computer. "Long range dependent traffic: modeling, simulation and congestion control". Ottawa, 1996.

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Rivera, Saavedra Gabriel, i Ochochoque Luis Alberto Velásquez. "Propuesta de implementación de un sistema de semaforización inteligente para mejorar los niveles de servicio de la Av. Javier Prado Oeste, tramo Ca. Las Palmeras y Ca. Las Flores en el distrito de San Isidro". Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2020. http://hdl.handle.net/10757/651707.

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La presente investigación analiza las condiciones de tráfico vehicular actual en dos intersecciones de la avenida Javier Prado Oeste, tramo Calle Las Flores & Calle Las Palmeras, en el distrito de San Isidro. La investigación empieza con la descripción de los problemas existentes en las intersecciones, como la deficiente programación de semáforos, falta de semáforos coordinados e incompatibilidad entre controladores semafóricos. El análisis de la investigación se realizó en base a un modelo microscópico, desarrollado con apoyo del software Vissim. El proceso de construcción de ambos modelos consiste en cuatro fases. La primera fase es el trabajo previo, en la cual se realizó la recolección de datos de campo. En segundo lugar, se encuentra la construcción de los modelos mediante el programa. En tercer lugar, se realizó la calibración y validación de ambos modelos en base a parámetros psicofísicos y estadísticos GEH para certificar que los resultados del modelo se asemejen a las condiciones actuales de las intersecciones. Por último, se incorporaron los nuevos flujos futuros en los modelos cada 15 minutos los cuales se simularon, evaluaron y compararon con los niveles de servicio obtenidos con las intersecciones proyectadas que incorporan la propuesta de mejora. Esencialmente los niveles de servicio de las intersecciones mejoran incorporando la propuesta de semáforos inteligente por medio de la optimización de ciclos semafóricos con el programa Synchro 10.0, esto se deduce a partir de la disminución de longitudes de colas en todos los accesos y la reducción de demoras de viaje en ambas intersecciones.
The present investigation analyzes the current vehicular traffic conditions at two intersections of Javier Prado Oeste Avenue, Las Flores Street and Las Palmeras Street, in the San Isidro district. The investigation begins with the description of the problems existing at the intersections, such as poor traffic light programming, lack of coordinated traffic lights and incompatibility between traffic light controllers. The research analysis was carried out based on a microscopic model, developed with the support of Vissim software. The construction process of both models consists of four phases. The first phase is the previous work, in which the field data collection was carried out. Second, there is the construction of the models through the program. Third, the calibration and validation of both models was performed based on GEH psychophysical and statistical parameters to certify that the results of the model resemble the current conditions of the intersections. Finally, the new future flows were incorporated into the models every 15 minutes, which were simulated, evaluated and compared with the service levels obtained with the projected intersections that incorporate the improvement proposal. Essentially, the service levels of the intersections improve by incorporating the smart traffic lights proposal through the optimization of traffic light cycles with the Synchro 10.0 program, this is deduced from the decrease in queue lengths in all accesses and the reduction of delays of travel at both intersections.
Tesis

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Suthiranart, Yaourai. "The transportation crisis in Bangkok : an exploratory evaluation /". Thesis, Connect to this title online; UW restricted, 2001. http://hdl.handle.net/1773/10827.

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Ng, Ka-wing Simon. "Cross border freight traffic congestion : the Hong Kong-Shenzhen case /". [Hong Kong] : University of Hong Kong, 1994. http://sunzi.lib.hku.hk/hkuto/record.jsp?B13730897.

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Sivanandan, R. "A linear programming approach for synthesizing origin-destination (O-D) trip tables from link traffic volumes". Diss., This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-07102007-142518/.

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Mohamed, Samatha Ann. "The feasibility of a congestion charge for Cape Town central business district from a traffic engineering perspective /". [S.l. : s.n.], 2008. http://dk.cput.ac.za/cgi/viewcontent.cgi?article=1068&context=td_cput.

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Lai, Chengdi, i 賴成迪. "Systematic design of internet congestion control : theory and algorithms". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/206356.

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The Internet is dynamically shared by numerous flows of data traffic. Network congestion occurs when the aggregate flow rate persistently exceeds the network capacity, leading to excessive delivery delay and loss of user data. To control network congestion, a flow needs to adapt the sending rate to its inferred level of congestion, and a packet switch needs to report its local level of congestion. In this framework of Internet congestion control, it is important for flows to react promptly against congestion, and robustly against interfering network events resembling congestion. This is challenging due to the highly dynamic interactions of various network components over a global scale. Prior approaches rely predominantly on empirical observations in experiments for constructing and validating designs. However, without a careful, systematic examination of all viable options, more efficient designs may be overlooked. Moreover, experimental results have limited applicability to scenarios beyond the specific experimental settings. In this thesis, I employ a novel, systematic design approach. I formalize the design process of Internet congestion control from a minimal set of empirical observations. I prove the robustness and optimality of the attained design in general settings, and validate these properties in practical experimental settings. First, I develop a systematic method for enhancing the robustness of flows against interfering events resembling congestion. The class of additive-increase-multiplicative-decrease (AIMD) algorithms in Transmission Control Protocol (TCP) is the set of dominant algorithms governing the flow rate adaptation process. Over the present Internet, packet reordering and non-congestive loss occur frequently and are misinterpreted by TCP AIMD as packet loss due to congestion. This leads to underutilization of network resources. With a complete, formal characterization of the design space of TCP AIMD, I formulate designing wireless TCP AIMD as an optimal control problem over this space. The derived optimal algorithm attains a significant performance improvement over existing enhancements in packet-level simulation. Second, I propose a novel design principle, known as pricing-link-by-time (PLT), that specifies how to set the measure of congestion, or “link price”, at a router to provide prompt feedback to flows. Existing feedback mechanisms require sophisticated parameter tuning, and experience drastic performance degradation with improperly tuned parameters. PLT makes parameter tuning a simple, optional process. It increases the link price as the backlog stays above a threshold value, and resets the price once the backlog goes below the threshold. I prove that such a system exhibits cyclic behavior that is robust against changes in network environment and protocol parameters. Moreover, changing the threshold value can control delay without undermining system performance. I validate these analytical results using packet-level simulation. The incremental deployment of various enhancements have made Internet congestion control highly heterogeneous. The final part of the thesis studies this issue by analyzing the competition among flows with heterogeneous robustness against interfering network events. While rigorous theories have been a major vehicle for understanding system designs, the thesis involves them directly in the design process. This systematic design approach can fully exploit the structural characteristics, and lead to generally applicable, effective solutions.
published_or_final_version
Electrical and Electronic Engineering
Doctoral
Doctor of Philosophy

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Nam, Doohee. "Econometric analysis of highway incident duration, public perceptions and information for advanced traveler information systems /". Thesis, Connect to this title online; UW restricted, 1997. http://hdl.handle.net/1773/10172.

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Lindberg, Per Olov. "Aspects of Static Multi-Class Traffic equilibria under Congestion Pricing". Licentiate thesis, KTH, Transport and Location Analysis, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-12963.

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Congestion charging is a now accepted means of influencing traffic to behave in a more socio-economic optimal way, like e.g. in the Stockholm project. Already early work, in the 1920’s, showed that road use can be inefficient due externalities, i.e. that users don’t experience their own (negative) effect on other users: an extra car on a traffic link causes delays for other cars, but the driver himself does not experience this cost.In the 1950’s it was further shown - for a congested road network with homogeneous users – that if each user is charged a toll equal to the total value of time loss incurred on other users of the network, then -if we have fixed travel demand - this will induce an equilibrium that is system optimal in the sense that the total cost of network usage is minimal (assuming that all users have fixed and identical time values). But toll charges need to be levied in monetary units, and different travelers have different values of time. Therefore, to account for the effects of tolls, and to be able to compute equilibria, one needs to introduce different user classes, differing in their time values.

In this thesis, consisting of four papers, we study congestion pricing of road networks with users differing only in their time values. In particular, we analyze marginal social cost (MSC) pricing, a tolling scheme that charges each user a penalty corresponding to the value of the delays inflicted on other users, as well as its implementation through fixed tolls.

Paper III contains the main theoretical work of the thesis. In that paper we show that the variational inequalities characterizing the equilibria in question can be stated in symmetric or non-symmetric forms. The symmetric forms correspond to optimization problems, convex in the fixed-toll case and non-convex in the MSC case, which hence may have multiple equilibria. The objective of the latter problem is the total value of travel time, which thus is minimized at the global optima of that problem. Implementing close-to-optimal MSC tolls as fixed tolls leads to equilibria with possibly non-unique class specific flows, but with identical close-to-optimal values of the total value of travel time. Finally we give an adaptation, to the MSC setting, of the Frank-Wolfe algorithm, which is further applied to some test cases, including Stockholm.

Paper I is an early application using Frank-Wolfe, after having realized the possibility to symmetrize the problem.

Paper II gives a convexification of non-convex equilibrium problem for MSC tolls. We have used these convexifications to compute lower bounds when computing equilibria.

Paper IV is a short note commenting some flaws in two papers by Dial on MSC tolls.

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Ng, Ka-wing Simon, i 吳家穎. "Cross border freight traffic congestion: the Hong Kong-Shenzhen case". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1994. http://hub.hku.hk/bib/B3121180X.

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Lim, Sejoon. "Congestion-aware traffic routing for large-scale mobile agent systems". Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/78452.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 191-201).
Traffic congestion is a serious world-wide problem. Drivers have little knowledge of historical and real-time traffic congestion for the paths they take and often tend to drive suboptimal routes. Congestion phenomena are sure to be influenced by the coming of autonomous cars. This thesis presents route planning algorithms and a system for either autonomous or human-driven cars in road networks dealing with travel time uncertainty and congestion. First, a stochastic route planning algorithm is presented that finds the best path for a group of multiple agents. Our algorithm provides mobile agents with optimized routes to achieve time-critical goals. Optimal selections of agent and visit locations are determined to guarantee the highest probability of task achievement while dealing with uncertainty of travel time. Furthermore, we present an efficient approximation algorithm for stochastic route planning based on pre-computed data for stochastic networks. Second, we develop a distributed congestion-aware multi-agent path planning algorithm that achieves the social optimum, minimizing aggregate travel time of all the agents in the system. As the number of agents grows, congestion created by agents' path choices should be considered. Using a data-driven congestion model that describes the travel time as a function of the number of agents on a road segment, we develop a practical method for determining the optimal paths for all the agents in the system to achieve the social optimum. Our algorithm uses localized information and computes the paths in a distributed manner. We implement the algorithm in multi-core computers and demonstrate that the algorithm has a good scalability. Third, a path planning system using traffic sensor data is then implemented. We predict the traffic speed and flow for each location from a large set of sensor data collected from roving taxis and inductive loop detectors. Our system uses a data-driven traffic model that captures important traffic patterns and conditions using the two sources of data. We evaluate the system using a rich set of GPS traces from 16,000 taxis in Singapore and show that the city-scale congestion can be mitigated by planning drivers' routes, while incorporating the congestion effects generated by their route choices.
by Sejoon Lim.
Ph.D.

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Piironen, S. Annukka. "Multimedia traffic management and congestion control in satellite ATM networks". Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/36460.

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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1994.
Includes bibliographical references (leaves 101-102).
by S. Annukka Piironen.
M.S.

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Bakare, Bukola. "Corporate Social Responsibility and Traffic Congestion: A Mixed Methods Study". Diss., North Dakota State University, 2020. https://hdl.handle.net/10365/31782.

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Traffic congestion (TC) is a complex issue having an adverse impact on the environment, business operations and health. Many cities are taking action to curb it. Corporations have increasingly engaged in corporate social responsibility (CSR) actions. Using corporations headquartered in the top-rated traffic congested cities in the United States, this study examines the relationship between TC and CSR. The quantitative research employed a general linear model with two datasets, traffic speed data and CSRHub ratings. The speed data was used to calculate travel time index (TTI), a measure of TC. Using Atlanta BeltLine Inc. as a case study, a phenomenological thematic approach was utilized to assess stakeholders’ viewpoints of congestion mitigation efforts in Atlanta, GA. This study adds to research on CSR by examining the effects that CSR actions have on a specific local event, e.g., TC. In addition, research reflecting on the impact of CSR on TC has not been conducted. This study aims to fill this gap. Of the four areas of CSR studied in the quantitative phase, the community, environment, and governance ratings are significantly related to TTI, with community and environment having an inverse relationship to TTI. The qualitative study showed that stakeholders struggle with TC, and that the relationship between CSR and TC is not obvious to them. This quantitative study was conducted on eighteen top-rated congested cities. Further study on other major congested cities may shed more light on CSR and TC. A future qualitative analysis can explore the viewpoint of city government. Findings in this study are expected to be a leverage point for public-private TC mitigation and to inform policies that incorporate TC reduction as a CSR indicator. Although the quantitative analysis showed that a relationship exists between CSR and TC, the literature and DOT reports revealed increased and continuous congestion in these cities. The case study of the ABI project in the qualitative research indicated that TC is an area where CSR can have a major local impact. Some corporate respondents acknowledged that TC has a business cost, however no serious steps are taken to tackle TC.

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Thorri, Sigurdsson Thorsteinn. "Road traffic congestion detection and tracking with Spark Streaming analytics". Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-254874.

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Road traffic congestion causes several problems. For instance, slow moving traffic in congested regions poses a safety hazard to vehicles approaching the congested region and increased commuting times lead to higher transportation costs and increased pollution.The work carried out in this thesis aims to detect and track road traffic congestion in real time. Real-time road congestion detection is important to allow for mechanisms to e.g. improve traffic safety by sending advanced warnings to drivers approaching a congested region and to mitigate congestion by controlling adaptive speed limits. In addition, the tracking of the evolution of congestion in time and space can be a valuable input to the development of the road network. Traffic sensors in Stockholm’s road network are represented as a directed weighted graph and the congestion detection problem is formulated as a streaming graph processing problem. The connected components algorithm and existing graph processing algorithms originally used for community detection in social network graphs are adapted for the task of road congestion detection. The results indicate that a congestion detection method based on the streaming connected components algorithm and the incremental Dengraph community detection algorithm can detect congestion with accuracy at best up to 94% for connected components and up to 88% for Dengraph. A method based on hierarchical clustering is able to detect congestion while missing details such as shockwaves, and the Louvain modularity algorithm for community detection fails to detect congested regions in the traffic sensor graph.Finally, the performance of the implemented streaming algorithms is evaluated with respect to the real-time requirements of the system, their throughput and memory footprint.
Vägtrafikstockningar orsakar flera problem. Till exempel utgör långsam trafik i överbelastade områden en säkerhetsrisk för fordon som närmar sig den överbelastade regionen och ökade pendeltider leder till ökade transportkostnader och ökad förorening.Arbetet i denna avhandling syftar till att upptäcka och spåra trafikstockningar i realtid. Detektering av vägtrafiken i realtid är viktigt för att möjliggöra mekanismer för att t.ex. förbättra trafiksäkerheten genom att skicka avancerade varningar till förare som närmar sig en överbelastad region och för att mildra trängsel genom att kontrollera adaptiva hastighetsgränser. Dessutom kan spårningen av trängselutveckling i tid och rum vara en värdefull inverkan på utvecklingen av vägnätet. Trafikavkännare i Stockholms vägnät representeras som en riktad vägd graf och problemet med överbelastningsdetektering är formulerat som ett problem med behandling av flödesgrafer. Den anslutna komponentalgoritmen och befintliga grafbehandlingsalgoritmer som ursprungligen användes för communitydetektering i sociala nätgravar är anpassade för uppgiften att detektera vägtäthet. Resultaten indikerar att en överbelastningsdetekteringsmetod baserad på den strömmande anslutna komponentalgoritmen och den inkrementella Dengraph communitydetekteringsalgoritmen kan upptäcka överbelastning med noggrannhet i bästa fall upp till 94% för anslutna komponenter och upp till 88% för Dengraph. En metod baserad på hierarkisk klustring kan detektera överbelastning men saknar detaljer som shockwaves, och Louvain modularitetsalgoritmen för communitydetektering misslyckas med att detektera överbelastade områden i trafiksensorns graf.Slutligen utvärderas prestandan hos de implementerade strömmalgoritmerna med hänsyn till systemets realtidskrav, deras genomströmning och minnesfotavtryck.

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Chin, Kian Keong. "Departure time choice in equilibrium traffic assignment". Thesis, University of Leeds, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.364638.

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42

Sanhaji, Ali. "Nouveaux paradigmes de contrôle de congestion dans un réseau d'opérateur". Phd thesis, Toulouse, INPT, 2016. http://oatao.univ-toulouse.fr/17304/1/sanhaji.pdf.

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La congestion dans les réseaux est un phénomène qui peut influer sur la qualité de service ressentie par les utilisateurs. L’augmentation continue du trafic sur l’internet rend le phénomène de congestion un problème auquel l’opérateur doit répondre pour satisfaire ses clients. Les solutions historiques à la congestion pour un opérateur, comme le surdimensionnement des liens de son infrastructure, ne sont plus aujourd’hui viables. Avec l’évolution de l’architecture des réseaux et l’arrivée de nouvelles applications sur l’internet, de nouveaux paradigmes de contrôle de congestion sont à envisager pour répondre aux attentes des utilisateurs du réseau de l’opérateur. Dans cette thèse, nous examinons les nouvelles approches proposées pour le contrôle de congestion dans le réseau d’un opérateur. Nous proposons une évaluation de ces approches à travers des simulations, ce qui nous permet d’estimer leur efficacité et leur potentiel à être déployés et opérationnels dans le contexte d’internet, ainsi que de se rendre compte des défis qu’il faut relever pour atteindre cet objectif. Nous proposons également des solutions de contrôle de congestion dans des environnements nouveaux tels que les architectures Software Defined Networking et le cloud déployé sur un ou plusieurs data centers, où la congestion est à surveiller pour maintenir la qualité des services cloud offerts aux clients. Pour appuyer nos propositions d’architectures de contrôle de congestion, nous présentons des plateformes expérimentales qui démontrent le fonctionnement et le potentiel de nos solutions.

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Paksarsawan, Sompong. "The development of queuing simulation procedures for traffic in Bangkok". Thesis, University of Leeds, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.364645.

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Ganguly, Bulbul. "Evaluation of media tie-in with Gateway Guide ITS deployment in St. Louis, Missouri /". free to MU campus, to others for purchase, 2004. http://wwwlib.umi.com/cr/mo/fullcit?p1426057.

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Kwok, Shi-chung Colin. "The role of electronic road pricing in tackling traffic congestion in Hong Kong". Hong Kong : University of Hong Kong, 1999. http://sunzi.lib.hku.hk/hkuto/record.jsp?B21128832.

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Silveira, Filho Fernando Jorge. "Unsupervised diagnosis of network traffic anomalies". Paris 6, 2010. http://www.theses.fr/2010PA066243.

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Les opérateurs réseau doivent souvent s'occuper d'événements qui compromettent leurs réseaux. Une approche pour trouver ces événements est de surveiller le trafic dans un ou plusieurs liens et chercher des écarts importants par rapport à un modèle statistique du comportement normal. Ce problème, connu sous le nom de diagnostic d'anomalies de trafic, comporte deux étapes: la détection d'anomalies, et l'analyse de leurs causes racines. Les méthodes de détection d'anomalies doivent définir d'abord un modèle du trafic normal. Un autre problème avec les détecteurs actuels est qu'ils ne donnent aucune information permettant à identifier les flots de trafic responsables d'une anomalie. L'analyse des causes racines est le processus de récupération de ce type d'information, en cherchant des événements sur la trace de trafic qui pourraient expliquer l'alarme. Dans cette thèse, nous développons un système de diagnostic d'anomalies (c'est-à-dire, la détection et l'analyse des causes racines) qui expose une vaste gamme d'anomalies et explique leurs causes automatiquement. Nous proposons ASTUTE, un détecteur d'anomalies qui utilise un modèle de trafic non-paramétrique, et donc est simple à calculer et à l'abri de la contamination des données. Deuxièmement, nous proposons URCA, une technique qui automatise l'analyse des causes racines. URCA identifie le trafic anormal et le classifie selon le type de cause racine. Nous faisons des nombreuses expériences afin d'évaluer la performance de ces techniques. Nos résultats montrent que ASTUTE et URCA peuvent diagnostiquer correctement une multitude d'anomalies.

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Li, Man-hon. "Evaluation of traffic congestion relieving options with using cost-benefit analysis : case study of Central-Wan Chai /". View the Table of Contents & Abstract, 2005. http://sunzi.lib.hku.hk/hkuto/record/B35080747.

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Rivera, Saavedra Gabriel, i Ochochoque Luis Alberto Velásquez. "Determinación de ciclos semafóricos optimizados con Synchro 10.0 aplicados y evaluados en intersecciones de gran congestión vehicular con el software PTV Vissim 9.0". Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2019. http://hdl.handle.net/10757/626118.

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Este artículo presenta la evaluación del tráfico vehicular en dos intersecciones semaforizadas ubicadas en la ciudad de Lima; una de las principales ciudades del mundo con gran congestión vehicular; mediante un modelo microscópico desarrollado con el software Vissim 9.0. La finalidad de esta investigación es proponer la implementación de un sistema de semaforización inteligente para mejorar los niveles de servicio y disminuir la congestión vehicular. El proceso de construcción del modelo consiste en cuatro etapas. Primero, es el trabajo previo, en la cual se realizó la recolección de datos de campo. Luego, se construyó el modelo mediante el software Vissim 9.0. Después, se realizó la calibración y validación del modelo en ambas intersecciones en base a parámetros psicofísicos para certificar que los resultados del modelo se asemejen a las condiciones reales de las intersecciones. Por último, se incorporaron los nuevos flujos futuros en el modelo cada 15 minutos los cuales se simularon y evaluaron con los NS obtenidos, que incorporan la propuesta de mejora. Esencialmente los niveles de servicio de las intersecciones mejoran, determinando cada 15 minutos durante la hora pico nuevos ciclos semaforizados optimizados con el programa Synchro 10.0 aplicados a Vissim 9.0, pasando de un NS E a D, esto se deduce a partir de la disminución de longitudes de colas en todos los accesos y la reducción de las demoras de viaje, las cuales fueron 14% en la Av. Javier Prado – Ca. Las Flores y 24% en la Av. Javier Prado – Ca. Las Palmeras.
This paper presents the evaluation of vehicular traffic on two signalized intersections located in the city of Lima; one of the world's major cities with high traffic congestion; by microscopic model developed with Vissim 9.0 software. The purpose of this research is to propose the implementation of an intelligent traffic signals to improve service levels and reduce traffic congestion. The process of building the model consists of four stages. First, it is the previous work, in which the field data collection was performed. The model was then constructed by Vissim 9.0 software. After, calibration and validation of the model was performed on both intersections based on psychophysical parameters to certify that the model results resemble the actual conditions of intersections. Finally, new future flows were incorporated into the model every 15 minutes which were simulated and evaluated with the NS obtained, incorporating the proposed improvement. Essentially service levels intersections improve, determining every 15 minutes during rush hour new signalized cycles optimized with Synchro 10.0 program applied to Vissim 9.0, from an NS E to D, It follows from decreasing lengths queues at all entrances and reducing travel delays, which were 14% at Av. Javier Prado -. Ca. Las Flores and 24% on Av. Javier Prado -. Ca. Las Palmeras.
Tesis

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Bai, Lihui. "Computational methods for toll pricing models". [Gainesville, Fla.] : University of Florida, 2004. http://purl.fcla.edu/fcla/etd/UFE0006341.

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Poon, Ming-ho. "A dynamic schedule-based model for congested transit networks /". Hong Kong : University of Hong Kong, 2001. http://sunzi.lib.hku.hk/hkuto/record.jsp?B24729784.

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