Development and validation of a driving simulator for traffic control using field data

This paper presents the development and validation of a driving simulator for ramp traffic control on expressways using a traffic simulator and control (TSC). The TSC consists of two main components: car-following model (CFM), and traffic controller (TC). The CFM simulates the car-following behavior and delivers aggregated traffic parameters to the TC to derive control actions. The CFM and TC are harmonized and integrated in a close-loop control manner, where the effects of the control by the TC are fed-back as inputs for the CFM in real-time applications. Although the following behavior of individual vehicles is simulated, the aggregated outputs such as average speed and flow rate from the model are the parameters of interest. For simplicity in the model development and validation and to capture lane-changing effects, the traffic in the multi-lane expressway where the data were obtained was equivalently represented as a single-lane system. The validation of the CFM was performed at macroscopic level where aggregated outputs from the model were compared to observed data in a segment of the Pan Island Expressway of Singapore under various traffic conditions. The result shows that the simulated speed is not significantly different from the actual speed at 5% significance level, and the aggregated flow rate discrepancies fall in a small range, from 2.21% to 3.15%. This shows that the TSC model is a reliable model for traffic simulation and control applications

Análise energético-ambiental de rotundas

Mestrado em Engenharia MecânicaA implementação de mecanismos de acalmia de tráfego tem sido importante para combater os índices de sinistralidade, onde uma das causas principais é o excesso de velocidade. Uma das soluções passa pela implementação de obstáculos físicos de modo a obrigar o condutor a reduzir a velocidade, exemplo disso é o recurso a rotundas. Com as rotundas garante-se uma melhoria ao nível de segurança rodoviária, contudo os estudos existentes para avaliar o impacto energético e ambiental de rotundas cingem-se a soluções convencionais de uma via e de várias vias de circulação. A presente dissertação propõe-se fazer uma análise em termos de capacidade e de emissões de uma rotunda com uma via de circulação localizada na cidade de Coimbra, que apresentava congestionamento num dos seus ramos de acesso, com posterior avaliação de duas alternativas para o mesmo local. A primeira, sugere-se a transformação da atual rotunda de uma via para uma rotunda tradicional de duas vias e, na segunda alternativa, propõe-se a implementação de uma turbo-rotunda. Para atingir os objetivos propostos, recorreu-se ao simulador de tráfego VISSIM para modelar o cenário de referência, que foi calibrado com dados recolhidos experimentalmente e posteriormente validado utilizando como parâmetros de avaliação os volumes de tráfego, os tempos de viagem e a velocidade média. Finalmente, quantificaram-se as emissões de poluentes, que foram estimadas utilizando a metodologia baseada no conceito de potência específica do veículo (VSP). Com o cenário devidamente validado procedeu-se à análise comparativa dos três cenários, utilizando os tempos de viagem, a velocidade média, modos VSP e emissões dos poluentes CO2, CO, NOx e HC. Os resultados obtidos indicam que as duas soluções propostas apresentam melhorias a todos os níveis. Os tempos de viagem diminuíram em cerca de 14 % para ambos os cenários alternativos, consequência de um aumento de velocidade em cerca de 13%. No que diz respeito às emissões, a rotunda de duas vias apresentou-se como a melhor solução ambiental em termos de CO2 e NOx, apresentando uma diminuição de 27% e 19%, respetivamente, face à rotunda de uma via. Por sua vez, a turbo-rotunda teve o melhor desempenho ambiental ao nível dos poluentes locais CO e HC, com 16% e 30%, respetivamente. Conclui-se assim que se justifica a substituição da rotunda de uma via por uma rotunda de duas vias. A turbo-rotunda não se afigura a melhor alternativa, uma vez que ocorrem elevadas percentagens de viragem à esquerda a partir do ramo mais congestionado. Assim sendo, a opção por esta alternativa faria mais sentido se houvesse mais veículos a realizarem viragens na primeira saída.The implementation of traffic calming mechanisms has been important to avoid road accidents, where one of the main causes is excessive speed. One solution is to implement physical obstacles (such as roundabouts) in order to compel the driver to reduce vehicle speed. Roundabouts can lead to an improvement in road safety, but existing studies to assess the impact on energy and emissions is confined to single and two-lane roundabouts. This dissertation proposes to make an analysis in terms of capacity and emissions caused by a single lane roundabout in the city of Coimbra, with traffic congestion in one of its branches. Subsequently, the results were compared with two alternatives for the same place: a two-lane roundabout and a turboroundabout. To achieve the proposed objectives, traffic simulator VISSIM was used to model the reference scenario, which was calibrated with experimentally collected data. The evaluation parameters (such as traffic volumes, travel times, average speed) were subsequently validated. Finally, emissions were estimated using the methodology “Vehicle Specific Power” (VSP). After the validation of the reference scenario there was a comparative analysis of the three scenarios, using travel times, average speed, modes VSP and emissions of pollutants CO2, CO, NOx and HC. The results indicate that the two solutions lead to improvements at all levels. Travel times decreased about 14% since there was an existing speed increase of 13%. Two-way roundabout is the best solution in terms of CO2 and NOx emissions, showing a decrease of 27% and 19%, respectively, compared to the single lane roundabout. Turbo-roundabout had the best performance in terms of CO and HC, with a reduction of 16% and 30%, respectively. The main conclusion is that the replacement of this single lane roundabout by a two-lane roundabout can be justified, due to its advantages. The turboroundabout leads to a worse traffic performance in this study due to the fact that high percentages of left turn from the more congested branch occurred. Thus, the choice of this alternative would be preferred if there were more vehicles choosing the first exit

Análise comparativa de diferentes tipos de interseções em meio urbano

Mestrado em Engenharia CivilAtualmente, devido à melhoria das condições de vida das sociedades modernas tem-se verificado um crescimento do uso do transporte rodoviário, nomeadamente do transporte individual. Por esta razão, o controlo de tráfego nas interseções urbanas tornou-se mais exigente e importante, afetando com isso a capacidade, o tempo de viagem, a eficiência de desempenho e segurança de toda a rede de tráfego. Esta dissertação pretende contribuir para o estudo e avaliação da substituição de uma interseção semaforizada por uma rotunda em Perafita (Matosinhos), avaliando o desempenho de ambas as interseções e comparando-as. Para a comparação e caracterização do desempenho de ambas as interseções foi necessário recorrer a indicadores de desempenho, que se basearam no volume de tráfego que chega à interseção. Desta forma, foram utilizados como indicadores, a capacidade, o grau de saturação, o atraso médio por veículo e o comprimento das filas de espera. Para estimar os valores desses indicadores foram utilizadas metodologias específicas para cada interseção (TRL, SETRA, FCTUC e HCM) e um software de simulação de tráfego, o AIMSUN. Primeiramente, os resultados da simulação foram comparados com os resultados dos modelos clássicos, ficando patente as vantagens do recurso à microssimulação. Em segundo, o impacto da substituição da interseção semaforizada pela rotunda, utilizando os resultados obtidos pelo software, determinaram que a rotunda, para aquela localização e condições de tráfego, apresenta um melhor desempenho previsto, uma vez que, a simulação da rotunda face à interseção semaforizada apresentou maior capacidade, menor atraso médio, menor comprimento de filas de espera, menor grau de saturação, menor tempo de viagem e menor tempo de paragem por veículo. O que demonstra que em termos de condições operacionais, a rotunda traz mais vantagens para todo o tipo de veículos.Currently, due to the improvement of the living conditions of modern societies is possible to verify an increase in the road transport utilization, particularly the individual transport. For this reason, traffic control at urban intersections has become more demanding and crucial, influencing the capacity, travel time, performance efficiency and safety of the entire road network. This thesis intends to contribute to the study and evaluation of the replacement of an intersection with traffic lights by a roundabout in Perafita (Matosinhos), assessing the performance of both intersections and comparing them. For comparison and description of the performance of both intersections, it was necessary to use performance indicators, which were based on the volume of traffic that reaches the intersection. In this way, the capacity, degree of saturation, average delay per vehicle and length of waiting queues were used as indicators. To estimate the values of these indicators, specific methodologies were used for each intersection (TRL, SETRA, FCTUC, and HCM) and the traffic simulation software, AIMSUN. Firstly, the results of the simulation were compared with the results of the classical models, where the advantages of the use of microsimulation were noticeable. Secondly, the impact of the replacement of the traffic light intersection by the roundabout, using the results obtained by the software, determined that the roundabout, due to its location and traffic conditions, has a better predicted performance. Since the simulation of the roundabout compared with the traffic light intersection showed higher capacity, lower average delay, shorter queue length, lower saturation, shorter travel time and shorter vehicle downtime is possible to conclude that in terms of operating conditions, the roundabout brings more advantages for all types of vehicles

Calibração de modelos microscópicos de simulação de tráfego em redes urbanas

Tese de mestrado integrado. Engenharia Civil (especialização em Vias de Comunicação). Faculdade de Engenharia. Universidade do Porto. 200

Strategies for the sustainable redevelopment of residential buildings in Ulaanbaatar, Mongolia

The current condition of central Ulaanbaatar’s residential buildings and their associated infrastructure is in a critical state. It is important to study the current urban renewal process in Ulaanbaatar city, with a focus on solving recognized practical problems that arose from the necessity to improve a city centre neighbourhood. This study investigated how the redevelopment process of residential buildings in Ulaanbaatar city, Mongolia can be implemented in a sustainable way. It explored potential issues associated with residential redevelopment; analysis and integration of the research findings provides a framework for sustainable residential redevelopment. A combined quantitative and qualitative research approach was used in this study. The researcher conducted a questionnaire survey to residents living in Ulaanbaatar and interviewed stakeholders and government authorities, to obtain a better understanding of potential problems which may influence redevelopment. The survey of residents in dilapidated buildings established the nature of resident’s opinions of urban renewal and identified the condition of their buildings. It showed that they had strong concerns about whether redevelopment involving new multi-storey redevelopments built on site of their current residences is appropriate for the area and how it might influence their interest. The interviews with building professionals and local community representatives helped to ascertain issues affecting the refurbishment or redevelopment of dilapidated residential buildings. Discussions with personnel from relevant government agencies produced a deeper understanding of current urban renewal policy in Ulaanbaatar city, existing and prospective issues for urban renewal, and generated suggestions to deal with them. The survey findings were aligned with the triple bottom line principles of sustainability and further categorized into different phases of a project life cycle, based on which a framework was developed to support the sustainable residential redevelopment. The framework integrated critical factors and issues likely to affect the residential redevelopment in the different phases of a project. At the end of the study the framework was validated through a questionnaire survey among urban development experts to determine whether a framework reasonably fulfils its intended use. It is expected that the framework will help to deal with existing issues and avoid potential problems associated with residential redevelopment in Ulaanbaatar city. Also, the study will contribute to the general field of urban renewal studies

Aplicação de modelos de análise de tráfego em ambiente real, incluindo a recolha de dados com recurso a drone.

Relatório de estágio para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização em Vias de Comunicação e Transportes.A aplicação de modelos nos estudos de tráfego urbano tem apresentado grande evolução. Esse facto está ligado a dois motivos principais: a dificuldade e o custo em concretizar experiências em escala real, assim como possíveis consequências em questões de segurança; e a capacidade que os modelos possuem para testar, comparar e avaliar alternativas, sem a necessidade de as mesmas serem concretizadas. Este documento se faz presente para expor, descrever e refletir sobre as atividades e os estudos que foram realizados durante o período do estágio académico, que decorreu na empresa de consultoria FJ. Consultores, Lda., visando a futura conclusão do presente mestrado que se decorre e a transparência dos conhecimentos interiorizados. Junto ao desenvolvimento desse relatório de estágio foi possível adicionar uma atividade de carater investigativo, dividida em dois cenários distintos, cada um deles com duas etapas: a primeira etapa explora técnicas de recolha de dados com recurso ao drone adquirido pelo ISEL, no âmbito do protocolo com a empresa DatafromSky, que é empregue nas análises dos dados recolhidos, devido a ser especialista na aplicação de inteligência artificial para o desenvolvimento de técnicas inovadoras de análise de tráfego. Na segunda etapa dessa atividade é desenvolvido um modelo de simulação, recorrendo ao software Vissim, pertencente ao grupo PTV, que se trata de um dos principais programas de simulação microscópica, apresentando um modelo realista e preciso em todos os seus detalhes, disponibilizando condições ideias para se estudar as condições de tráfego. Este software é uma referência, a nível mundial, na área da engenharia de tráfego e atualmente é utilizado nas universidades, no setor público e nas empresas de engenharia. Por fim, acredita-se que o desenvolvimento do presente relatório alcança pontos importantes como: descrição e análise crítica das atividades, reflexão sobre as problemáticas apresentadas, transparência dos conhecimentos absorvidos e uma análise global e fidedigna para com este estágio académico.The application of models in urban traffic studies has shown great evolution. This fact is linked to two main reasons: the difficulty and cost of conducting full-scale experiments, as well as possible consequences in safety issues; and the ability that models have to test, compare and evaluate alternatives, without the need for them to be realized. This document is presented to expose, describe, and reflect on the activities and studies that were carried out during the academic internship period, which took place at the consulting firm FJ. Consultores, Lda., aiming at the future conclusion of the present master's program and the transparency of the knowledge internalized. Along with the development of this internship report, it was possible to add an activity of investigative nature, divided into two distinct scenarios, each of them with two stages: the first stage explores data collection techniques using the drone acquired by ISEL, under the protocol with the company DatafromSky, which is used in the analysis of the collected data, due to be a specialist in the application of artificial intelligence for the development of innovative techniques of traffic analysis.In the second stage of this activity, a simulation model is developed, using the Vissim software, belonging to the PTV group, which is one of the main microscopic simulation programs, presenting a realistic and precise model in all its details, providing ideal conditions to study traffic conditions. This software is a worldwide reference in the area of traffic engineering and is currently used in universities, the public sector, and engineering companies. Finally, it is believed that the development of this report achieves important points such as: description and critical analysis of the activities, reflection on the problems presented, transparency of the knowledge absorbed and a global and reliable analysis of this academic internship.N/

Aplicação de modelos de tráfego (DRACULA) na avaliação dos impactos em redes rodoviárias urbanas resultantes das alterações nas infra-estruturas

Tese de mestrado integrado. Engenharia Civil (especialização em Vias de Comunicação). Faculdade de Engenharia. Universidade do Porto. 200

Development of a sustainability management system for petroleum companies

Petroleum companies contribute to the largest proportion of environmental degradation in Libya. In support, the 2014 environmental performance index ranks Libya 120th out of 178 countries which suggest the country faces serious environmental degradation, unlike the developed countries. It is necessary to critically investigate the key environmental sustainability issues faced by the Libyan petroleum companies to develop a Sustainability Management System (SMS). The research aims to develop a SMS for the petroleum companies through critical investigations of sustainability-related impacts, issues, and barriers to the sustainability approaches, and to develop suggestions for reduction of the adverse effects. The mixed-methods approach involved a survey-based questionnaire and field visits for interviews (semi-structured) with a number of stakeholders. An Environmental Impact Assessment study (EIA) was also conducted as a case study in one of the field visits. Furthermore, a Life Cycle Assessment (LCA) study to Libyan crude oil. The survey questionnaire was used to collect data from the workers. The interviews provide insight into the concerns, barriers, and challenges from the policy makers, environmentalists, and industrial professionals at a senior level. The use of life-cycle assessment (LCA) has further outlined the environmental impact assessment (EIA) of the petroleum industry in Libya. Data analysis was performed through triangulation of the qualitative and quantitative approaches. The LCA results show that there are diverse environmental impacts caused by the Libyan petroleum industry, which require the implementation of an SMS to minimise these impacts. EIA results revealed high levels of environmental impacts mainly associated with air emissions such as GHGs and hazardous H2S along with oil spillages, at the upstream and downstream levels of production. Interviews and the survey confirmed that there are issues/obstacles associated with sustainability in the Libyan petroleum sector which limits the provision of quality and efficient services. The current approaches adopted by companies are neither matched with the developments in the sustainability field in other developed countries nor fit, with the managerial or governance processes. The proposed SMS, applicable in developing countries, proposes the incorporation of environmental factors to increase the scope of stakeholders’ participation in the process, as well as the environmental performance of petroleum companies