Master of Science

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The application of Visualization and Simulation technologies to intuitively depict, analyze and execute transportation projects is gaining momentum, as advances in 3-Dimension (3D) Geographic Information Systems (GIS) technologies are rapidly progressing and there is an increased need for public acceptance of transportation projects. This thesis presents a visualization process framework that is applicable to highway corridor visualization, and the I-77/81 Relocation Study Visualization project is discussed along the lines of the visualization framework that has been developed. The changes in the roadway alignment and associated traffic volume and pattern changes will affect the town of Wytheville, both in terms of economy and community development. The goal of the project is to present these visualizations at public participation meetings. Visualizations that have been developed in 2D, 3D, 4D, and virtual reality, will be discussed along with their developmental life cycles and issues affecting their quality. / Master of Science

The non-recurring congestion, caused by incidents, is the main cause of traffic delays and causes up to 60 percent of the freeway delay in the United States. When severe incidents occur on freeways, capacity reduction due to lane blockages may cause an extremely high amount of traffic delay. In many cases, parallel surface arterials are available, and provide reasonably high speed and available capacity. In this scenario, to fully utilize the corridor capacity, diversion may be practical and necessary. With the changes of traffic demand levels and patterns on surface streets due to diversion, signal retiming for surface street intersections is necessary. A nonlinear programming model was formulated to provide an integrated traffic control strategy for a freeway corridor under incident conditions. The objective function of the optimization model considers the interactions among the corridor components, and clearly reflects the primary goals of corridor traffic control under freeway incident conditions: to divert as much traffic away from the freeway as possible, not to over-congest the arterial and surface streets; and properly reset the signal timing plans at all intersections to accommodate the changed traffic demand levels and patterns. The gradient projection method is employed to solve diversion and signal retiming control measures simultaneously. By using a specifically developed simple and realistic traffic flow model and employing a sequential optimization approach, the computer program COROPT can obtain optimal traffic control strategies quickly and effectively. The COROPT program also has the flexibility to deal with various corridor configurations, different size of the corridor system, and different timing phasings. The model can address the time-varying factor of traffic flow, and can handle changing traffic and incident conditions over the time. The model performance was evaluated and validated by running the simulation and optimization programs of TRANSYT-7F and INTEGRATION. It has been found that the proposed model and control strategy reduce the overall system delay, increase the throughput of the corridor, and thus improve the traffic conditions of the entire corridor. / Ph. D.

The United States relies on its vast network of roadways to transport people, goods, and services across the nation. These roads need to be maintained to an acceptable level in order to effectively provide a safe, reliable, and efficient road. The use of infrastructure management systems (IMS) has aided in keeping an inventory of existing roads, identifying assets in need of repair, and assisting in allocating funds for maintenance, repair, and rehabilitation. The current practice in the United States has shown a lack of consistency in the way assets are rated in each state. Individual states have employed their own methodology for rating each asset type. This makes comparison of assets between states difficult. Several methods in use have provided a way to effectively rate an asset, but no method exists that can be used to compare ratings in different states. To successfully maintain the network of roads across the United States, a method to assess assets between states is necessary. Consistency between states in their data collection, rating calculation, and rating reporting are all necessary to identify poor sections of roadway. Another useful reporting item will be a condition rating of all the assets contained within a corridor. A corridor is a series of travel routes which move people between two major points of interest. By analyzing corridor level condition ratings, it will be possible to examine the overall condition of all the corridor sections across the nation and identify sections that need assistance in raising their condition. The objective of this thesis was to develop a framework for rating assets at the corridor level. The framework was developed to be applied to any asset contained within a roadway and allow the combination of individual asset ratings into a single corridor rating. The final methodology not only reports the overall corridor condition, but the functional and structural health of each individual asset, the rating of all of an asset type within a corridor, and performance indicators for individual items on a single asset. The methodology was tested using data provided by the Virginia Department of Transportation (VDOT) to test if the methodology would produce ratings similar to those in use. For the application methods were developed for two major roadway assets; pavements and bridges. The product of this thesis is a general framework which can be applied to roadway corridors to assess the overall condition of all the assets contained within the corridor's boundaries. It can be used in conjunction with an IMS to help improve and maintain the overall condition of the roads, which are critical to the United States. Without unification of condition rating methods into a single method it will never be possible to compare assets from every state in the nation. / Master of Science

Infrastructure and open space planning can be brought together to create a system of multiuse corridors that accommodate multiple types of infrastructure, recreation trails and open space, while protecting natural resources. Some of the potential benefits of this system is more efficient use of fewer utility easements, a more comprehensive open space system that can be paid for by utility users, and less environmental damage from utility placement. A multiuse corridor planning process is described that is meant to be used by a multiple disciplinary team to plan for infrastructure and open space in the context of town, city or region. This process inventories all human infrastructure such as roads, waterlines, and electric and natural infrastructure, such as streams, rivers, forests, wetlands, and geologic features. An assessment is made on what areas are most likely to need infrastructure in the future and a conceptual plan is put together to best serve those needs. A conceptual open space plan is created to serve the needs of future development areas. The infrastructure and the open space plans are woven together using routing guidelines and typical multiuse corridor sections to best design these multiuse corridors. This thesis brings together infrastructure and open space planning at the city and regional level. / Master of Landscape Architecture

The red imported fire ant, Solenopsis invicta, is an abundant and aggressive component of early-successional communities in the southeastern United States. After disturbance, it rapidly invades new habitats, and once there, it has strong competitive and predatory effects on the existing arthropod community. In upland coastal plain pine forests at the Savannah River Site in South Carolina, I conducted two studies of fire ant ecology. In my first study (chapter 1), I investigated the way in which fire ants colonize early-successional road and powerline cuts through forests, and I tested whether some of these linear habitats provided better fire ant habitat than others. I found that fire ant mound density (#/ha) was similar in narrow dirt roads and in wider roads with the same intermediate level of mowing disturbance, and that density was lower in wide powerline cuts where the vegetation is only removed every five years. Furthermore, mound density was greatest near the edges of cleared roads and powerline cuts and was also greater on the northern sides of roads and powerline cuts where there was less shading from the adjacent forest. Results from this study suggest that allowing increased shading from adjacent forest vegetation, especially along northern roadside edges, would limit the suitability of road and powerline cuts as fire ant habitat, thereby slowing invasion. In my second study (chapter 2), I examined the impact of fire ants on arthropod and plant species in early-successional forest gaps. In a tritrophic system, I tested whether the top-down effect of insect herbivore consumption by fire ants was strong enough to cascade through two trophic levels and improve plant growth and fitness. I compared this potential effect to that of other arthropod predators in the community. I found that fire ants controlled the level of tissue damage to plant leaves by herbivores, but that the damage was not severe enough to influence plant growth or fitness. Fire ants had stronger negative interactions with insect herbivores than other predators in the community, and for this reason, fire ants can be considered keystone predators. This project provides further evidence that fire ants successfully invade even small patches of early-successional habitat that exist within larger matrices of uninhabitable, late-successional forest, and that once there, they have a dramatic effect on the arthropod community. Restricting the amount of early-successional habitat within southeastern forests, either as permanent road and powerline cuts or as temporary gaps, would limit the potential for strong and detrimental effects by the invasive fire ant. / Master of Science

The practice of double-loaded corridors and circulation cores only serves to segregate spaces and develops no relationship between one space and another. In a contemporary society based on human interactions, should the conduit for delivering human-to-human connections be confined simply to notions of “horizontal circulation” and “vertical circulation”? Do we deserve better? This thesis proposes that a measure of continuity can unify disparate spaces. This continuous architecture can join these spaces in series resulting in an instant and direct relationship of one space to another. Continuity can facilitate not only the interaction of spaces but also the interaction between occupants. / Master of Architecture

A fragmentação de habitats em muitos casos limita o potencial de dispersão das espécies. Por esta razão, muitas iniciativas visando à conservação de espécies em paisagens fragmentadas envolvem o delineamento de corredores ecológicos entre manchas de hábitat. Neste trabalho, foi modelado um sistema de corredores entre manchas de mata remanescentes no mosaico urbano-rural de uma grande cidade no sul do Brasil (Porto Alegre, RS), tendo como organismo focal o primata Alouatta clamitans (bugio-ruivo) que está ameaçado de extinção. Nossos objetivos específicos são (a) demonstrar a importância dá conectividade para a presença das populações de bugio-ruivo nos fragmentos florestais em Porto Alegre; (b) detectar os fragmentos mais importantes para manter a conectividade funcional potencial da espécie; (c) desenhar um sistema de corredores potenciais, considerando a capacidade de dispersão do bugio-ruivo em diferentes tipos de manchas de paisagem e (d) propor um método para avaliação da qualidade de corredores, levando em consideração a variação do atrito à dispersão ao longo do traçado dos corredores e a existência de pontos críticos de vulnerabilidade ao longo dos corredores. A vulnerabilidade foi avaliada em função da paisagem vizinha a cada corredor, entendendo-se como vulnerabilidade a probabilidade de futura modificação ou interrupção do corredor devido a mudanças na paisagem vizinha. Foi verificada a existência da relação da conectividade funcional com a presença da espécie nos fragmentos florestais através do índice Integral index of connectivity - IIC. Através da porcentagem de importância do mesmo índice (dIIC) para cada fragmento arbóreo, identificou-se o morro São Pedro como mais importante para a manutenção da conectividade da paisagem. Além do morro São Pedro foram selecionados os fragmentos arbóreos maiores que 10 ha para a modelar corredores utilizando o algoritmo do caminho de menor custo. Utilizou-se dois parâmetros: grau de antropização que avalia o potencial de persistência dos corredores e o atrito que simula a resistência dos habitats ao deslocamento da espécie. Esses parâmetros foram utilizados nas análises de fracionamento para quantificar o número de interrupções no corredor e a qualidade do habitat interno. Os resultados da análise de fracionamento e a extensão foram usados na classificação de qualidade de cada corredor. Foram gerados 136 corredores com extensão entre 4 m e 4128 m, Observou-se que corredores com mais de 1000 m tendem a ser potencialmente mais fracionados. Setenta e três corredores mantiveram-se contínuos segundo o potencial de persistência. A análise da qualidade do habitat revelou que 120 corredores foram fracionados. A área total de habitat efetivo (classe arbórea/arbustiva) para o deslocamento foi reduzida em 41%. A análise de qualidade global revelou que 32% dos corredores são bons, 51% são medianos e 16,2% são ruins. O potencial de persistência revelou-se um método promissor de avaliar o potencial de alteração que o entorno tem em relação ao corredor. A análise de qualidade de habitat mostrou-se eficiente para identificar os corredores lineares de hábitat ou íntegros. O método pode auxiliar na tomada de decisão do custo-beneficio para investir em gestão e manejo de corredores lineares multi-habitat. / Habitat fragmentation limits possibility of species dispersai. Many initiatives aim at species conservation in fragmented landscapes involve the delineation of ecological corridors among habitat patches. Here, we modeled a corridor system among remnant forest fragments in the urban-rural mosaic of a large city in southern Brazil (Porto Alegre, RS), using the endangered primate Alouatta clamitans (brown-howler-monkey) as a focal species. Our specific aims were (a) to demonstrate the importance of connectivity for the presence of the brown-howler monkey in forest fragments; (b) to identify the most important fragments for maintenance of potential functional connectivity for the species; (c) to draw a potential corridor system, considering the species dispersai capacity in different habitat patches; and (d) to propose a new method of corridor quality evaluation, considering friction variation to disperse along corridors and the existence of vulnerable criticai points for the persistence of corridors. Vulnerability was evaluated in terms of neighboring landscape of each corridor (context), being defined as the probability of future corridor modification or interruption due to changes in the neighboring landscape. We examined the existence of a positive relation between functional connectivity and the species presence in forest fragments using the Probability of Connectivity index (dIPC). We identified the São Pedro hill as the most important area for the maintenance of landscape connectivity based on the dIPC. In addition to São Pedro hill, we selected the forest fragmentes larger than 10 hectares to model corridors using the least-cost distance algorithm. To assess vulnerability, we used two parameters: the antropization degree, which is a proxy for potential of corridor persistence, and the friction degree, which is a proxy for habitat resistance to the species dispersal. These parameters were used to examine the fractioning of corridors, that is, to quantify the number of actual or potential interruptions in corridor trajectory and its inner habitat quality. The results of the fractioning analyses and the corridor extension were used as attributes for ranking ali corridors in terms of quality. We generated 136 corridors with an extension between 4 m and 4128 m. Corridors with more than 1000 m tended to be potentially more fractioned, while seventy three corridors were kept uninterrupted according to persistence potential. Habitat quality analysis revealed that 120 corridors were fractioned. Total area of effective habitat (arboreal/shrubby class) to movements was reduced in 41%. The global quality analysis revealed that 32% of corridors are good, 51% are median and 16.2% are bad. Persistence potential appears to be a promising method to evaluate the potential for antropogenic modification imposed on corridors by their surrounding landscape. This method cari help in cost-benefit decision making for management of multi-habitat linear corridors.

A fragmentação de habitats em muitos casos limita o potencial de dispersão das espécies. Por esta razão, muitas iniciativas visando à conservação de espécies em paisagens fragmentadas envolvem o delineamento de corredores ecológicos entre manchas de hábitat. Neste trabalho, foi modelado um sistema de corredores entre manchas de mata remanescentes no mosaico urbano-rural de uma grande cidade no sul do Brasil (Porto Alegre, RS), tendo como organismo focal o primata Alouatta clamitans (bugio-ruivo) que está ameaçado de extinção. Nossos objetivos específicos são (a) demonstrar a importância dá conectividade para a presença das populações de bugio-ruivo nos fragmentos florestais em Porto Alegre; (b) detectar os fragmentos mais importantes para manter a conectividade funcional potencial da espécie; (c) desenhar um sistema de corredores potenciais, considerando a capacidade de dispersão do bugio-ruivo em diferentes tipos de manchas de paisagem e (d) propor um método para avaliação da qualidade de corredores, levando em consideração a variação do atrito à dispersão ao longo do traçado dos corredores e a existência de pontos críticos de vulnerabilidade ao longo dos corredores. A vulnerabilidade foi avaliada em função da paisagem vizinha a cada corredor, entendendo-se como vulnerabilidade a probabilidade de futura modificação ou interrupção do corredor devido a mudanças na paisagem vizinha. Foi verificada a existência da relação da conectividade funcional com a presença da espécie nos fragmentos florestais através do índice Integral index of connectivity - IIC. Através da porcentagem de importância do mesmo índice (dIIC) para cada fragmento arbóreo, identificou-se o morro São Pedro como mais importante para a manutenção da conectividade da paisagem. Além do morro São Pedro foram selecionados os fragmentos arbóreos maiores que 10 ha para a modelar corredores utilizando o algoritmo do caminho de menor custo. Utilizou-se dois parâmetros: grau de antropização que avalia o potencial de persistência dos corredores e o atrito que simula a resistência dos habitats ao deslocamento da espécie. Esses parâmetros foram utilizados nas análises de fracionamento para quantificar o número de interrupções no corredor e a qualidade do habitat interno. Os resultados da análise de fracionamento e a extensão foram usados na classificação de qualidade de cada corredor. Foram gerados 136 corredores com extensão entre 4 m e 4128 m, Observou-se que corredores com mais de 1000 m tendem a ser potencialmente mais fracionados. Setenta e três corredores mantiveram-se contínuos segundo o potencial de persistência. A análise da qualidade do habitat revelou que 120 corredores foram fracionados. A área total de habitat efetivo (classe arbórea/arbustiva) para o deslocamento foi reduzida em 41%. A análise de qualidade global revelou que 32% dos corredores são bons, 51% são medianos e 16,2% são ruins. O potencial de persistência revelou-se um método promissor de avaliar o potencial de alteração que o entorno tem em relação ao corredor. A análise de qualidade de habitat mostrou-se eficiente para identificar os corredores lineares de hábitat ou íntegros. O método pode auxiliar na tomada de decisão do custo-beneficio para investir em gestão e manejo de corredores lineares multi-habitat. / Habitat fragmentation limits possibility of species dispersai. Many initiatives aim at species conservation in fragmented landscapes involve the delineation of ecological corridors among habitat patches. Here, we modeled a corridor system among remnant forest fragments in the urban-rural mosaic of a large city in southern Brazil (Porto Alegre, RS), using the endangered primate Alouatta clamitans (brown-howler-monkey) as a focal species. Our specific aims were (a) to demonstrate the importance of connectivity for the presence of the brown-howler monkey in forest fragments; (b) to identify the most important fragments for maintenance of potential functional connectivity for the species; (c) to draw a potential corridor system, considering the species dispersai capacity in different habitat patches; and (d) to propose a new method of corridor quality evaluation, considering friction variation to disperse along corridors and the existence of vulnerable criticai points for the persistence of corridors. Vulnerability was evaluated in terms of neighboring landscape of each corridor (context), being defined as the probability of future corridor modification or interruption due to changes in the neighboring landscape. We examined the existence of a positive relation between functional connectivity and the species presence in forest fragments using the Probability of Connectivity index (dIPC). We identified the São Pedro hill as the most important area for the maintenance of landscape connectivity based on the dIPC. In addition to São Pedro hill, we selected the forest fragmentes larger than 10 hectares to model corridors using the least-cost distance algorithm. To assess vulnerability, we used two parameters: the antropization degree, which is a proxy for potential of corridor persistence, and the friction degree, which is a proxy for habitat resistance to the species dispersal. These parameters were used to examine the fractioning of corridors, that is, to quantify the number of actual or potential interruptions in corridor trajectory and its inner habitat quality. The results of the fractioning analyses and the corridor extension were used as attributes for ranking ali corridors in terms of quality. We generated 136 corridors with an extension between 4 m and 4128 m. Corridors with more than 1000 m tended to be potentially more fractioned, while seventy three corridors were kept uninterrupted according to persistence potential. Habitat quality analysis revealed that 120 corridors were fractioned. Total area of effective habitat (arboreal/shrubby class) to movements was reduced in 41%. The global quality analysis revealed that 32% of corridors are good, 51% are median and 16.2% are bad. Persistence potential appears to be a promising method to evaluate the potential for antropogenic modification imposed on corridors by their surrounding landscape. This method cari help in cost-benefit decision making for management of multi-habitat linear corridors.