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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.
51

Propuesta de reducción de los tiempos de viaje vehicular en el óvalo ubicado en la intersección de la Av. Alfredo Mendiola – Av. Eduardo de Habich, a través del sistema de semaforización inteligente RAMP meter / Proposal for reduction of vehicle travel times in the roundabout located on the intersection Alfredo Mendiola Av. – Eduardo de Habich Av. through RAMP meter singal control smart system

Mariluz Cuadros, Luis Eduardo 26 February 2020 (has links)
La congestión vehicular en Lima es caótica dada la escaza infraestructura vial y el acelerado aumento del parque automotor. En contraste, esta investigación propone implementar el sistema de semaforización inteligente, Ramp Meter, basado en el algoritmo AMS-AG, para reducir los tiempos de viaje vehicular en el óvalo Habich, ubicado en el distrito de San Martín de Porres. La metodología propuesta consta en la recolección de datos estáticos y registro de una lista de verificaciones. Luego se procede con la toma de datos de entrada para construir el modelo, tales como; flujos, velocidades y tiempos de viaje. El primer paquete de datos es utilizado para la construcción y calibración del modelo en el software de microsimulación PTV Vissim 9.0, y el segundo para la validación del modelo. De acuerdo con los resultados de los parámetros de performance vehicular (demora, tiempo de viaje y velocidad) y peatonal (tiempo de viaje, velocidad) de la situación actual y lista de verificaciones, se realiza la propuesta de solución. Del mismo modo, a una proyección a 15 años se estima su funcionalidad en el mediano plazo. Se concluye que la propuesta de mejora a través de la implementación del Ramp Meter, basado en el algoritmo AMS-AG, ofrece mejoras en relación con el performance vehicular, sin embargo, pierde rendimiento a medida que incrementa el flujo vehicular. Cumple con el objetivo principal de la investigación de reducirse los tiempos de viaje vehicular. Por último, se afirma que la inversión económica que demanda es una alternativa viable y rentable. / Vehicle congestion in Lima is chaotic given the lack of road infrastructure and the rapid increase in the number of vehicles. In contrast, this research proposes to implement the intelligent traffic light system, Ramp Meter, based on the AMS-AG algorithm, to reduce vehicle travel times at the Habich roundabout, in San Martin de Porres district. The proposed methodology consists of the collection of static data and registering a checklist. Then, we proceed with taking input data to build the model, such as flows, speed and travels times. The first data packet is used for the construction and calibration of the model in the PTV Vissim 9.0 microsimulation software, and the second one is used for model validation. According to the results of the parameters of vehicular performance (delay, travel time and speed) and pedestrian (travel time and speed) of the current situation and checklist, the proposed solution for roundabout is made. Similarly, at a projection to 15 years its functionality is estimated in the medium term. It is concluded that the improvement proposal through the implementation of the Ramp Meter, based on the AMS-AG algorithm, offers improvements in relation to vehicle performance, however, it loses performance as vehicle flow increases. It fulfills the main objective of the research to reduce vehicle travel times. Finally, it is stated that economic investment that it demands is viable and profitable alternative. / Tesis
52

Curbside Management and Routing Strategies that Incorporates Curbside Availability Information

Blixt, Richard, Lindgren, Carl January 2020 (has links)
Vehicles that today are searching for a place to stop impacts other vehicles in cities. It can also be seen that the number of vehicles that desire to conduct a pick-up or drop-off increases with an increased number of ride-hailing services. New technology routing advises for such vehicles could improve the overall performance of a traffic network. This thesis analyses therefore how a routing strategy, that incorporates curbside availability information, can impact the performance. To analyse the effects of how curbside availability information can impact a network, a microscopic traffic simulation model was constructed in PTV Vissim and two different routing strategies were developed and implemented in the model. One strategy that represents the scenario of today where vehicles searches the traffic network while attempting to make a stop at a pick-up and drop-off slot. The second strategy routes vehicles to a slot based on curbside availability information. This strategy directs vehicles to an available slot and therefore reduces the time a vehicle is cruising before a stop has been made. A simulation experiment was set-up to compare the strategies that were developed with different penetration rates of vehicles that desired to stop. The results shows that the average travel time can be reduced with up to 25.2\% when vehicles have information compared to the scenario with no information. Similar findings is identified for average delay per vehicle which is reduced with up to 49.0\% and average traveled distance decreased with up to 15.5\%. The results of this thesis needs however to be studied in a wider context in order to draw reliable conclusions. The thesis propose further investigations whether a strategy that incorporates availability information can be implemented in a real world scenario and further investigations whether an implementation of a strategy like this would be socioeconomic beneficial.
53

Dopravně-inženýrská opatření na ul. Svatoplukově v Brně / Traffic Organizing of Svatoplukova Street in Brno

Bátora, Filip Unknown Date (has links)
The main goal of my diploma thesis is the design of transport-engineering measures on the Svatoplukova street with the focus on the finalization of the Great Brno ring road and the following changes of traffic intensity. For the implementation and simulation of my designed measures, I used the PTV Vissim modeling software. The simulation outputs were then evaluated and transformed into recommendations to be taken into consideration during the creation of future traffic-engineering measures in the given area.
54

Using Micro-Simulation Modeling to Evaluate Transit Signal Priority in Small-to-Medium Sized Urban Areas; Comparative Review of Vissim and S-Paramics Burlington, Vermont Case Study

Tyros, Joseph C 01 January 2012 (has links) (PDF)
With many advances in transportation technology, micro-simulation models have proven to be a useful tool in transportation engineering alternative analyses. Micro-simulation software packages can be used to quickly and efficiently design new transportation infrastructure and strategies, while helping transportation planners and traffic engineers identify possible problems that might arise in a particular design alternative. Over the years these simulation packages have become more advanced, and their capabilities in terms of modeling complex, intricate intersections and producing useful outputs for analysis have increased. Today’s simulations can reproduce many facets of transportation design alternatives while generating outputs that help increase efficiency, reduce cost, optimize financing, and improve safety. Recently micro-simulation models have been employed in the analysis and design of alternative transit signal priority (TSP) strategies. This research reviews the similarities, differences and functional capabilities of two micro-simulation software packages: 1) VISSIM, and 2) S-Paramics. A special effort is made to discuss the usefulness of each package when used to analyze TSP alternatives for small and medium sized urban areas, where data and staff availability are typically limited. The paper includes a case study of Burlington, Vermont in which each software package is employed to evaluate several alternative TSP strategies. Each package is evaluated in terms of ease of use, usefulness of outputs, and consistency of results. The results of the evaluation are intended to guide planners and traffic engineers in small and medium urban areas in the selection of an appropriate simulation package for TSP analysis and design.
55

Projection Algorithm for Improved Corridor Signal Coordination

Feng, Cong 23 December 2009 (has links)
No description available.
56

A Novel Approach to Dilemma Zone Problem for High Speed Signalized Intersections

Raavi, Venkata Suresh 21 May 2010 (has links)
No description available.
57

Evaluation the level of service at a roundabout : A case study on Al-Ibrahimeya roundabout in Alexandria, Egypt

Iscan, Neval January 2019 (has links)
The capacity of today’s transportation network in Alexandria cannot handle the increasing number of vehicles. The root of traffic congestion in Alexandria is most likely as result of urban planning failure, an inadequate public transportation network, strong population growth, lack of enforcement of traffic laws, complex spatial street network and poor road quality.The aim with this thesis is to simulate various traffic scenarios for the purpose of studying, evaluating and improving the traffic conditions on the intersection Al-Ibrahimeya, however, for long-term efficiency and improvement in Al-Ibrahimeya, the traffic conditions in the entire system be improved.In this thesis, a model was built in the microscopic software VISSIM and macroscopic software SYNCHRO. The model is calibrated based on data collected from video recording. Two alternative solutions to overcome the congested traffic conditions were tested. Signalization has been the main alternative solution performed for intersection Al- Ibrahimeya.The simulation results showed some improvements in terms of delay and travel time. Roundabouts are usually suitable for under low to mid traffic conditions. When there is a heavy traffic flow, as in this case, roundabouts are not suitable and may cause problem in the network. Implementing signals led to some decrease in the entering and exiting flows because the total network became more controlled. However, an organized and well-functioning signalization program helped to reduce delay and travel time in most of routes.
58

Traffic Conflict Analysis Under Fog Conditions Using Computer Simulation

Zhang, Binya 01 January 2015 (has links)
The weather condition is a crucial influence factor on road safety issues. Fog is one of the most noticeable weather conditions, which has a significant impact on traffic safety. Such condition reduces the road's visibility and consequently can affect drivers' vision, perception, and judgments. The statistical data shows that many crashes are directly or indirectly caused by the low-visibility weather condition. Hence, it is necessary for road traffic engineers to study the relationship of road traffic accidents and their influence factors. Among these factors, the traffic volume and the speed limits in poor visibility areas are the primary reasons that can affect the types and occurring locations of road accidents. In this thesis, microscopic traffic simulation, through the use of VISSIM software, was used to study the road safety issue and its influencing factors due to limited visibility. A basic simulation model was built based on previously collected field data to simulate Interstate 4 (I-4)'s environment, geometry characteristics, and the basic traffic volume composition conditions. On the foundation of the basic simulation model, an experimental model was built to study the conflicts' types and distribution places under several different scenarios. Taking into consideration the entire 4-mile study area on I-4, this area was divided into 3 segments: section 1 with clear visibility, fog area of low visibility, and section 2 with clear visibility. Lower speed limits in the fog area, which were less than the limits in no-fog areas, were set to investigate the different speed limits' influence on the two main types of traffic conflicts: lane-change conflicts and rear-end conflicts. The experimental model generated several groups of traffic trajectory data files. The vehicle conflicts data were stored in these trajectory data files which, contains the conflict locations' coordinates, conflict time, time-to-conflict, and post-encroachment-time among other measures. The Surrogate Safety Assessment Model (SSAM), developed by the Federal Highway Administration, was applied to analyze these conflict data. From the analysis results, it is found that the traffic volume is an important factor, which has a large effect on the number of conflicts. The number of lane-change and rear-end conflicts increases along with the traffic volume growth. Another finding is that the difference between the speed limits in the fog area and in the no-fog areas is another significant factor that impacts the conflicts' frequency. Larger difference between the speed limits in two nearing road sections always leads to more accidents due to the inadequate reaction time for vehicle drivers to brake in time. And comparing to the scenarios that with the reduced speed limits in the low visibility zone, the condition that without the reduced speed limit has higher conflict number, which indicates that the it is necessary to put a lower speed limit in the fog zone which has a lower visibility. The results of this research have a certain reference value for studying the relationship between the road traffic conflicts and the impacts of different speed limits under fog condition. Overall, the findings of this research suggest follow up studies to further investigate possible relationships between conflicts as observed by simulation models and reported crashes in fog areas.
59

Assessing the Impact of Bicycle Infrastructure and Modal Shift on Traffic Operations and Safety Using Microsimulation

Lee, Katherine E. 01 March 2022 (has links) (PDF)
A transportation system designed to prioritize the mobility of automobiles cannot accommodate the growing number of road users. The Complete Streets policy plays a crucial part in transforming streets to accommodate multiple modes of transportation, especially active modes like biking and walking. Complete streets are referred to as streets designed for everyone and enable safety and mobility to all users. A strategy of complete streets transformation is to connect isolated complete street segments to form a complete network that improves active mobility and public transit ridership. This research assessed the impact of efficiently and equitably connecting and expanding the biking network using dedicated lanes on the safety and operation of the network in Atlanta, Georgia. These connections are aimed at increasing the multimodal use of the streets in midtown and downtown Atlanta and achieving the mobility and public health goals through the integration of various modes of travel. The evaluation was done by modeling a well-calibrated and validated network of Midtown and Downtown Atlanta in VISSIM using existing travel demand and traffic design conditions (i.e., the baseline or Scenario 0). A total of three different conditions: existing, proposed, and alternative conditions, were modeled to see the effectiveness of bike infrastructure design improvement and expansion. Three scenarios were then modeled as variations of modal demand of the different condition models. Scenarios modeled are based on input from the City and Community stakeholders. Using the trajectory data from microsimulation, the surrogate safety assessment model (SSAM) from FHWA was used to analyze the safety effect on the bike infrastructure improvement and expansion. Results of this study showed a positive impact of complete streets transformation on the streets of Midtown and Downtown Atlanta. These impacts are quantified in this thesis.
60

Bus Rapid Transit design parameters and their impact on travel times : A micro-simulation study of boarding and alighting through all doors and bus lanes

Berg Wincent, Boel January 2021 (has links)
Sweden has defined a national transportation objective that aim at making public transportation the most attractive option in more situations. One way of making public transportation mote attractive is to ensure that it is rapid. BRT stands for Bus Rapid Transit and is concept that ensures speed and reliability of public transportation buses through combined priority measures. However, accessibility measures for urban buses are often compromised and not prioritized politically. If the travel time saved for these measures can be estimated, then they are more likely to be implemented. Two components that have been defined for Swedish BRT were tested on a proposed BRT corridor in the city of Södertälje through microsimulation tool VISSIM. The two components that were tested was boarding and alighting through all doors and bus lanes, both median and curb side. The components were tested on a 3,2 km long corridor using the current actuated traffic signal that was currently in use. To test the measures a sensitivity analysis was carried out with three different levels of traffic and five different passenger levels for boarding and alighting. Only the impact on travel time for the bus was studied. The travel time savings from the measure boarding and alighting through all doors was 1 to 3 percent but only significant for the higher levels of boarding with an average of 12 to 15 boarding passengers per stop. The travel time savings of the curb side bus lane with actuated traffic signals was estimated to be up to 5 percent and for the median bus lane up to 11 percent in congested traffic conditions.

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