Thesis (M.A. in City and Regional Planning)--University of California, Berkeley, Fall 2005. / Title from PDF title page (viewed Dec. 13, 2007). "Fall 2005." Includes bibliographical references (p. 81-87).

A prioridade aos sistema de transporte coletivo por ônibus gera inúmeros benefícios operacionais, como menores tempos de viagem, velocidades operacionais mais elevadas, proporcionando, também, melhores condições aos usuários nos seus deslocamentos. Apresenta-se uma caracterização geral de 374 corredores prioritários ao ônibus, incluindo sistemas BRT (Bus Rapid Transit), BHLS (Bus with High Level of Service) e corredores com segregação viária. Análises de clusterização foram usadas para encontrar similaridades entre os diferentes corredores e resultaram na formação de quatro grupos. Verificou-se que as dez características com maior influência para a formação dos agrupamentos consistem de características físicas e operacionais dos corredores. Foi possível identificar características próprias para cada um dos clusters. Para entender o impacto de diferentes elementos de projeto e desempenho dos corredores na velocidade operacional realizou-se análises de relação entre variáveis. / The priority of public transport, more specifically bus systems, generates numerous operational benefits, such as lower travel times, higher operating speeds, as well as offering better conditions for users. A general characterization of the 374 bus priority corridors is presented, including BRT systems (Bus Rapid Transit), BHLS (Bus with High Level of Service) and segregated bus priority corridors. Clustering analyses was used to find out similarities between the different corridors and resulted in the formation of four groups. It was found that the ten most influential characteristics for the formation of the 4 groups consisted of physical and operational characteristics of the corridors. It was possible to identify set of characteristics for each one of the clusters. Relationship between the variables was used to understand the impact of different design elements and performance of bus priority corridors in terms of operational speed.

A prioridade aos sistema de transporte coletivo por ônibus gera inúmeros benefícios operacionais, como menores tempos de viagem, velocidades operacionais mais elevadas, proporcionando, também, melhores condições aos usuários nos seus deslocamentos. Apresenta-se uma caracterização geral de 374 corredores prioritários ao ônibus, incluindo sistemas BRT (Bus Rapid Transit), BHLS (Bus with High Level of Service) e corredores com segregação viária. Análises de clusterização foram usadas para encontrar similaridades entre os diferentes corredores e resultaram na formação de quatro grupos. Verificou-se que as dez características com maior influência para a formação dos agrupamentos consistem de características físicas e operacionais dos corredores. Foi possível identificar características próprias para cada um dos clusters. Para entender o impacto de diferentes elementos de projeto e desempenho dos corredores na velocidade operacional realizou-se análises de relação entre variáveis. / The priority of public transport, more specifically bus systems, generates numerous operational benefits, such as lower travel times, higher operating speeds, as well as offering better conditions for users. A general characterization of the 374 bus priority corridors is presented, including BRT systems (Bus Rapid Transit), BHLS (Bus with High Level of Service) and segregated bus priority corridors. Clustering analyses was used to find out similarities between the different corridors and resulted in the formation of four groups. It was found that the ten most influential characteristics for the formation of the 4 groups consisted of physical and operational characteristics of the corridors. It was possible to identify set of characteristics for each one of the clusters. Relationship between the variables was used to understand the impact of different design elements and performance of bus priority corridors in terms of operational speed.

A prioridade aos sistema de transporte coletivo por ônibus gera inúmeros benefícios operacionais, como menores tempos de viagem, velocidades operacionais mais elevadas, proporcionando, também, melhores condições aos usuários nos seus deslocamentos. Apresenta-se uma caracterização geral de 374 corredores prioritários ao ônibus, incluindo sistemas BRT (Bus Rapid Transit), BHLS (Bus with High Level of Service) e corredores com segregação viária. Análises de clusterização foram usadas para encontrar similaridades entre os diferentes corredores e resultaram na formação de quatro grupos. Verificou-se que as dez características com maior influência para a formação dos agrupamentos consistem de características físicas e operacionais dos corredores. Foi possível identificar características próprias para cada um dos clusters. Para entender o impacto de diferentes elementos de projeto e desempenho dos corredores na velocidade operacional realizou-se análises de relação entre variáveis. / The priority of public transport, more specifically bus systems, generates numerous operational benefits, such as lower travel times, higher operating speeds, as well as offering better conditions for users. A general characterization of the 374 bus priority corridors is presented, including BRT systems (Bus Rapid Transit), BHLS (Bus with High Level of Service) and segregated bus priority corridors. Clustering analyses was used to find out similarities between the different corridors and resulted in the formation of four groups. It was found that the ten most influential characteristics for the formation of the 4 groups consisted of physical and operational characteristics of the corridors. It was possible to identify set of characteristics for each one of the clusters. Relationship between the variables was used to understand the impact of different design elements and performance of bus priority corridors in terms of operational speed.

Com o crescimento da população em áreas urbanas, o transporte coletivo assume um importante papel nos deslocamentos diários nas cidades brasileiras. No entanto, o grande volume de pessoas no entorno desses sistemas podem resultar em pontos críticos de segurança viária. Recentemente, as pesquisas sobre melhorias na segurança viária estão se direcionando para a investigação da relação entre o ambiente construído - isto é, padrões de uso do solo; desenho urbano; e sistemas de transporte - e acidentalidade. Porém, a relação entre os sistemas de transporte coletivo por ônibus e o ambiente construído ainda é pouco explorada. O ponto mais crítico em segurança identificado na literatura em sistemas de transporte coletivo são as estações de embarque e desembarque. Assim, esta dissertação tem como objetivo verificar a existência de relação entre elementos do ambiente construído com a ocorrência e severidade de acidentes viários no entorno de pontos de parada em sistemas prioritários para ônibus. Para isso, aplicou-se os modelos de regressão Binomial Negativo (NB), na análise de frequência de acidentes, e os modelos Logit Ordenado (OL) e Logit Multinomial (MNL), para a análise de severidade. No modelo de frequência de acidentes totais, identificou-se duas variáveis significativas e, no modelo estimado para atropelamentos, três variáveis. O modelo de severidade resultou em 19 variáveis significativas para acidentes totais e oito variáveis significativas para atropelamentos. As variáveis referentes ao envolvimento de motocicletas, automóveis, presença de interseção e uso diversificado do solo foram as mais recorrentes. O estudo possibilitou também avaliar as diferenças e vantagens entre os modelos ordenados e os não-ordenados. O modelo Logit Multinomial teve ajustes levemente melhores do que o Logit Ordenado. Ressalta-se, entretanto, que o ajuste do modelo não deve ser o único critério a se considerar na escolha de modelos para o estudo de severidade de acidentes. / Public transport has played an important role in daily commutes in Brazilian cities as population grows in urban areas. However, high volumes of pedestrians near those systems may result in critical safety issues. Recent studies on road safety improvements have sought for evidence on the relationship between built environment - land use patterns; urban design; and transportation systems - and traffic safety. Nevertheless, the relationship between traffic safety at bus priority systems and the built environment is still incipient. According to studies, the most critical safety issues related to public transport are the stations for boarding and alighting. Thus, this thesis aims to verify the relationship between built environment and incidence and severity of traffic crashes in the surroundings of bus priority systems. To do so, we applied Negative Binomial regression models (NB) for the frequency analysis, and the Ordered Logit (OL) and Multinomial Logit (MNL) models for severity analysis. NB models resulted in two significant variables for traffic crashes in general and three variables for pedestrian crashes. The severity model resulted in 19 significant variables overall crashes and eight significant variables for pedestrian crashes. Variables related to the involvement of motorcycles, automobiles, intersections and mixed land use were significant in majority of model estimations. The results allowed to evaluate the goodness of fit between ordered and unordered models. MNL had a slightly better adjustments compared to OL. Goodness of fit, however, should not be the only criterion for selecting a model to assess crash severity.

The basic objective in bulk electrical system planning is to determine the necessary generating facilities required to ensure an adequate and economic supply of electrical energy and the development of an adequate transmission network to transport the generated energy to the customers. Quantitative adequacy assessment is a basic task in achieving this objective. An important requirement in this task is the ability to forecast the system load requirements at specific times in the future. These forecasts must also recognize the inherent uncertainty in predicting the future load demands.<p> The primary focus of the research described in this thesis is to examine the effects and implications of load forecast uncertainty on the load point and system adequacy indices of a composite generation and transmission system. This thesis considers two techniques to incorporate the inherent uncertainty associated with future load forecasts in the adequacy assessment of bulk electrical systems. Base case and factor analyses are performed on a number of power system configurations to identify and address the relative contributions to the load point and system indices due to load forecast uncertainty. A transmission reinforcement option and a number of generation system expansion options are presented to examine the system reliability response due to load forecast uncertainty.<p> The actual magnitudes of the changes due to load forecast uncertainty in the load bus and system risk indices and in the percentage change values are different for each generation expansion scenario. The topology and parameters of the system are different in each of the studied power system configurations. The effect of load forecast uncertainty on the system and load point adequacy can be quantified and utilized in the decision-making process associated with system generation and transmission planning. Load forecast uncertainty has important impacts on the system and load point indices that can only be appreciated by conducting comprehensive bulk system adequacy assessment. The actual effects are a complicated function of the system topology and parameters, and the system load curtailment philosophy.

The basic objective in bulk electrical system planning is to determine the necessary generating facilities required to ensure an adequate and economic supply of electrical energy and the development of an adequate transmission network to transport the generated energy to the customers. Quantitative adequacy assessment is a basic task in achieving this objective. An important requirement in this task is the ability to forecast the system load requirements at specific times in the future. These forecasts must also recognize the inherent uncertainty in predicting the future load demands.<p> The primary focus of the research described in this thesis is to examine the effects and implications of load forecast uncertainty on the load point and system adequacy indices of a composite generation and transmission system. This thesis considers two techniques to incorporate the inherent uncertainty associated with future load forecasts in the adequacy assessment of bulk electrical systems. Base case and factor analyses are performed on a number of power system configurations to identify and address the relative contributions to the load point and system indices due to load forecast uncertainty. A transmission reinforcement option and a number of generation system expansion options are presented to examine the system reliability response due to load forecast uncertainty.<p> The actual magnitudes of the changes due to load forecast uncertainty in the load bus and system risk indices and in the percentage change values are different for each generation expansion scenario. The topology and parameters of the system are different in each of the studied power system configurations. The effect of load forecast uncertainty on the system and load point adequacy can be quantified and utilized in the decision-making process associated with system generation and transmission planning. Load forecast uncertainty has important impacts on the system and load point indices that can only be appreciated by conducting comprehensive bulk system adequacy assessment. The actual effects are a complicated function of the system topology and parameters, and the system load curtailment philosophy.

Com o crescimento da população em áreas urbanas, o transporte coletivo assume um importante papel nos deslocamentos diários nas cidades brasileiras. No entanto, o grande volume de pessoas no entorno desses sistemas podem resultar em pontos críticos de segurança viária. Recentemente, as pesquisas sobre melhorias na segurança viária estão se direcionando para a investigação da relação entre o ambiente construído - isto é, padrões de uso do solo; desenho urbano; e sistemas de transporte - e acidentalidade. Porém, a relação entre os sistemas de transporte coletivo por ônibus e o ambiente construído ainda é pouco explorada. O ponto mais crítico em segurança identificado na literatura em sistemas de transporte coletivo são as estações de embarque e desembarque. Assim, esta dissertação tem como objetivo verificar a existência de relação entre elementos do ambiente construído com a ocorrência e severidade de acidentes viários no entorno de pontos de parada em sistemas prioritários para ônibus. Para isso, aplicou-se os modelos de regressão Binomial Negativo (NB), na análise de frequência de acidentes, e os modelos Logit Ordenado (OL) e Logit Multinomial (MNL), para a análise de severidade. No modelo de frequência de acidentes totais, identificou-se duas variáveis significativas e, no modelo estimado para atropelamentos, três variáveis. O modelo de severidade resultou em 19 variáveis significativas para acidentes totais e oito variáveis significativas para atropelamentos. As variáveis referentes ao envolvimento de motocicletas, automóveis, presença de interseção e uso diversificado do solo foram as mais recorrentes. O estudo possibilitou também avaliar as diferenças e vantagens entre os modelos ordenados e os não-ordenados. O modelo Logit Multinomial teve ajustes levemente melhores do que o Logit Ordenado. Ressalta-se, entretanto, que o ajuste do modelo não deve ser o único critério a se considerar na escolha de modelos para o estudo de severidade de acidentes. / Public transport has played an important role in daily commutes in Brazilian cities as population grows in urban areas. However, high volumes of pedestrians near those systems may result in critical safety issues. Recent studies on road safety improvements have sought for evidence on the relationship between built environment - land use patterns; urban design; and transportation systems - and traffic safety. Nevertheless, the relationship between traffic safety at bus priority systems and the built environment is still incipient. According to studies, the most critical safety issues related to public transport are the stations for boarding and alighting. Thus, this thesis aims to verify the relationship between built environment and incidence and severity of traffic crashes in the surroundings of bus priority systems. To do so, we applied Negative Binomial regression models (NB) for the frequency analysis, and the Ordered Logit (OL) and Multinomial Logit (MNL) models for severity analysis. NB models resulted in two significant variables for traffic crashes in general and three variables for pedestrian crashes. The severity model resulted in 19 significant variables overall crashes and eight significant variables for pedestrian crashes. Variables related to the involvement of motorcycles, automobiles, intersections and mixed land use were significant in majority of model estimations. The results allowed to evaluate the goodness of fit between ordered and unordered models. MNL had a slightly better adjustments compared to OL. Goodness of fit, however, should not be the only criterion for selecting a model to assess crash severity.

Com o crescimento da população em áreas urbanas, o transporte coletivo assume um importante papel nos deslocamentos diários nas cidades brasileiras. No entanto, o grande volume de pessoas no entorno desses sistemas podem resultar em pontos críticos de segurança viária. Recentemente, as pesquisas sobre melhorias na segurança viária estão se direcionando para a investigação da relação entre o ambiente construído - isto é, padrões de uso do solo; desenho urbano; e sistemas de transporte - e acidentalidade. Porém, a relação entre os sistemas de transporte coletivo por ônibus e o ambiente construído ainda é pouco explorada. O ponto mais crítico em segurança identificado na literatura em sistemas de transporte coletivo são as estações de embarque e desembarque. Assim, esta dissertação tem como objetivo verificar a existência de relação entre elementos do ambiente construído com a ocorrência e severidade de acidentes viários no entorno de pontos de parada em sistemas prioritários para ônibus. Para isso, aplicou-se os modelos de regressão Binomial Negativo (NB), na análise de frequência de acidentes, e os modelos Logit Ordenado (OL) e Logit Multinomial (MNL), para a análise de severidade. No modelo de frequência de acidentes totais, identificou-se duas variáveis significativas e, no modelo estimado para atropelamentos, três variáveis. O modelo de severidade resultou em 19 variáveis significativas para acidentes totais e oito variáveis significativas para atropelamentos. As variáveis referentes ao envolvimento de motocicletas, automóveis, presença de interseção e uso diversificado do solo foram as mais recorrentes. O estudo possibilitou também avaliar as diferenças e vantagens entre os modelos ordenados e os não-ordenados. O modelo Logit Multinomial teve ajustes levemente melhores do que o Logit Ordenado. Ressalta-se, entretanto, que o ajuste do modelo não deve ser o único critério a se considerar na escolha de modelos para o estudo de severidade de acidentes. / Public transport has played an important role in daily commutes in Brazilian cities as population grows in urban areas. However, high volumes of pedestrians near those systems may result in critical safety issues. Recent studies on road safety improvements have sought for evidence on the relationship between built environment - land use patterns; urban design; and transportation systems - and traffic safety. Nevertheless, the relationship between traffic safety at bus priority systems and the built environment is still incipient. According to studies, the most critical safety issues related to public transport are the stations for boarding and alighting. Thus, this thesis aims to verify the relationship between built environment and incidence and severity of traffic crashes in the surroundings of bus priority systems. To do so, we applied Negative Binomial regression models (NB) for the frequency analysis, and the Ordered Logit (OL) and Multinomial Logit (MNL) models for severity analysis. NB models resulted in two significant variables for traffic crashes in general and three variables for pedestrian crashes. The severity model resulted in 19 significant variables overall crashes and eight significant variables for pedestrian crashes. Variables related to the involvement of motorcycles, automobiles, intersections and mixed land use were significant in majority of model estimations. The results allowed to evaluate the goodness of fit between ordered and unordered models. MNL had a slightly better adjustments compared to OL. Goodness of fit, however, should not be the only criterion for selecting a model to assess crash severity.

Traffic signals are very cost effective tools for urban traffic management in urban areas. The number of intersections in Sweden controlled by traffic signals has increased since the seventies, but efforts to study the traffic performance of the employed strategies are still lacking. The LHOVRA technique is the predominant isolated traffic signal control strategy in Sweden. Past-end green was originally incorporated as part of LHOVRA (the “O” function) and was intended to reduce the number of vehicles in the dilemma zone. Coordinated signal control in Sweden is often fixed-time with local vehicle actuated signal timing adjustments and bus priority. This research study was undertaken to increase the knowledge of the traffic performance impacts of these strategies. The aim was to evaluate the following control strategies using Stockholm as a case study: 1. The LHOVRA technique with a focus on the “O” function; 2. Fixed time coordination (FTC); 3. Fixed time coordination with local signal timing adjustment (FTC-LTA); 4. FTC-LTA as above + active bus priority (PRIBUSS); 5. Self-optimizing control (SPOT). Field measurements were used for study of driver behavior and traffic impacts as well as for collecting input data needs for simulation. The results from low speed approaches showed a higher proportion of stopped vehicles after receiving green extension. Moving the detectors closer to the stop line, and/or making the detectors speed dependent were suggested as measures to solve these problems. The VISSIM simulation model calibrated and validated with empirical data was used to study traffic performance and safety impacts of the LHOVRA technique as well as to test the suggested improvements. The simulation experiment results from these design changes were shown to reduce accident risk with little or no loss of traffic performance. TRANSYT was used to produce optimized fixed signal timings for coordinated intersections. HUTSIM simulations showed that local signal timing adjustment by means of past-end green was beneficial when applied to coordinated traffic signal control in the study area. Both delays and stops were reduced, although not for the main, critical intersection which operated close to capacity. To study the impacts of strategies for coordinated signal control with bus priority, extensive field data collection was undertaken during separate time periods with these strategies in the same area using mobile and stationary techniques. A method to calculate the approach delay was developed based on the observed number of queuing vehicles at the start and end of green. Compared to FTC-LTA, the study showed that PRIBUSS reduced bus travel time. SPOT reduced both bus and vehicle travel time. Future research efforts for the development of signal control strategies and their implementation in Sweden should be focused on strategies with self-optimization functionality. / QC 20100408