Transportation engineers and planners worldwide are faced with the challenge of improving transit services in urban areas using low cost means. Transit signal priority is considered to be an effective way to improve transit service reliability and efficiency. In light of the interest in testing and deploying transit signal priority on a major arterial in Northern Virginia, this research focuses on the impacts of transit signal priority in the U.S.1 corridor in Fairfax County in terms of benefits to transit and impacts on other traffic. Using a simulation tool, VISSIM, these impacts were assessed considering a ten second green extension priority strategy. The results of the simulation analysis indicated that the Fairfax Connector buses benefit from the green extension strategy with little to no impact on the other non-transit traffic. Overall, improvements of 3.61% were found for bus service reliability and 2.64% for bus efficiency, while negative impacts were found in the form of increases in queue lengths on side streets by a maximum value of approximately one vehicle. Because this research has provided a foundation for the evaluation of transit signal priority for VDOT and Fairfax County engineers and planners, future research can build upon this effort. Areas identified for future research include the provision of priority for the entire bus route; combination of emergency preemption and transit priority strategies; evaluation of other priority strategies using system- wide priority concepts; and the impacts of priority strategies in monetary terms. / Master of Science

IntelliDrive is an initiative developed by United States Department of Transportation (USDOT) that aims to enable safe, interoperable networked wireless communications among vehicles, the infrastructure, and passengers' personal communications devices. IntelliDrive technology has the ability to provide data that would be helpful in enhancement of the existing traffic management applications. IntelliDrive data has attributes that cannot be measured using traditional surveillance technology and which can be used for the development of new traffic management and traveler information applications. The traffic responsive plan selection (TRPS) mode of operation is used in coordinated traffic network to improve the performance of the system. This mode of operation has the ability to implement the best possible timing plan for the existing traffic conditions by switching between timing plans. The data from IntelliDrive technology can be utilized in the traffic responsive mode to improve the system performance by reducing the overall delay in the system. This paper proposes a system that can be used to integrate the data obtained from the IntelliDrive technology to the traffic responsive mode of operation. The proposed method utilizes the number of stops and delay of the vehicles in an intersection as a basis for the implementation of the best timing plan for the prevailing traffic condition. The study shows that using the IntelliDrive based TRPS results in the selection of the traffic plan that minimizes the delay of the system and thus results in better system performance compared to the traditional traffic responsive mechanism. / Master of Science

Traffic simulation is a powerful tool that provides transportation engineers with the ability to test the feasibility and performance of a system before it is implemented and also helps in optimizing the proposed system. Over the past twenty years significant amount of work has been conducted on improving the quality and accuracy of transportation simulation models. Much of this work has been concentrated on microscopic simulation models because they provide traffic engineers greater opportunity to examine the inherently complex, stochastic, and dynamic nature of transportation systems when compared to traditional macroscopic models. In order to test the performance of some of the simulation models, a study is conducted on freeway weaving sections, which are considered to be one of the most complex regions to be modeled and analyzed. The intent of the research is to evaluate TRANSIMS, CORSIM, VISSIM and INTEGRATION and compare them with Highway Capacity Manual, which adopts a traditional methodology for carrying out the operational analysis of a highway system. The statistics collected for the simulation runs include weaving speeds, non-weaving speeds and density of the weaving section. / Master of Science

Os simuladores de tráfego são programas computacionais que, através de diversos modelos, tentam simular o tráfego, o comportamento dos motoristas, o desempenho dos veículos, entre outros aspectos que envolvem uma rede viária. Estes modelos precisam ser calibrados para representar as condições de um determinado local. O objetivo da pesquisa foi propor um método de calibração de um microssimulador de tráfego através de dados coletados por estações de monitoramento. O estudo de caso foi realizado através do simulador VISSIM para um trecho do Rodoanel Mário Covas (SP-021), utilizando um algoritmo genético (AG). A calibração envolveu, além dos parâmetros comportamentais dos sub-modelos de car-following e lane-change, o ajuste das distribuições de velocidade desejada dos veículos e um método para simulação do congestionamento. A função fitness do AG foi baseada em três medidas de desempenho: uma que comparava gráficos de fluxo-velocidade simulados e observados e outras duas que comparavam a distribuição do volume de tráfego e o percentual de veículos comerciais por faixa de tráfego. Os resultados mostraram que a medida mais apropriada para a comparação dos gráficos foi a distância de Hausdorff modificada (MHD). A medida MHD também foi fundamental para garantir a ciência do método de simulação de congestionamento de tráfego proposto. O modelo calibrado foi validado usando dados de tráfego coletados em dias diferentes, pela mesma estação de monitoramento. / Traffic simulators are computer programs that, through various models, try to simulate traffic, driver behavior, vehicle performance, and other aspects involved in a road network. These models need calibration to represent local conditions satisfactorily. The objective of the research was to propose a method for the calibration of a traffic microsimulator based on traffic data collected by monitoring stations. To demonstrate the feasibility of the proposed approach, a case study was performed calibrating the simulator VISSIM for a section of Rodoanel Mario Covas (SP-021) using a genetic algorithm (GA). The calibration focused on behavioral parameters for car-following and lane-change submodels, as well as on the desired speed distributions of vehicles and on a method to simulate congestion. The GA fitness function was based on three performance measures: one that compared simulated and observed speed-flow plots, and two that compared the distribution of traffic volume and truck volumes across traffic lanes, respectively. The results showed that the most appropriate measure for comparison of the graphs was the modified Hausdor distance (MHD). MHD was also important to ensure the efficiency of the method used to simulate traffic congestion. The calibrated model was validate using traffic data collected on different days, by the same monitoring station.

Os simuladores de tráfego são programas computacionais que, através de diversos modelos, tentam simular o tráfego, o comportamento dos motoristas, o desempenho dos veículos, entre outros aspectos que envolvem uma rede viária. Estes modelos precisam ser calibrados para representar as condições de um determinado local. O objetivo da pesquisa foi propor um método de calibração de um microssimulador de tráfego através de dados coletados por estações de monitoramento. O estudo de caso foi realizado através do simulador VISSIM para um trecho do Rodoanel Mário Covas (SP-021), utilizando um algoritmo genético (AG). A calibração envolveu, além dos parâmetros comportamentais dos sub-modelos de car-following e lane-change, o ajuste das distribuições de velocidade desejada dos veículos e um método para simulação do congestionamento. A função fitness do AG foi baseada em três medidas de desempenho: uma que comparava gráficos de fluxo-velocidade simulados e observados e outras duas que comparavam a distribuição do volume de tráfego e o percentual de veículos comerciais por faixa de tráfego. Os resultados mostraram que a medida mais apropriada para a comparação dos gráficos foi a distância de Hausdorff modificada (MHD). A medida MHD também foi fundamental para garantir a ciência do método de simulação de congestionamento de tráfego proposto. O modelo calibrado foi validado usando dados de tráfego coletados em dias diferentes, pela mesma estação de monitoramento. / Traffic simulators are computer programs that, through various models, try to simulate traffic, driver behavior, vehicle performance, and other aspects involved in a road network. These models need calibration to represent local conditions satisfactorily. The objective of the research was to propose a method for the calibration of a traffic microsimulator based on traffic data collected by monitoring stations. To demonstrate the feasibility of the proposed approach, a case study was performed calibrating the simulator VISSIM for a section of Rodoanel Mario Covas (SP-021) using a genetic algorithm (GA). The calibration focused on behavioral parameters for car-following and lane-change submodels, as well as on the desired speed distributions of vehicles and on a method to simulate congestion. The GA fitness function was based on three performance measures: one that compared simulated and observed speed-flow plots, and two that compared the distribution of traffic volume and truck volumes across traffic lanes, respectively. The results showed that the most appropriate measure for comparison of the graphs was the modified Hausdor distance (MHD). MHD was also important to ensure the efficiency of the method used to simulate traffic congestion. The calibrated model was validate using traffic data collected on different days, by the same monitoring station.

In Visby, cruise calls have become less frequent over the years and to prevent this development it has been decided to build a cruise port located south of Visby harbor. To reach Visby the cruise passengers need to pass through the harbor and all its crossings. However, in Visby harbor the ferries to the mainland are already causing traffic jams during peak season and without a functioning transport solution the cruise passengers will probably cause even bigger problems. In order to encourage a sustainable tourism a traffic solution for the harbor needs to be presented. The aim of this study is to evaluate how the new cruise port will affect the traffic situation in Gotland, both local and regional. A qualitative study has been carried out to gather information and opinions from local actors in Gotland, regarding traffic and tourism. Based on this qualitative study and a method developed by the Swedish transportadministration, four different transport solutions have been evaluated. One shuttlebus solution and three different walkways. These solutions have been simulated in the software Vissim in order to evaluate the efficiency for each solution, and in Enviver to calculate the emissions they cause. The study shows that the walkway that does not affect traffic in the harbor is the solution that is most efficient and has lowest emissions, but it also demands large investments. The shuttlebus solution was also efficient but with higher emissions and it is dependent on buses and drivers to be available.

A malha rodoviária brasileira é constituída predominantemente de rodovias de pista simples e boa parte delas encontra-se em regiões montanhosas. Rodovias de pista simples em regiões montanhosas possuem dificuldades de modelagem, porque as rampas elevadas e os raios de curvatura pequenos possuem impacto significativo no desempenho do tráfego. Adicionalmente, existem poucos estudos de simulação de tráfego de veículos em rodovias de pista simples, sobretudo em regiões montanhosas. Sendo assim, a combinação de rodovias de pista simples com região montanhosa é ainda mais restrita para codificação dessas redes em microssimuladores de tráfego. Dados de geometria de rodovias são comumente obtidos por meio de plataformas como o Google Earth, contudo sua precisão pode ser insuficiente para uma boa representação em regiões montanhosas, devido à influência significativa dos perfis planialtimétricos no desempenho do tráfego em rodovias de pistas simples. O presente trabalho desenvolveu uma metodologia para a codificação de rodovias de pista simples em região montanhosa. Esta metodologia foi aplicada em um estudo de simulação de tráfego através do microssimulador de tráfego VISSIM. O trecho de estudo de caso corresponde à 16 km de extensão da ERS-115 entre as cidades de Três Coroas e Gramado na Serra Gaúcha. A partir de dois bancos de dados (Google Earth e levantamento veicular a Laser), foram desenvolvidos três modelos: (i) modelo baseado nos dados originais do Google (Google original), (ii) modelo com perfil altimétrico suavizado (LOESS) e (iii) modelo com perfil planialtimétrico baseado em levantamento de campo a Laser (Laser). A comparação do perfil altimétrico dos três modelos revelou diferenças significativas entre o modelo do Google original em relação aos demais. O perfil altimétrico decorrente dos dados originais do Google Earth apresentou grandes declividades, na prática, incompatíveis com a classe da rodovia. O método proposto de suavização (LOESS) resultou em um modelo bem mais próximo do perfil real da rodovia, representado pelo modelo construído a partir do levantamento a laser. Com o objetivo de avaliar o desempenho através da simulação de tráfego nos 3 modelos foram executados 11 cenários de simulação. Os cenários envolveram 2 níveis de demanda: demanda baixa, compatível com condições de fluxo livre e uma demanda representativa das condições típicas de tráfego verificadas no trecho. Em relação à demanda em fluxo livre, veículos nos modelos Laser e LOESS apresentaram velocidades similares ao longo do estaqueamento, enquanto que o modelo Google original revelou diferenças significativas de velocidades. A análise do desempenho do tráfego nos cenários de demanda típica foi baseada nos tempos de viagem. Cenários nesta análise envolveram a segmentação da rodovia em trechos homogêneos e variações na proporção de veículos por sentido (split direcional). A comparação entre os tempos de viagem dos modelos LOESS e Laser resultou em R²=0,99, enquanto que R² obtidos entre os modelos Google original e Laser variaram no intervalo de 0,04 a 0,99. Os resultados obtidos apontam a importância da metodologia desenvolvida pelo presente trabalho na modelagem de rodovias de pista simples, sobretudo em região montanhosa. / The Brazilian road network consists predominantly of two-lane highways and great part of them are in mountainous regions. Two-lane highways in mountainous regions have modeling difficulties because high slopes and small bend radii have a significant impact on traffic performance. Additionally, there are few simulation studies of vehicle traffic on two-lane highways, especially in mountainous regions. Thus, the combination of two-lane highways and mountainous region is even more restricted for coding these networks into traffic microsimulators. Road geometry data are commonly obtained through platforms such as Google Earth, but their accuracy may be insufficient for good representation in mountainous regions due to significant influence of planialtimetric profiles on traffic performance on two-lane highways. The present work developed a methodology for the codification of two-lane highways in mountainous region. This methodology was applied in a simulation study of traffic through the VISSIM traffic microsymulator. The case study section corresponds to the 16 km extension of the ERS-115 between the cities of Três Coroas and Gramado in the Serra Gaúcha. From two databases (Google Earth and Laser Vehicle Survey), three models were developed: (i) model based on original Google data (Google original), (ii) model with smoothed altimetric profile (LOESS) and (iii) model with planialtimetric profile based on laser field survey (Laser). The comparison of altimetric profiles of the three models revealed significant differences between the Google original model in relation to the others. The altimetric profile derived from the original data of Google Earth presented great slopes, in practice, incompatible with the highway class. The proposed smoothing method (LOESS) resulted in a model that is closer to the actual road profile, represented by the model constructed from the laser survey. In order to evaluate the performance through the simulation of traffic in the three models, 11 simulation scenarios were executed. The scenarios involved two levels of demand: low demand, compatible with free flow conditions and a representative demand of the typical traffic conditions verified in the road segment. Regarding the free-flow demand, vehicles in Laser and LOESS models presented similar speeds along the road, while the Google original model revealed significant differences in speeds. The analysis of traffic performance in typical demand scenarios was based on travel times. Scenarios in this analysis involved the segmentation of the highway in homogeneous segments and variations in the proportion of vehicles by direction (directional split). The comparison of travel times of the LOESS and Laser models resulted in R² = 0.99, while R² obtained between the Google original and Laser models varied in the range of 0.04 to 0.99. The results obtained point out the importance of the methodology developed by the present work in the modeling of two-lane highways, especially in the mountainous region.

La presente tesis se basa en el análisis del flujo vehicular, presente en el óvalo La Curva, ubicada en el distrito de Chorrillos, Departamento de Lima-Perú. El proyecto evalúa las condiciones de servicio, diseño del óvalo y el tráfico vehicular. Esta evaluación es realizada mediante un modelo microscópico que es simulado en el software Vissim 9.0. La construcción del modelo consiste en 4 fases. La primera, trata del análisis previo, que abarca desde la recolección de datos hasta el procesamiento en gabinete. Por un lado, la toma de medidas geométricas se realizó en un día de menor volumen vehicular. Por otro lado, el aforo vehicular y peatonal se realizó en un día típico. La segunda fase consiste en el modelamiento inicial, que busca trasladar el diseño geométrico actual al Vissim para proceder con la microsimulación. Asimismo, se realizaron múltiples corridas hasta lograr la optimización del modelo, previo precalentamiento y calibración del mismo. La tercera fase analiza el diseño propuesto en base a los parámetros de eficiencia vehicular, como son el tiempo de viaje (demoras), la longitud de cola y el nivel de servicio. La propuesta busca optimizar el sistema de semaforización, actualmente existente e inoperativa, y un cambio de nivel en una de las avenidas que concurre mayor cantidad flujo vehicular. En la última fase se busca evaluar y comparar los resultados, tanto de la situación actual como de la alternativa propuesta. Finalmente, los parámetros que presenten mejoras en su servicio serán determinantes para reducir el problema de congestión vehicular. / This thesis is based on the analysis of vehicle flow, present in the La Curva oval, located in the district of Chorrillos, Department of Lima-Peru. The project evaluates service conditions, oval design and vehicular traffic. This evaluation is done through a microscopic model that is simulated in Vissim 9.0 software. The construction of the model consists of 4 phases. The first one deals with the previous analysis, which ranges from data collection to cabinet processing. On the one hand, the geometric measurements were taken on a day with less vehicular volume. On the other hand, vehicular and pedestrian traffic was performed on a typical day. The second phase consists of the initial modeling, which seeks to transfer the current geometric design to the Vissim to proceed with the microsimulation. Likewise, multiple runs were performed until the model was optimized, after preheating and calibrating it. The third phase analyzes the proposed design based on vehicle efficiency parameters, such as travel time (delays), tail length and service level. The proposal seeks to optimize the traffic signaling system, currently existing and inoperative, and a change of level in one of the avenues that has the greatest amount of traffic flow. In the last phase, the aim is to evaluate and compare the results, both of the current situation and of the proposed alternative. Finally, the parameters that present improvements in their service will be decisive to reduce the problem of vehicular congestion. / Tesis

High intensity Activated cross WalK (HAWK), as an innovative pedestrian-activated beacon, has become a hot topic and was introduced in 2009 Manual on Uniform Traffic Control Devices (MUTCD). According to the 2009 MUTCD?HAWK should be installed at least 100 feet from a stop-controlled intersection. This thesis first evaluates the distance between HAWK and stop-controlled intersection recommended by 2009 MUTCD. On the basis of the knowledge of HAWK operation, this thesis applies the Generalized Linear Model (GLM) to model the pedestrian delay at an HAWK location. The HAWK pedestrian delay model includes the major street arrival rate, minor street arrival rate, pedestrian arrival rate and the distance between HAWK and intersection. Four different functional forms are investigated in order to select an appropriate one that could more accurately model pedestrian delay. The minimum green time for vehicles, as an important variable in the HAWK pedestrian delay model and a peculiar element in HAWK operations, is also evaluated with VISSIM simulation based on different vehicle and pedestrian volume combinations. The impact of the HAWK on pedestrian delay is simulated by comparing pedestrian delay in scenarios with and without HAWK. The results indicate that the minimum distance between HAWK and stop-controlled intersection recommended in MUTCD may be inadequate for high demand situations. More distance from HAWK to stop-controlled intersection needs to be considered in order to avoid vehicle spillback to the upstream intersection. Based upon the results of training and validating datasets, it can be indicated that the HAWK pedestrian delay model developed in this study is capable of effectively evaluating the pedestrian delay with a satisfactory accuracy. The study also identifies that a minimum green time for vehicles should be considered in order to reduce the vehicular delay and different minimum green times be provide for vehicles based on different pedestrian volume and vehicle volume combinations. A model of minimum green time for vehicles is then derived from HAWK pedestrian delay model. Finally, the study results indicate that a HAWK installation may increase pedestrian delay for the stop-controlled intersection scenario when vehicle demand is low.

Congestion on the road is identified as a severe threat to nations’ economy. To address this problem, in the past the capacity of existing infrastructure is increased by building new roads. But as history has shown, it is not only an expensive and unsustainable, but also not an efficient way of dealing with this problem. Alternatively, by identifying underutilized links, for example, in the form of parallel routes, the already existing infrastructure can often be used more efficient. This thesis focuses on the development of a framework to simulate re-routing incentives to enable an improved travel corridor performance. Thus, the effects of providing traveler information and tendering mometary incentives on a concidor’s traffic flow are investigated. The aim is to show that by changing the route choice behavior of a certain percentage of the fleet, the overall performance of the existing corridor can be increased. By using the microscopic traffic simulation tool VISSIM in combination with dynamic traffic modeling, numerous scenarios are simulated. By gradually increasing the amount of users who get access to the incentive scheme, the impacts of the penetration get analyzed as well. Based on a network stretch located in California, United States, the simulation model is developed. Using this model, three different scenarios are investigated in detail: a No Incident scenario, a Construction Work scenario and an Accident scenario. Finally, a comprehensive analysis of the simulation results takes place. It mainly focuses on the indicator travel time to discuss the impacts on the corridor performance. Interpreting the achieved simulation results, it can be stated that already small penetration rates have the potential for a significant increase of the corridor performance. To be able to optimize the corridor’s performance, free capacity on detours – especially  at bottlenecks like ramps – has to be available. Nevertheless, in case of high penetration rates, straightforward broadcasting of incentives is not an option.