Adaptive ramp metering (ARM) is a widely popular intelligent transportation system (ITS) tool that boasts the ability to reduce congestion and streamline traffic flow during peak hour periods while maintaining a lower implementation cost than traditional methods such as freeway widening. This thesis explores the effectiveness of ARM implementation on an 18 mile segment of the Interstate 80 (I-80) corridor in the Bay Area residing in northern California. Smaller segments of this particular segment were analyzed to determine the effective length of ARM on efficiency at various lengths originating from a known bottleneck location. Efficiency values were also compared against a control segment of the Interstate 280 (I-280) in San Jose to provide a test site experiencing similar traffic congestion but without any ARM implementation. An Empirical Bayes analysis was conducted to provide the foundation of a safety evaluation of the ramp metering implementation and determine a counterfactual estimate of expected collisions had ARM implementation not occurred. It was found that the installation of the ramp meters did allow for some marginal increases in efficiency but may not be entirely associated with ARM implementation due to a variety of external factors as well as showing inconsistent behavior between analyzed segments. Regarding safety, the predictive model estimates 32.8 collisions to occur along a 0.5 mile segment within a three-year timeframe if ARM were not installed, which implies substantial improvements in safety conditions. However additional efficiency and safety data within the “after” period may be necessary to provide a more robust and conclusive evaluation as the ARM system is still relatively new.

A door-to-door trip may involve multiple traffic modes. For example, travelers may drive to a subway station and make a transfer to rail transit; alternatively, people may also start their trips by walking/cycling to a bus/subway station and then take transit in most of the trip. A successful eco-route planning thus should be able to cover multiple traffic modes and offer intermodal routing suggestions. Developing such a system requires to address extensive concerns. The dissertation is a building block of the multi-modal energy-efficient routing system which is being developed and tested in the simulation environment before real applications. Four submodules have been developed in the dissertation as partial fulfillment of the simulation-based system: energy consumption modeling, subway system development, on-road vehicles dynamic eco-routing, and information effect on route choice behavior. Other submodules such as pedestrian/bicycle modeling will be studied in the future. Towards the research goal, the dissertation first develops fuel consumption models for on-road vehicles. Given that gasoline light duty vehicles (LDVs) and electric vehicles were modeled in previous studies, the research effort mainly focuses on heavy duty vehicles (HDVs). Specifically, heavy duty diesel trucks (HDDTs) as well as diesel and hybrid-electric transit buses are modeled. The models are developed based on the Virginia Tech Comprehensive Power-based Fuel consumption Modeling (VT-CPFM) framework. The results demonstrate that the model estimates are highly consistent with field observations as well as the estimates of the Comprehensive Modal Emissions Model (CMEM) and MOtor Vehicle Emissions Simulator (MOVES). It is also found that the optimum fuel economy cruise speed ranges between 32 and 52 km/h for the tested trucks and between 39 and 47 km/h for the tested buses on grades varying from 0% to 8%, which is significantly lower than LDVs (60-80 km/h). The dissertation then models electric train dynamics and energy consumption in support of subway simulation system development and trip energy estimation. The dynamics model varies throttle and brake level with running speed rather than assuming constants as was done by previous studies, and the energy consumption model considers instantaneous energy regeneration. Both models can be easily calibrated using non-engine data and implemented in simulation systems and eco-transit applications. The results of the dynamics modeling demonstrate that the proposed model can adequately capture instantaneous acceleration/deceleration behavior and thus produce realistic train trajectories. The results of the energy consumption modeling demonstrate that the model produces the estimates consistent with the National Transit Database (NTD) results, and is applicable for project-level analysis given its ability in capturing the energy consumption differences associated with train, route and operational characteristics. The most suitable simulation testbed for system development is then identified. The dissertation investigates four state-of-the-art microsimulation models (INTEGRATION, VISSIM, AIMSUM, PARAMICS). Given that the car-following model within a micro-simulator controls longitudinal vehicle motion and thus determines the resulting vehicle trajectories, the research effort mainly focuses on the performance of the built-in car-following models from the energy and environmental perspective. The vehicle specific power (VSP) distributions resulting from each of the car-following models are compared to the field observations. The results demonstrate that the Rakha-Pasumarthy-Adjerid (RPA) model (implemented in the INTEGRATION software) outperforms the Gipps (AIMSUM), Fritzsche (PARAMICS) and Wiedemann (VISSIM) models in generating accurate VSP distributions and fuel consumption and emission estimates. This demonstrates the advantage of the INTEGRATION model over the other three simulation models for energy and environmental analysis. A new eco-routing model, comprehensively considering microscopic characteristics, is then developed, followed by a numerical experiment to test the benefit of the model. With the resulting eco-routing model, an on-road vehicle dynamic eco-routing system is constructed for in-vehicle navigation applications, and tested for different congestion levels. The results of the study demonstrate that the proposed eco-routing model is able to generate reasonable routing suggestions based on real-time information while at the same time differentiate eco-routes between vehicle models. It is also found that the proposed dynamic eco-routing system achieves lower network-wide energy consumption levels compared to the traditional eco-routing and travel time routing at all congestion levels. The results also demonstrate that the conventional fuel savings relative to the travel time routing decrease with the increasing congestion level; however, the electric power savings do not monotonically vary with congestion level. Furthermore, the energy savings relative to the traditional eco-routing are also not monotonically related to congestion level. In addition, network configuration is demonstrated to significantly affect eco-routing benefits. The dissertation finally investigates the potential to influence driver behavior by studying the impact of information on route choice behavior based on a real world experiment. The results of the experiment demonstrate that the effectiveness of information in routing rationality depends upon the traveler's age, preferences, route characteristics, and information type. Specifically, information effect is less evident for elder travelers. Also, the provided information may not be contributing if travelers value other considerations or one route significantly outperforms the others. The results also demonstrate that, when travelers have limited experiences, strict information is more effective than variability information, and that the faster less reliable route is more attractive than the slower more reliable route; yet the difference becomes insignificant with experiences accumulation. The results of the study will be used to enhance system design through considering route choice incentives. / Ph. D.

O sistema de transporte tem importante papel para a dinâmica de uma cidade. Em São Paulo a partir do século XX o sistema viário passa a ser o principal elemento estruturador da cidade. Além de servir para o transporte urbano, este sistema serviu como base para a expansão urbana de São Paulo. No presente trabalho foi feita a análise do sistema viário estrutural paulistano. Foram analisados os planos urbanos entre 1930 a 2002 examinando suas propostas urbanas e suas diretrizes para o sistema viário. O Plano de Avenidas (1930) do engenheiro-urbanista Prestes Maia foi o primeiro plano de conjunto a estabelecer diretrizes para o sistema viário, englobando estas duas funções do sistema viário. O sistema viário radio-perimetral proposto neste plano repercutiu amplamente nas intervenções ao longo de todo o século XX. O conceito radioconcêntrico foi retomado em planos seguintes, mas houve uma tentativa de quebras deste paradigma no Plano Urbanístico Básico (1968) e Plano Diretor de Desenvolvimento Integrado (1971). Estes planos apresentaram o conceito de malha de vias expressas, um sistema totalmente independente do sistema viário existente, o qual diluiria o caráter mononuclear da metrópole. Dado as difíceis condições econômicas do período, o modelo não foi pra frente. Os planos seguintes priorizaram o transporte coletivo e para o sistema viário, retomaram o modelo radioconcêntrico. A partir da década de 1980, outro elemento passa a marcar o sistema viário paulistano: as avenidas de fundo de vale. Dada a falta de recursos para intervenções viárias, amparando-se no Plano Nacional de Saneamento, foram implantadas várias avenidas ao longo da canalização de corpos d´água. Também a partir da década de 1980 observa-se uma maior difusão das intervenções viárias. Antes concentradas na região central e o vetor sudoeste, neste período há uma ampliação na área de intervenção (sentido Norte e Leste). A descentralização destas intervenções viárias contribuiu para o desenvolvimento de centros locais dissociados ao núcleo central, o que havia sido proposto como estratégia urbanística para São Paulo desde 1958 com a publicação do estudo da SAGMACS. Desde a divulgação deste estudo, a descentralização urbana passou a ser integrar todos os planos urbanos propostos para a cidade com diferentes medidas estratégicas: desde o desenvolvimento de centros locais, até a descentralização política. Apesar disso, até o final do período estudado, continua a haver uma concentração de investimentos para obras de grande porte na região central e sudoeste. Segundo Villaça, em São Paulo as classes mais altas tendem a se concentrar no quadrante sudoeste do município, região a qual também se concentraram os investimentos públicos. Ainda segundo Villaça, uma vez que não obrigatoriedade de aplicação das diretrizes presentes no plano diretor, ele tem pouco servido para o equacionamento dos problemas urbanos e, na verdade, tem permitido a perpetuação de ações não igualitárias sobre o território urbano. / The transportation system plays an important role in the dynamics of a city. Since the beginning of the twentieth century, São Paulo´s road system has become the main structural element of the city. Besides serving for transportation, this system serves an important role for the urban growth of São Paulo. In this work São Paulo´s structural road system will be analyzed. It studies the city´s urban plans between 1930 to 2002 and examines proposals for urban planning and the guidelines for the road system. The Plano de Avenidas (1930) was the first urban plan to establish guidelines for the road system that assumed it´s importance as a growth structure as well as its function as mode of transportation. The radial-perimetral road system proposed in this plan resonated widely in the interventions in the system throughout the twentieth century. The Radioconcêntrico concept was taken up on later plans, although there was attempts to break this paradigm in Plano Urbanístico Básico (1968) and Plano Diretor de Desenvolvimento Integrado (1971). These plans presented the concept of expressways in form of a grid, a fully independent system from the existing road system, which would undo the heavy mononuclear aspect of the metropolis. Given the difficult economic conditions of the period, this new road system model did not go forward. The following plans prioritized public transport and the road system resumed to the radioconcêntrico model. Since the 1980s, another category of intervention marks the road system of São Paulo: the avenidas de fundo de vale. Given the lack of resources for interventions in the road system, several avenues were opened along canalized by use of the resources of a national sanitation plan (Plano Nacional de Saneamento). Also since the 1980s the road interventions had become more spread out then before. Until then a majority of the big road related intervention had concentrated in central and southwest quadrant. The decentralization of these roads interventions contributed to the development of local centers dissociated with historical city center. This descentralization had been proposed as a urban strategy for São Paulo since 1958 with the publication of the SAGMACS study. After the release of this study, urban decentralization became an important proposal in the urban plans for São Paulo. The descentralization strategies went from the development of local centers, to political decentralization. Nevertheless, by the end of the period analyzed in this study, there remains to be a concentration of in the central and southwest regions. According to Villaça, in São Paulo the upper classes tend to be concentrated in the southwest quadrant of the city, a region which also concentrated public investments. Also according to Villaça, since there is no mandatory application of the guidelines present in the master plan, this mechanism has not attended its purpose: the resolution of urban problems. It in fact, has allowed the perpetuation of non- egalitarian actions on the urban territory.

No Brasil existe a perspectiva de crescimento expressivo do volume de dados a ser processado pelas prestadoras de serviços de rastreamento em decorrência do aumento natural do uso de sistemas de rastreamento e também para atender a Resolução 330 de 2009 e Deliberação 135 de 30/01/2013 do Conselho Nacional de Trânsito (CONTRAN). Este crescimento gera a necessidade da incorporação de ferramentas analíticas nos sistemas de gerenciamento do rastreamento e monitoramento de veículos e na gestão de risco, para aumentar a sua eficiência e atender o crescimento do mercado. O objetivo desta dissertação é de propor uma metodologia que permita caracterizar o comportamento de movimentação de um veículo, com a finalidade de auxiliar o processo de tomada de decisão no gerenciamento e monitoramento de veículos. A caracterização do comportamento de movimentação do veículo foi feita pela geração de um modelo analítico do comportamento de movimentação, coletando os dados pretéritos da posição espacial e temporal. Este modelo baseia-se na movimentação e considera os aspectos comportamentais espaciais e temporais de forma independente. A caracterização do comportamento gera informações para identificar o comportamento espacial e temporal do veículo monitorado para um determinado nível de confiabilidade. / In Brazil there is the prospect of growth in the volume of data to be processed by the tracking service providers due to the natural increase of the use of tracking systems and also to meet the Resolution 330 of 2009 and Resolution 135 of 01.30.2013 of the National Traffic Council (CONTRAN), due to this growth the need of incorporation of analytical tools in systems management tracking and monitoring of vehicles and risk management are created, to increase their efficiency and meet market growth. This study objective is to propose a methodology to characterize the moving vehicle behavior, in order to assist the process of decision making in management and vehicle tagging. The vehicle handling behavior will be characterized by generating an analytical model of the vehicle movement, collecting bygone data of spatial position and time. This model will consist of a motion model taking into account that the spatial and temporal aspects of behavior are taken independently. The behavior characterization generates reports able to identify the spatial and temporal behavior of the monitored vehicle for a given level of reliability.

Made available in DSpace on 2016-07-27T14:20:26Z (GMT). No. of bitstreams: 1 Gardenia de Souza Furtado Lemos.pdf: 563104 bytes, checksum: e4de4fec8d54b9b6e10cbfb8819307b0 (MD5) Previous issue date: 2004-02-27 / The purpose of this study is to deal with the traffic issue as a complex social practice, and its intention is to raise and analyze the cognitive system produced by this practice on bus drivers of the conventional and alternative transportation metro system in the city of Goiania. Therefore, the study searched for the representative system that orients and justifies its conduction practices. The expected impact of this study was the contribution of a psychosocial model of traffic study, specifically of the metro transportation, thus, getting to know better how these groups represent reality. The metro transportation structure of the city of Goiania is constituted by the conventional system of metro transportation, where the vehicle used is the bus, and by one alternative metro system, that uses the microbus. To get to know the traffic representations of these groups and some particulars related to them, it was made a research which was methodologically oriented by the Theory of the Central Nucleus of the Social Representations. It was applied a questionnaire to 103 (one hundred and three) bus drivers and to 118 (one hundred eighteen) microbus drivers of the city of Goiania and its metropolitan region. The results indicated that both groups have a representation centered on the idea of tumult and stress , and a negative view of the behavior of others drivers. However, these representations are different when it is analyzed the meaning given to the elements that supposedly compose the central nucleus, which can illustrate the different work situation in the traffic of both groups interviewed. / Este trabalho objetivou tratar a questão do trânsito como uma prática social complexa, e teve a intenção de levantar e analisar o sistema cognitivo engendrado por essa prática em motoristas de transporte coletivo convencional e transporte alternativo na cidade de Goiânia. Assim, preocupou-se em conhecer o sistema representacional que orienta e justifica as suas práticas de condução. O impacto esperado deste trabalho foi de contribuir para um modelo psicossocial de estudo do trânsito, especificamente do transporte coletivo, conhecendo melhor como esses grupos representam a realidade. A estrutura de transporte coletivo de Goiânia é constituída pelo sistema convencional de transporte coletivo, cujo veículo utilizado é o ônibus, e por um sistema alternativo de transporte coletivo, que utiliza microônibus. Para conhecer as representações desses grupos sobre o trânsito e alguns fatores a ele relacionados, realizou-se uma pesquisa metodologicamente orientada pela Teoria do Núcleo Central das Representações Sociais. Foi aplicado um questionário em 103 (cento e três) sujeitos motoristas de ônibus e em 118 (cento e dezoito) sujeitos motoristas de microônibus da cidade de Goiânia e região metropolitana. Os resultados indicaram que os dois grupos têm uma representação centrada na idéia de tumulto e stress e uma visão negativa do comportamento dos outros motoristas. Contudo, essas representações são diferentes quando se analisa o significado atribuído aos elementos que supostamente compõem o núcleo central, ilustrando, como é diferente a situação do trânsito para os dois grupos entrevistados.

Le transport a toujours été l'un des composants déterminants de la vie urbaine et de son développement économique. A partir de la seconde moitié du siècle dernier, l'amélioration du niveau de vie moyen et du taux d'équipement des ménages a permis au plus grand nombre d'accéder au déplacement par véhicule particulier. Nous avons donc assisté à une course entre la croissance du trafic routier et les progrès quantitatifs et qualitatifs de la voirie. Cette quantité d'actions génère des problèmes au niveau de la fluidité du trafic, d'où l'apparition de congestion.La congestion se produit aujourd'hui de façon quasi-quotidienne dans les réseaux routiers. Elle est source de perte de temps, augmentation de la consommation d'énergie, nuisance et détérioration de l'environnement. La solution aux problèmes de congestion routière ne passe pas toujours par l'augmentation de l'investissement dans les infrastructures de transport. En effet, l'offre de terrains est épuisée et le développement de l'infrastructure routière est coûteux. D'où, la tendance actuelle est plutôt à une meilleure utilisation des infrastructures existantes. En particulier, les feux de signalisation jouent un rôle important parmi les approches qui permettent d'éviter la congestion. En effet, la conception d'une meilleur commande des feux de signalisation a fait l'objet de plusieurs recherches afin d’améliorer la circulation au niveau du réseau à grande échelle.Dans ce mémoire, nous nous intéressons essentiellement à un travail en amont (action a priori) permettant d'éviter la congestion en forçant le nombre de véhicules à ne pas dépasser les capacités maximales des voies du réseau de transport. Après avoir décrire les réseaux de carrefours des feux, nous présentons d'une manière non exhaustive, les méthodes développées pour la gestion et la régulation des carrefours. Ensuite, nous proposons trois stratégies de contrôle qui traitent le problème de contrôle de manières différentes. La première fait appel à la théorie des systèmes dissipatifs, la deuxième consiste à stabiliser le système au sens de Lyapunov autour de sa situation nominale et la troisième le stabilise en temps fini (pendant les heures de pointe). Ces commandes proposées respectent les contraintes sur l'état et sur la commande et prennent en considération les incertitudes existantes dans le système. Finalement, l'existence des commandes proposées a été caractérisée par la faisabilité de certaines LMI en utilisant l'outil CVX sous MATLAB. De plus, les performances de chaque commande sont évaluées par des simulations. / Transport has always been one of the key components of urban life and its economic development. From the second half of the last century, the improvement in the average standard of living and the household equipment rate allowed the greatest number of people to access the journey by private vehicle. We therefore witnessed a race between the growth of road traffic and the quantitative and qualitative progress of roads. This quantity of actions generates problems with the fluidity of the traffic, hence the appearance of congestion.The congestion occurs today almost daily in road networks. It is source of waste of time, increase of the energy consumption, the nuisance and the deterioration of the environment. The solution to the problems of road congestion does not still pass by the increase of the investment in the infrastructures of transport. Indeed, the offer of grounds is exhausted and the development of the road infrastructure is expensive. Hence, the current trend is rather for a better use of the existing infrastructures. In particular, traffic lights play an important role in avoiding congestion. Indeed, the design of a better control of traffic lights has been the subject of several researches in order to improve the network circulation on a large scale.In this thesis, we are mainly interested in a work that prevents the congestion by forcing the number of vehicles to not exceed the lane capacities. After having described the network of intersections, we have realized a state of the art on the methods developed for the management and regulation of intersections. Next, we propose three control strategies that treat the control problem in different ways. The first one involves the theory of dissipative systems, the second one is to stabilize the system in the sense of Lyapunov around its nominal situation and the third one stabilizes it in finite time (during peak hours). These proposed controls respect the constraints on both state and control. In addition, they take into account the uncertainties in the system. Finally, the result of each strategy developed is presented by LMI in order to be solved by using the CVX tool under MATLAB. Besides, the performance of each control is evaluated by simulations.

Kaohsiung area has the excellent geographical position, eliminates has the deep water port which the transportation amount is among the best, also the international airport simultaneously has the shortest average distance with the neighbor country, not only the peripheral region correlation industry foundation is abundant, it really has the potential to develop "the Global Logistic Center" on behalf of Taiwan. But in the pass, Taiwan in both shore policy, the industrial policy, under the correlation law intriguing, creates the Kaohsiung double port area development to be unbalanced, also faces Mainland China and the Southeast Asia area, local city and so on and also South Korean Pusan¡¦s astringently challenge, therefore draining of the Kaohsiung double port competitive ability is becomes inevitably. Therefore, motive of this research, namely emphatically in: Kaohsiung has the sea and air double port condition, analyzes the region industry development and the global logistic tendency of, and establishes Kaohsiung to develop into the Global Logistic Center foundation.

In the first study, three different transport systems for bacteria were evaluated. The CLSI M40-A guideline was used to monitor the maintenance of both mono- and polymicrobial samples during a simulated transportation at room temperature that lasted 0-48 h. All systems were able to maintain the viability of all organisms for 24 h, but none of them could support all tested species after 48 h.  The most difficult species to recover was Neisseria gonorrhoeae, and in polymicrobial samples overgrowth was an observed problem. The aim of the second study was to study the presence of TSST-1 and three other important toxin genes in invasive isolates of Staphylococcus aureus collected during the years 2000-2012 at two tertiary hospitals. The genes encoding the staphylococcal toxins were detected by PCR, and whole-genome sequencing was used for analyzing the genetic relatedness between isolates. The results showed that the most common toxin was TSST-1, and isolates positive for this toxin exhibited a clear clonality independent of year and hospital. The typical patient was a male aged 55-74 years and with a bone or a joint infection. The third study was a clinical study of the effect of silver-based wound dressings on the bacterial flora in chronic leg ulcers. Phenotypic and genetic silver-resistance were investigated before and after topical silver treatment, by determining the silver nitrate MICs and by detecting sil genes with PCR. The silver-based dressings had a limited effect on primary wound pathogens, and the activity of silver nitrate on S. aureus was mainly bacteriostatic. A silver-resistant Enterobacter cloacae strain was identified after only three weeks of treatment, and cephalosporin-resistant members of the Enterobacteriaceae family were relatively prone to developed silver-resistance after silver exposure in vitro. The last study was undertaken in order to develop an easy-to-use method for simulating the laundering process of hospital textiles, and apply the method when evaluating the decontaminating efficacy of two different washing temperatures. The laundering process took place at professional laundries, and Enterococcus faecium was used as a bioindicator. The results showed that a lowering of the washing temperature from 70°C to 60°C did not affect the decontamination efficacy; the washing cycle alone reduced the number of bacteria with 3-5 log10 CFU, whereas the following tumble drying reduced the bacterial numbers with another 3-4 log10 CFU, yielding the same final result independent of the washing temperature. To ensure that sufficient textile hygiene is maintained, the whole laundering process needs to be monitored. The general conclusion is that all developmental work in the bacterial field requires time and a large strain collection.

The automotive domain is changing. On the way to more convenient, safe, and efficient vehicles, the role of electronic controllers and particularly software has increased significantly for many years, and vehicles have become software-intensive systems. Furthermore, vehicles are connected to the Internet to enable Advanced Driver Assistance Systems and enhanced In-Vehicle Infotainment functionalities. This widens the automotive software and system landscape beyond the physical vehicle boundaries to presently include as well external backend servers in the cloud. Moreover, the connectivity facilitates new kinds of distributed functionalities, making the vehicle a part of an Intelligent Transportation System (ITS) and thus an important example for a future Internet of Things (IoT). Manufacturers, however, are confronted with the challenging task of integrating these ever-increasing range of functionalities with heterogeneous or even contradictory requirements into a homogenous overall system. This requires new software platforms and architectural approaches. In this regard, the connectivity to fixed side backend systems not only introduces additional challenges, but also enables new approaches for addressing them. The vehicle-to-backend approaches currently emerging are dominated by proprietary solutions, which is in clear contradiction to the requirements of ITS scenarios which call for interoperability within the broad scope of vehicles and manufacturers. Therefore, this research aims at the development and propagation of a new concept of a universal distributed Automotive Service Delivery Platform (ASDP), as enabler for future automotive functionalities, not limited to ITS applications. Since Machine-to-Machine communication (M2M) is considered as a primary building block for the IoT, emergent standards such as the oneM2M service platform are selected as the initial architectural hypothesis for the realisation of an ASDP. Accordingly, this project describes a oneM2M-based ASDP as a reference configuration of the oneM2M service platform for automotive environments. In the research, the general applicability of the oneM2M service platform for the proposed ASDP is shown. However, the research also identifies shortcomings of the current oneM2M platform with respect to the capabilities needed for efficient communication and data exchange policies. It is pointed out that, for example, distributed traffic efficiency or vehicle maintenance functionalities are not efficiently treated by the standard. This may also have negative privacy impacts. Following this analysis, this research proposes novel enhancements to the oneM2M service platform, such as application-data-dependent criteria for data exchange and policy aggregation. The feasibility and advancements of the newly proposed approach are evaluated by means of proof-of-concept implementation and experiments with selected automotive scenarios. The results show the benefits of the proposed enhancements for a oneM2M-based ASDP, without neglecting to indicate their advantages for other domains of the oneM2M landscape where they could be applied as well.

O sistema de transporte tem importante papel para a dinâmica de uma cidade. Em São Paulo a partir do século XX o sistema viário passa a ser o principal elemento estruturador da cidade. Além de servir para o transporte urbano, este sistema serviu como base para a expansão urbana de São Paulo. No presente trabalho foi feita a análise do sistema viário estrutural paulistano. Foram analisados os planos urbanos entre 1930 a 2002 examinando suas propostas urbanas e suas diretrizes para o sistema viário. O Plano de Avenidas (1930) do engenheiro-urbanista Prestes Maia foi o primeiro plano de conjunto a estabelecer diretrizes para o sistema viário, englobando estas duas funções do sistema viário. O sistema viário radio-perimetral proposto neste plano repercutiu amplamente nas intervenções ao longo de todo o século XX. O conceito radioconcêntrico foi retomado em planos seguintes, mas houve uma tentativa de quebras deste paradigma no Plano Urbanístico Básico (1968) e Plano Diretor de Desenvolvimento Integrado (1971). Estes planos apresentaram o conceito de malha de vias expressas, um sistema totalmente independente do sistema viário existente, o qual diluiria o caráter mononuclear da metrópole. Dado as difíceis condições econômicas do período, o modelo não foi pra frente. Os planos seguintes priorizaram o transporte coletivo e para o sistema viário, retomaram o modelo radioconcêntrico. A partir da década de 1980, outro elemento passa a marcar o sistema viário paulistano: as avenidas de fundo de vale. Dada a falta de recursos para intervenções viárias, amparando-se no Plano Nacional de Saneamento, foram implantadas várias avenidas ao longo da canalização de corpos d´água. Também a partir da década de 1980 observa-se uma maior difusão das intervenções viárias. Antes concentradas na região central e o vetor sudoeste, neste período há uma ampliação na área de intervenção (sentido Norte e Leste). A descentralização destas intervenções viárias contribuiu para o desenvolvimento de centros locais dissociados ao núcleo central, o que havia sido proposto como estratégia urbanística para São Paulo desde 1958 com a publicação do estudo da SAGMACS. Desde a divulgação deste estudo, a descentralização urbana passou a ser integrar todos os planos urbanos propostos para a cidade com diferentes medidas estratégicas: desde o desenvolvimento de centros locais, até a descentralização política. Apesar disso, até o final do período estudado, continua a haver uma concentração de investimentos para obras de grande porte na região central e sudoeste. Segundo Villaça, em São Paulo as classes mais altas tendem a se concentrar no quadrante sudoeste do município, região a qual também se concentraram os investimentos públicos. Ainda segundo Villaça, uma vez que não obrigatoriedade de aplicação das diretrizes presentes no plano diretor, ele tem pouco servido para o equacionamento dos problemas urbanos e, na verdade, tem permitido a perpetuação de ações não igualitárias sobre o território urbano. / The transportation system plays an important role in the dynamics of a city. Since the beginning of the twentieth century, São Paulo´s road system has become the main structural element of the city. Besides serving for transportation, this system serves an important role for the urban growth of São Paulo. In this work São Paulo´s structural road system will be analyzed. It studies the city´s urban plans between 1930 to 2002 and examines proposals for urban planning and the guidelines for the road system. The Plano de Avenidas (1930) was the first urban plan to establish guidelines for the road system that assumed it´s importance as a growth structure as well as its function as mode of transportation. The radial-perimetral road system proposed in this plan resonated widely in the interventions in the system throughout the twentieth century. The Radioconcêntrico concept was taken up on later plans, although there was attempts to break this paradigm in Plano Urbanístico Básico (1968) and Plano Diretor de Desenvolvimento Integrado (1971). These plans presented the concept of expressways in form of a grid, a fully independent system from the existing road system, which would undo the heavy mononuclear aspect of the metropolis. Given the difficult economic conditions of the period, this new road system model did not go forward. The following plans prioritized public transport and the road system resumed to the radioconcêntrico model. Since the 1980s, another category of intervention marks the road system of São Paulo: the avenidas de fundo de vale. Given the lack of resources for interventions in the road system, several avenues were opened along canalized by use of the resources of a national sanitation plan (Plano Nacional de Saneamento). Also since the 1980s the road interventions had become more spread out then before. Until then a majority of the big road related intervention had concentrated in central and southwest quadrant. The decentralization of these roads interventions contributed to the development of local centers dissociated with historical city center. This descentralization had been proposed as a urban strategy for São Paulo since 1958 with the publication of the SAGMACS study. After the release of this study, urban decentralization became an important proposal in the urban plans for São Paulo. The descentralization strategies went from the development of local centers, to political decentralization. Nevertheless, by the end of the period analyzed in this study, there remains to be a concentration of in the central and southwest regions. According to Villaça, in São Paulo the upper classes tend to be concentrated in the southwest quadrant of the city, a region which also concentrated public investments. Also according to Villaça, since there is no mandatory application of the guidelines present in the master plan, this mechanism has not attended its purpose: the resolution of urban problems. It in fact, has allowed the perpetuation of non- egalitarian actions on the urban territory.