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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

A BRT Corridor Through Stockholm’s Inner-city : Assessing the Operational Impacts of a BRT Corridor Along Bus Line 4 Using Microscopic Simulation

CARON MALUCELLI, FRANCISCO January 2020 (has links)
Bus Rapid Transit (BRT) corridors and systems have emerged in the past three decades as affordablesolutions of medium capacity public transport services to highly urbanized areas, especially in LatinAmerica and Asia. In Stockholm, trunk bus lines have gained priority over mixed traffic over the yearsthrough exclusive bus lanes, signal priority, and reliability control, for example, but no complete BRTsolution has been implemented yet. Among the inner-city trunk lines, Line 4 is the most demanded witharound 70,000 passengers boarding the service daily. This thesis proposes, then, to assess theoperational impacts that BRT solutions as segregate median lanes, stations with off-board farecollection and platform level boarding and alighting through all bus doors, full signal priority andheadway control strategy, would have in bus Line 4, using a microscopic simulation approach. Twoscenarios were simulated, and the results compared to the existing conditions (Base Scenario).Scenario 1 considered a 5-minute headway service and Scenario 2, 3-minute headways. Overall, theproposed scenarios reduce travel times by 37.6-49.1%, increase average operational speeds (includingdwell times) by 60.4-96.6%, decrease dwell times by 57.9-65.6%, decrease delays by 18.4-36%,decrease vehicle occupancy rates by 3.5-44.9% and improve the Coefficient of Variation of theheadways from 0.83-0.85 in the Base Scenario to 0.1 in Scenario 1 and 0.2 in Scenario 2. As a resultof the reduction in travel times, a BRT service would need 13 buses to operate a 5-minute headwayand 21 buses for a 3-minute headway, against 27 vehicles that are used currently for a 4 to 6-minuteheadway during peak hour.
62

Modelling behavior of cyclists to evaluate bicycle traffic performance

PÉREZ CASTRO, GUILLERMO January 2020 (has links)
Over the past years, bicycles started to gain popularity and more people are now using it as amean of transportation. Nowadays, sustainability trends promote cycling as one of the greenestsolutions for the future in mobility. With this rising demand in the number of bicycle trips, there isa need to design adequate infrastructure fitted to the behavior of cyclists and their traffic patterns.Even though there is plenty information regarding car driving behavior, there is still a lack ofunderstanding in how cyclists behave. Consequently, the behavior of cyclists is often modelled byadjusting parameters from models originally designed for other types of users (e.g. car-followingmodels).The purpose of this degree project is to increase the understanding of the behavior of cyclists byinvestigating the extent to what car-following models can be used to simulate bicycle traffic andwhat effects relevant parameters have on the behavior of simulated cyclists and specific trafficcharacteristics. The main method is microscopic traffic simulation, through the simulation programVissim, of bicycle traffic flow on a two-way separated cycle path in Stockholm, withoutdisturbances from pedestrian and car traffic. In addition, a sensitivity analysis is presented, withthe support of the Elementary Effects method, of behavioral parameters of following, overtaking,lateral position, and the longitudinal gradient of the cycle path, and their effects on speed, lateralposition, and time headway.The sensitivity analysis showed that the minimum lateral distance between cyclists is a keyparameter to model following and overtaking behavior, while the gradient was found to be animportant factor that has a great impact on the bicycle traffic performance. Overall, the resultsindicated that the Vissim implementation of the Wiedemann car-following model is able toreproduce the speed and time headway on flat cycle paths with high flows, with goodapproximation to reality. However, the model failed to represent the effect of gradient, and thelateral position of cyclists could only be achieved with a low level of detail and accuracy.The understanding of the behavior of cyclists is crucial for the design and planning of infrastructurededicated to bicycles, so transport planners can consider the needs of cyclists. This projectcontributes to establish a baseline for bicycle traffic modelling and its adaptation of car-followingmodels to simulate cyclists and bicycle traffic. The awareness of these adaptations will help topromote cycling in order to achieve a more sustainable transport system
63

Enhancing the Existing Microscopic Simulation Modeling Practice for Express Lane Facilities

Machumu, Kelvin S 01 January 2017 (has links)
The implementation of managed lanes (MLs), also known as dynamically priced express lanes, to improve freeway traffic flow and personal throughput is on the rise. Congestion pricing is increasingly becoming a common strategy for congestion management, often requiring microscopic simulation during both planning and operational stages. VISSIM is a recognized microscopic simulation software used for analyzing the performance of managed lanes (MLs). This thesis addressed two important microscopic simulation issues that affect the evaluation results of MLs. One of the microscopic simulation issues that has not yet been addressed by previous studies is the required minimum managed lane routing decision (MLRD) distance upstream of the ingress point of MLs. Decision distance is an optimal upstream distance prior to the ingress at which drivers decide to use MLs and change lanes to orient on a side of MLs ingress. To answer this question, this study used a VISSIM model simulating I-295 proposed MLs in Jacksonville, Florida, United States (U.S), varying the MLRD point at regular intervals from 500 feet to 7,000 feet for different levels of service (LOS) input. Three measures of effectiveness (MOEs) - speed, the number of vehicles changing lanes, and following distance - were used for the analysis. These MOEs were measured in the 500 feet zone prior to the ingress. The results indicate that as the LOS deteriorates, speed decreases, the number of vehicles changing lanes increases, and the following distance decreases. When the LOS is constant, the increase in the MLRD distance from the ingress point was associated with the increase in the speed at the 500 feet zone prior to the ingress, less number of lane changes, and the increase in following vehicle gap. However, the MOEs approached constant values after reaching a certain MLRD distance. LOS D was used to determine the minimum MLRD distance to the ingress of the MLs. The determined minimum MLRD distances were 4,000 and 3,000 feet for 6 and 3 lane segments prior to the ingress point, respectively. Another issue addressed in this thesis is the managed lane evaluation (MLE) outputs, which include speed, travel time, density, and tolls. In computing the performance measures, the existing VISSIM managed lane evaluation (EVMLE) tool is designed to use the section starting at the point when vehicles are assigned to use MLs, also known as the MLRD point, which is located upstream of the ingress. The longer the MLRD distance from the ingress, the more the EVMLE tool uses the traffic conditions of the MLs traffic before entering the ML in its computations. This study evaluates the impact of the MLRD distance on the EVMLE outputs and presents a proposed algorithm that addresses the EVMLE shortcomings. In order to examine the influence of the MLRD distance on the outputs of the above-mentioned two algorithms, simulation scenarios of varying MLRD distances from 500 ft to 7,000 feet from the ingress were created. For demonstration purposes, only the speed was used to represent other performance measures. The analysis of variance (ANOVA) test was performed to determine whether there was a significant difference in the speed results with the change in the MLRD distance. According to the ANOVA results, the EVMLE tool produced ML speeds that are MLRD dependent, yielding lower speeds with an increased MLRD distance. On the other hand, the ML speed results from the proposed algorithm were fairly constant, regardless of the MLRD distance.
64

Propuesta de medidas de gestión del tránsito orientadas a la seguridad del peatón en la intersección de la Av. Los Héroes con Calle Antonio Buckingham en el distrito de San Juan de Miraflores / Proposal of traffic management measures aimed at pedestrian safety at the intersection Los Héroes Avenue and Antonio Buckingham Street in the district of San Juan de Miraflores

Bazalar Vargas, Massiel Milagros, Charaja Mercado, Kathia Milena 13 August 2019 (has links)
La presente tesis tiene como objetivo establecer una alternativa de solución para mejorar la seguridad del peatón en la intersección Av. Los Héroes con Calle Antonio Buckingham en el distrito de San Juan de Miraflores. La investigación engloba 7 capítulos más las conclusiones, recomendaciones, bibliografía, anexos y planos. El primer, segundo y tercer capítulo abarcan generalidades, marco teórico y la descripción del software Vissim 9, respectivamente. En el cuarto capítulo se realizó un diagnóstico de la situación actual que permitió identificar las deficiencias que generan inseguridad al peatón en el sistema vial. De esta manera, se propusieron soluciones desde el punto de vista peatonal mediante el análisis de tránsito con la metodología del HCM 2010. Existen tres escenarios, el primero es la configuración actual de la vía, de la cual se hace el respectivo análisis vehicular y peatonal, en el segundo escenario se plantea una propuesta de medidas de gestión (semaforización, señalización y cambios geométricos) que funcionan como un sistema eficiente, coordinado y seguro. Finalmente, en el tercer escenario se desarrolla el análisis de la proyección futura de la propuesta. El quinto y sexto capítulo incluyen la propuesta detallada de infraestructura vial y señalización; y la modelación microscópica de la intersección en el software VISSIM 9, respectivamente. El séptimo capítulo desarrolla el análisis, evaluación y validación de la propuesta, esta última mediante juicio de expertos. Al finalizar la investigación se llega la conclusión de que las medidas de gestión adoptadas como solución a la problemática mejorará la intersección de forma efectiva si se implementan. / The objective of this thesis is to establish an alternative solution to improve pedestrian safety at the intersection Los Heroes Avenue with Antonio Buckingham Street in the district of San Juan de Miraflores. The research includes 7 chapters plus conclusions, recommendations, bibliography and annexes. The first, second and third chapters cover generalities, the theoretical framework and the description of the Vissim 9 software, respectively. In the fourth chapter, a diagnosis was made of the current situation that allowed identifying the deficiencies that generate insecurity for pedestrians in the road system. In this way, solutions were proposed from the pedestrian point of view through the traffic analysis with the HCM 2010 methodology. There are three scenarios, the first is the current configuration of the road, from which the respective vehicular and pedestrian analysis is made, in the second scenario, a proposal of management measures is proposed (traffic light, signaling and geometric changes) that function as an efficient, coordinated and secure system. Finally, in the third scenario, the analysis of the future projection of the proposal is developed. The fifth and sixth chapters include the detailed proposal of road infrastructure and signaling; and the microscopic modeling of the intersection in the VISSIM 9 software, respectively. The seventh chapter develops the analysis, evaluation and validation of the proposal, the latter through expert judgment. At the end of the investigation, the conclusion is reached that the management measures adopted as a solution to the problem will improve the intersection effectively if they are implemented. / Tesis
65

Evaluation of the LHOVRA O-function using the microsimulation tool VISSIM

Harirforoush, Homayoun January 2012 (has links)
The growth of serious injuries and fatalities resulting from traffic accidents at intersections is one of the main problems in urban areas. Signal control was proposed as an alternative intersection design on rural roads. There were many reasons behind this, the most outstanding of which was the traffic signals can be used as a cost effective tools for traffic management in urban areas. The LHOVRA technique was intended to improve safety and reduce lost time at signalized intersection along high speed roads. The LHOVRA technique is an isolated traffic control strategy in Sweden which is formed from different concepts. This thesis work is aimed to evaluate the LHOVRA technique with a focus on the O-function. Hence, two different scenarios, one with O-function and one without O-function were implemented in the micro traffic simulation software, VISSIM. VISSIM has been used to simulate the traffic situation of the Gamla Övägen – Albrektsvägen intersection by considering the LHOVRA scenario (with O-function) as well as traditional scenario (without O-function) of the intersection. Field measurements were used as input data for VISSIM simulation. The VISSIM simulation model was calibrated to find a close match between simulated and real data. Finally, a comparison of alternatives was carried out based on traffic performance and traffic safety measurements. The simulation experiment results gained by the comparisons were presented a higher time-to-collision value. The higher time-to-collision value the safer situation is. Both delays and travel time were reduced to primary road traffic.
66

Evaluation of bus terminals using microscopic traffic simulation

Askerud, Caroline, Wall, Sara January 2017 (has links)
Traffic simulation is a safe and efficient tool to investigate infrastructural changes as well as traffic conditions. This master thesis aims to analyse a microscopic traffic simulation method for evaluation of bus terminal capacity. The evaluation is performed by investigating a case study of the bus terminal at Norrköping travel centre. The analysed method, referred to as terminal logic in the thesis, uses a combination of time based and event based simulation. Through the combination of time and event, it is possible to capture all movements within the terminal for individual vehicles. The simulation model is built in the software Vissim. A new travel centre for Norrköping is under development. Among the reasons for a new travel centre is the railway project Ostlänken in the eastern part of Sweden. An evaluation of the bus terminal is interesting due to a suspicion of overcapacity and the opportunity of redesigning. To investigate both the terminal capacity and the terminal logic, three scenarios were implemented. Scenario 1: Current design and frequency Scenario 2: Current design with higher frequency Scenario 3: Decreased number of bus stops with current frequency The results from the scenarios confirm the assumption of overcapacity. The capacity was evaluated based on several different measures, all indicating a low utilization. Even so, the utilization was uneven over time and congestion could still occur when several buses departed at the same time. This was also seen when studying the simulation, which showed congestions when several buses departed at the same time. The case study established the terminal logic to be useful when evaluating capacity at bus terminals. It provides a good understanding of how the terminal operates and captures the movements. However, it was time-consuming to adjust the logic to the studied terminal. This is a disadvantage when investigating more than one alternative. The thesis resulted in two main conclusions. Firstly, a more optimised planning of the buses at Norrköping bus terminal would probably be achievable and lead to less congestions at the exits. Secondly, the terminal logic is a good method to use when evaluating bus terminals but it is not straight forward to implement.
67

Simulating Autonomous Vehicles in a Microscopic Traffic Simulator to Investigate the Effects of Autonomous Vehicles on Roadway Mobility

Lackey, Nathan 27 August 2019 (has links)
No description available.
68

Analysis of Walking and Route-Choice Behavior of Pedestrians inside Public Transfer Stations : A Study on how pedestrians behave in the approaching vicinity of level-change facilities,and how it affects their walking and route-choice behavior

Monte Malveira, Daniel January 2019 (has links)
Pedestrian walking and choice behavior presented was first studied by Fruin in 1971, and since then a lot of research have been carried out in order to understand how humans move and what does make them make choices and obtain certain patterns. In relation to pedestrians, a significant bottleneck inside public stations evaluated by research are the level-change facilities, as Stair Walks and Escalators. The aim of this research is studying how pedestrian behave in the vicinity to stairways and escalators, and how does that affect pedestrian choice, speed and acceleration when choosing one of the two facilities. Also, with a need for more data on pedestrian traffic, further data collection is a big requirement to analyze their behavior and use as tools in future measures. At last, how to optimize the movement of pedestrians in relation to level changes, considering the effects of the movements observed. Two case studies were analysed, Stockholm Central Station and Uppsala Central Station.The study compares data collection methods, tracking methods and previous studies to better fit the scope of this research. The data is backed up from previous research and explains which method better fitted the options available. As a result, video data collection was chosen to collect the data, a semi-automatic tracking software called T-analyst was used to extract speed, trajectories and acceleration from the videos, and microsimulation modelling from VISSIM further investigated different design options to optimize the overall performance and improve travel time in the same area. The analysis found out that there was a possibility to increase the overall performance of the location in higher flow levels, where the most significant queues could be seen, since there was the possibility to achieve higher speeds by modifying the width and position of the stair walks, which allow for a smaller queue in both directions.
69

Fotgängares gånghastigheter i bytespunkter för kollektivtrafik

Jegenberg, Minna, Lundström, Kristina January 2017 (has links)
Walking speeds are an important parameter in the process of designing for example arenas, malls and station environments, to be able to make them safe and comfortable for the users. Previous studies have mainly focused on pedestrian walking speeds at zebra crossings and the results of these are the basis for traffic signal timing. The studies have also investigated the relationship between walking speed and gender, age and density of pedestrians. From the results of these studies, conclusions have been drawn that these three factors have an impact on pedestrian walking speeds. To make microsimulations of pedestrians reflect reality as well as possible, pedestrian walking speeds should be investigated at regular intervals, as walking speeds change with the ongoing change of the composition of the population. In the simulation of station environments, pedestrian speeds should also be used that have been measured in these types of environments. Alternatively, the speeds should be measured at locations near stations, rather than using speeds from zebra crossings. As a step in improving the above-mentioned microsimulations, the aim of this work is to study walking speeds at a public transport hub during rush hour. The work also focuses on connecting walking speeds to each sex and level of crowding. To achieve this goal, video recordings were performed at the exchange point between Stockholms östra and Tekniska högskolan in Stockholm, Sweden, where public transport passengers change between light rail and subway. Analysis of the video films resulted in walking speeds which were higher than those previously measured at zebra crossings. The most obvious factors explaining this are the differences in the environment where the studies were conducted and that the walking speeds in this thesis were measured during rush hour. The results show that simulations of stations and locations nearby should not be based on walking speeds measured at zebra crossings. Analysis of the video films also resulted in the calculated mean walking speed of women being marginally lower than for men. Regarding the link between density of pedestrians and their walking speeds a conclusion can be drawn that at low densities pedestrians have good opportunities to freely select their own walking speed. The freely chosen walking speed which can thus be maintained at low densities can vary widely between different individuals. At higher, unlike at lower densities, it is difficult for pedestrians to maintain a freely chosen speed due to interactions with other pedestrians. The calculated average walking speed at higher densities therefor decreases as the density increases. Interactions with other pedestrians can either mean that a pedestrian is forced to lower the speed or that he or she must walk faster to keep up with the current pace. When analyzing the video films, several other factors effecting the walking speed could be noted. Of these factors, grouping of pedestrians and if the pedestrian is using a phone or carrying luggage could be seen to decrease the pedestrian speed. These factors’ impact on walking speeds was only superficially studied in this thesis, and no reliable conclusions can therefore be drawn. Keywords: Pedestrian walking speed, public transport traffic hub, density of pedestrians, Level of
70

The Calibration And Verification Of Simulation Models For Toll Plazas

Russo, Christopher 01 January 2008 (has links)
A great deal of research has been conducted on Central Florida toll roads to better understand the characteristics of the tolling operation. In this thesis, the development and calibration of a toll plaza simulation models will be analyzed using two simulation programs varying mostly in their modeling theory. The two models utilized are, SHAKER, a deterministic queuing model for vehicles utilizing toll collection facilities, and VISSIM, a globally popular stochastic simulation software. The benefits of simulation models leads to the purpose of this thesis, which is to examine the effectiveness of two toll modeling programs that are similar in purpose but vary in approach and methodology. Both SHAKER and VISSIM toll plaza models have the potential to work as a tool that can estimate the maximum throughput and capacity of toll plazas. Major operational benefits resulting from developing these models are to simulate and evaluate how traffic conditions will change when demand increases, when and if queues increase when a lane is closed due to maintenance or construction, the impact of constructing additional lanes, or determining whether or not the best lane type configuration is currently implemented. To effectively calibrate any model available site data must be used to compare simulation results to for model validity. In an effort to correctly calibrate the SHAKER toll plaza tool and VISSIM model, an extensive field collection procedure was conducted at four Florida Turnpike operated toll facilities located in Central Florida. Each site differed from the others in terms of number of lanes, lane configuration, toll base fee, highway location, traffic demand, and vehicle percentage. The sites chosen for data collection were: the Lake Jesup Mainline Plaza along the Seminole Expressway (SR-417), the Beachline West Expressway Toll Plaza along the SR-528, the Daniel Webster Western Beltway Plaza along SR-429, and the Leesburg Toll Plaza along the Florida Turnpike Mainline SR-91. Upon completion of calibration of the two simulation models it is determined that each of the two software are successful in modeling toll plaza capacity and queuing. As expected, each simulation model does possess benefits over the other in terms of set up time, analysis reporting time, and practicality of results. The SHAKER model setup takes mere seconds in order to create a network and input vehicle, another few seconds to calibrate driving parameters, and roughly 10 additional seconds to report analysis. Conversely, setting up the VISSIM model, even for the most experienced user, can take several hours and the report analysis time can take several more hours as it is dependant on the number of required simulation runs and complexity of the network. VISSIM is most beneficial by the fact that its modeling allows for driver variability while SHAKER assumes equilibrium amongst lane choice and queuing. This creates a more realistic condition to observed traffic patterns. Even though differences are prevalent, it is important that in each simulation model the capacity is accurately simulated and each can be used to benefit operational situations related to toll plaza traffic conditions.

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