Thesis (Ph.D.)--University of California, Davis, 2007. / Text document in PDF format. Title from PDF title page (viewed on August 30, 2009). "Received by ITS-Davis: July 2007"--Publication detail webpage. Includes bibliographical references (p. 190-195).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1983. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 74-76).

A confiabilidade e a variabilidade do tempo de viagem são importantes fatores na escolha modal dos passageiros em viagens urbanas. Cada vez mais os sistemas de transporte têm buscado, além da redução do tempo médio de viagem, garantir ao usuário maior precisão na previsão do tempo total gasto entre sua origem e seu destino, incluindo aí o tempo de espera, o tempo de viagem e, em alguns casos, o tempo de transferência. Com o incremento do uso do automóvel nas cidades e, consequentemente, o aumento nos índices de congestionamento, a solução adotada pelos planejadores tem sido a dedicação de faixas exclusivas para sistemas de transporte coletivo. É então que, a partir da experiência dos sistemas sobre trilhos aliada à flexibilidade permitida pelos sistemas sobre pneus, surgem os sistemas Bus Rapid Transit (BRT). Esta dissertação contempla a análise da variabilidade do tempo de viagem em sistemas de faixas de prioridade para ônibus a partir do estudo de caso de três sistemas implantados em cidades brasileiras. Através da análise de dispersão dos tempos verificados para os dias úteis de uma semana padrão de operação, é avaliada a variabilidade por faixa horária em cada corredor abordado no estudo de caso. Os resultados apontam para um desvio-padrão por faixa horária entre 0,7% e 14,8% em relação ao tempo médio de viagem nos corredores analisados. A abordagem da variabilidade em corredores de faixas preferenciais para ônibus através do estudo de caso de três corredores Bus Rapid Service (BRS) apontou um coeficiente de variação entre 16,9% e 25,2%. Os resultados da análise comparativa apontam um desempenho superior dos sistemas BRT em relação a corredores BRS no tocante à confiabilidade do tempo de viagem em sistemas de ônibus. / Reliability and travel time variability are key factors in modal choices for urban travel. Apart from reducing the average travel time, transport systems have tried to ensure that travelers could have a sharper prediction in time to be spent commuting including waiting time, journey time and in some cases the transference time. As cars have become more used in big cities, and thus increasing traffic jam, the solution found by planners have been lanes only for public transportation. Mixing the experience of rail systems with the flexibility allowed by road ones, Bus Rapid Transit (BRT) were created. This study approaches the analysis of the travel time variability in priority systems for bus type BRT from the case study of three systems implemented in Brazilian cities. Through analysis of dispersion times observed for working days of a week standard operation, the variability per hour found in each corridor covered in the case study is evaluated. The results show an standard deviation by time band of 0.7% - 14.8% over the average travel time. The approach of the variability in corridors with preferential bus lanes through the case study of three corridors Bus Rapid Service (BRS) showed a coefficient of variation between 16.9% and 25.2%. Results indicate superior performance of BRT systems in relation to BRS corridors regarding the reliability of travel time by bus systems.

A confiabilidade e a variabilidade do tempo de viagem são importantes fatores na escolha modal dos passageiros em viagens urbanas. Cada vez mais os sistemas de transporte têm buscado, além da redução do tempo médio de viagem, garantir ao usuário maior precisão na previsão do tempo total gasto entre sua origem e seu destino, incluindo aí o tempo de espera, o tempo de viagem e, em alguns casos, o tempo de transferência. Com o incremento do uso do automóvel nas cidades e, consequentemente, o aumento nos índices de congestionamento, a solução adotada pelos planejadores tem sido a dedicação de faixas exclusivas para sistemas de transporte coletivo. É então que, a partir da experiência dos sistemas sobre trilhos aliada à flexibilidade permitida pelos sistemas sobre pneus, surgem os sistemas Bus Rapid Transit (BRT). Esta dissertação contempla a análise da variabilidade do tempo de viagem em sistemas de faixas de prioridade para ônibus a partir do estudo de caso de três sistemas implantados em cidades brasileiras. Através da análise de dispersão dos tempos verificados para os dias úteis de uma semana padrão de operação, é avaliada a variabilidade por faixa horária em cada corredor abordado no estudo de caso. Os resultados apontam para um desvio-padrão por faixa horária entre 0,7% e 14,8% em relação ao tempo médio de viagem nos corredores analisados. A abordagem da variabilidade em corredores de faixas preferenciais para ônibus através do estudo de caso de três corredores Bus Rapid Service (BRS) apontou um coeficiente de variação entre 16,9% e 25,2%. Os resultados da análise comparativa apontam um desempenho superior dos sistemas BRT em relação a corredores BRS no tocante à confiabilidade do tempo de viagem em sistemas de ônibus. / Reliability and travel time variability are key factors in modal choices for urban travel. Apart from reducing the average travel time, transport systems have tried to ensure that travelers could have a sharper prediction in time to be spent commuting including waiting time, journey time and in some cases the transference time. As cars have become more used in big cities, and thus increasing traffic jam, the solution found by planners have been lanes only for public transportation. Mixing the experience of rail systems with the flexibility allowed by road ones, Bus Rapid Transit (BRT) were created. This study approaches the analysis of the travel time variability in priority systems for bus type BRT from the case study of three systems implemented in Brazilian cities. Through analysis of dispersion times observed for working days of a week standard operation, the variability per hour found in each corridor covered in the case study is evaluated. The results show an standard deviation by time band of 0.7% - 14.8% over the average travel time. The approach of the variability in corridors with preferential bus lanes through the case study of three corridors Bus Rapid Service (BRS) showed a coefficient of variation between 16.9% and 25.2%. Results indicate superior performance of BRT systems in relation to BRS corridors regarding the reliability of travel time by bus systems.

A confiabilidade e a variabilidade do tempo de viagem são importantes fatores na escolha modal dos passageiros em viagens urbanas. Cada vez mais os sistemas de transporte têm buscado, além da redução do tempo médio de viagem, garantir ao usuário maior precisão na previsão do tempo total gasto entre sua origem e seu destino, incluindo aí o tempo de espera, o tempo de viagem e, em alguns casos, o tempo de transferência. Com o incremento do uso do automóvel nas cidades e, consequentemente, o aumento nos índices de congestionamento, a solução adotada pelos planejadores tem sido a dedicação de faixas exclusivas para sistemas de transporte coletivo. É então que, a partir da experiência dos sistemas sobre trilhos aliada à flexibilidade permitida pelos sistemas sobre pneus, surgem os sistemas Bus Rapid Transit (BRT). Esta dissertação contempla a análise da variabilidade do tempo de viagem em sistemas de faixas de prioridade para ônibus a partir do estudo de caso de três sistemas implantados em cidades brasileiras. Através da análise de dispersão dos tempos verificados para os dias úteis de uma semana padrão de operação, é avaliada a variabilidade por faixa horária em cada corredor abordado no estudo de caso. Os resultados apontam para um desvio-padrão por faixa horária entre 0,7% e 14,8% em relação ao tempo médio de viagem nos corredores analisados. A abordagem da variabilidade em corredores de faixas preferenciais para ônibus através do estudo de caso de três corredores Bus Rapid Service (BRS) apontou um coeficiente de variação entre 16,9% e 25,2%. Os resultados da análise comparativa apontam um desempenho superior dos sistemas BRT em relação a corredores BRS no tocante à confiabilidade do tempo de viagem em sistemas de ônibus. / Reliability and travel time variability are key factors in modal choices for urban travel. Apart from reducing the average travel time, transport systems have tried to ensure that travelers could have a sharper prediction in time to be spent commuting including waiting time, journey time and in some cases the transference time. As cars have become more used in big cities, and thus increasing traffic jam, the solution found by planners have been lanes only for public transportation. Mixing the experience of rail systems with the flexibility allowed by road ones, Bus Rapid Transit (BRT) were created. This study approaches the analysis of the travel time variability in priority systems for bus type BRT from the case study of three systems implemented in Brazilian cities. Through analysis of dispersion times observed for working days of a week standard operation, the variability per hour found in each corridor covered in the case study is evaluated. The results show an standard deviation by time band of 0.7% - 14.8% over the average travel time. The approach of the variability in corridors with preferential bus lanes through the case study of three corridors Bus Rapid Service (BRS) showed a coefficient of variation between 16.9% and 25.2%. Results indicate superior performance of BRT systems in relation to BRS corridors regarding the reliability of travel time by bus systems.

Arterial performance measurement is an essential tool for both researchers and practitioners, guiding decisions on traffic management, future improvements, and public information. Link travel time and intersection control delay are two primary performance measures that are used to evaluate arterial level of service. Despite recent technological advancements, collecting travel time and intersection delay data can be a time-consuming and complicated process. Limited budgets, numerous available technologies, a rapidly changing field, and other challenges make performance measurement and comparison of data sources difficult. Three common data collection sources (probe vehicles, Bluetooth media access control readers, and manual queue length counts) are often used for performance measurement and validation of new data methods. Comparing these and other data sources is important as agencies and researchers collect arterial performance data. This study provides a methodology for comparing data sources, using statistical tests and linear correlation to compare methods and identify strengths and weaknesses. Additionally, this study examines data normality as an issue that is seldom considered, yet can affect the performance of statistical tests. These comparisons can provide insight into the selection of a particular data source for use in the field or for research. Data collected along Grant Road in Tucson, Arizona, was used as a case study to evaluate the methodology and the data sources. For evaluating travel time, GPS probe vehicle and Bluetooth sources produced similar results. Bluetooth can provide a greater volume of data more easily in addition to samples large enough for more rigorous statistical evaluation, but probe vehicles are more versatile and provide higher resolution data. For evaluating intersection delay, probe vehicle and queue count methods did not always produce similar results.

South African metropolitan areas are experiencing rapid growth and require an increase in network infrastructure. Increased congestion negatively impacts both public and freight transport costs. The concept of City Logistics is concerned with the mobility of cities, and entails the process of optimizing urban logistics activities by concerning the social, environmental, economic, financial, and energy impacts of urban freight movement. In a costcompetitive environment, freight transporters often use sophisticated vehicle routing and scheduling applications to improve fleet utilization and reduce the cost of meeting customer demands. In this thesis, the candidate builds on the observation that vehicle routing and scheduling algorithms are inherent problem specific, with no single algorithm providing a dominant solution to all problem environments. Commercial applications mostly deploy a single algorithm in a multitude of environments which would often be better serviced by various different algorithms. This thesis algorithmically implements the ability of human decision makers to choose an appropriate solution algorithm when solving scheduling problems. The intent of the routing agent is to classify the problem as representative of a traditional problem set, based on its characteristics, and then to solve the problem with the most appropriate solution algorithm known for the traditional problem set. A not-so-artificially-intelligent-vehicle-routing-agent™ is proposed and developed in this thesis. To be considered intelligent, an agent is firstly required to be able to recognize its environment. Fuzzy c-means clustering is employed to analyze the geographic dispersion of the customers (nodes) from an unknown routing problem to determine to which traditional problem set it relates best. Cluster validation is used to classify the routing problem into a traditional problem set. Once the routing environment is classified, the agent selects an appropriate metaheuristic to solve the complex variant of the Vehicle Routing Problem. Multiple soft time windows, a heterogeneous fleet, and multiple scheduling are addressed in the presence of time-dependent travel times. A new initial solution heuristic is proposed that exploits the inherent configuration of customer service times through a concept referred to as time window compatibility. A high-quality initial solution is subsequently improved by the Tabu Search metaheuristic through both an adaptive memory, and a self-selection structure. As an alternative to Tabu Search, a Genetic Algorithm is developed in this thesis. Two new crossover mechanisms are proposed that outperform a number of existing crossover mechanisms. The first proposed mechanism successfully uses the concept of time window compatibility, while the second builds on an idea used from a different sweeping-arc heuristic. A neural network is employed to assist the intelligent routing agent to choose, based on its knowledge base, between the two metaheuristic algorithms available to solve the unknown problem at hand. The routing agent then not only solves the complex variant of the problem, but adapts to the problem environment by evaluating its decisions, and updating, or reaffirming its knowledge base to ensure improved decisions are made in future. / Thesis (PhD (Industrial Engineering))--University of Pretoria, 2007. / Industrial and Systems Engineering / PhD / unrestricted

This thesis investigates how a closure of a maternity ward affects the moves intoand out of a municipality. The policy focus of a centralization of maternal care in Sweden may bring unseen consequences that matter for society in a larger sense than only births. By treating closeness to a maternity ward as a positive amenity for a municipality, these closures introduce an exogenous variation that is used to estimate how moves change over time. With the lack of data availability, utilizing Sweden’s administrative areas, the lack of data over amenities as well as other factors such as employment possibilities are compensated for, revealing the possibility of using similar areas as potential substitutes for amenities. The results indicate that closures are likely to introduce a lower mobility for the regions as both fewer moves in and fewer moves out are revealed in the estimates. The results are strongly significant, a one minute increase of travel time would be associated with a decrease of around 3 moves in and 2.7 moves out. These results are mostly robust, and findings suggest north and south of Sweden are fundamentally different.

Weather conditions may impact traffic flow in different ways. Both the human decisions regarding the trip (route, mode, time) and the trip itself can significantly vary. Driver’s behavior may be affected by weather resulting in, among others, deterioration of the network ’s travel times and speeds. Therefore to study and analyse travel times under different weather conditions, represents an important instrument to support Intelligent Transport Systems (ITS). With the correct knowledge and information, travellers would be able to plan their trips in a cost-efficient way, while traffic managers could take advantages of these predictions to deploy control strategies (e.g. weather-responsive signal timing plans). In this project Automatic Number Plate Recognition (ANPR) data from summer 2012 to summer 2013 from three different arterial routes in Stockholm city is used in order to analyze travel times, at a link level, under different weather conditions. To determine to what extent weather variables such as rain, snowfall, temperature and visibility impact the speeds in the network, weather data is integrated with traffic data (ANPR) and analyzed through linear regression models. Results show that there is in fact a negative effect on speed but also on speed’s variability. This knowledge can be useful for trip planning and for traffic management under different weather conditions.

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