A crise do transporte a??reo no Brasil: 2006-2007

Este estudo de caso aborda a crise vivida pelo setor de transporte a??reo brasileiro nos anos de 2006 e 2007. Deflagrada por um acidente de vulto, a crise teve como protagonistas os controladores de tr??fego a??reo, que, sob suspeita de falha funcional e comunica????o dif??cil com as autoridades do setor, reagiram por meio de uma estrat??gia de opera????o-padr??o (greve branca). Essa situa????o, somada ?? escassez de pessoal, provocou, de novembro de 2006 at?? meados de 2007, o descontrole operacional dos principais aeroportos do pa??s, com grandes preju??zos aos usu??rios. Um novo acidente a??reo, no decorrer da crise, agravou ainda mais a situa????o do setor, expondo defici??ncias estruturais e profissionais ?? opini??o p??blica brasileira, em uma ??rea at?? ent??o considerada segura. O caso relata as tentativas de equacionamento da crise por parte das autoridades respons??veis pela pol??tica de transporte a??reo, frente ao descontentamento e ??s reivindica????es dos controladores de tr??fego a??reo e ?? indigna????o da sociedade. O objetivo do estudo de caso ?? ilustrar uma situa????o de crise e de processo de negocia????o, tendo sido originalmente utilizado em uma oficina sobre negocia????es no setor p??blico. O caso pode ser utilizado como material de apoio em cursos que abordem, entre outros, os seguintes t??picos: negocia????o, gest??o de crises, comunica????o e planejamento estrat??gico

Controlo de tráfego

O crescente número de automóveis nas ruas das grandes cidades, assim como o crescente número de transportes urbanos para atender o crescimento das populações, veio fazer com que as cidades cada vez mais fiquem mais congestionadas e mais propícias para acidentes envolvendo viaturas e peões. Devido a isso, foram criados sistemas de controlo de tráfego capazes de melhorar o tráfego urbano nas cidades, sem deixar de lado as preocupações com os peões e nem com as emissões de poluentes para o ar. Baseado nesse cenário, este trabalho tem como objetivo abordar as possíveis soluções existentes no mercado para melhorar o fluxo das viaturas, principalmente dos transportes colectivos, com prioridades para viaturas de emergências e autocarros, assim como, as passagens de peões, e sistemas de mobilidade urbana. Desempenho do transporte público pode ser melhorado através de um melhor controlo e gerenciamento de tráfego em geral. Nos testes realizados em campo: foi medida a velocidade de viagem do autocarro no cruzamento fixo (Praça de Espanha), e correlacionando-os com intervalos do ciclo dos semáforos para este cruzamento. A flexibilidade do controlador actuando, com o auxílio de detectores de veículos, sendo capaz de variar os intervalos dentro do ciclo, bem como o volume de carros e de prestações em velocidade de viagem do autocarro. Resultados mostram que, durante o período em estudo, os benefícios de velocidade da viagem do autocarro, seria possível, através de um verdadeiro controlo de tempo feedback de cooperação entre as áreas urbanas de controlo de tráfego (Gertrude) e do sistema de localização de veículos de transportes públicos (SAEIP). Ao longo prazo, sugerimos a implantação de um sistema integrado. Fazendo com que o volume no carro seja reduzido. Este efeito leva também, a um aumento da velocidade comercial do autocarro urbano, da mesma forma como foi proposto em nossa experiência.

Solving a signalized traffic intersection problem with an hyperbolic penalty function

Mathematical Program with Complementarity Constraints (MPCC) finds many applications in fields such as engineering design, economic equilibrium and mathematical programming theory itself. A queueing system model resulting from a single signalized intersection regulated by pre-timed control in traffic network is considered. The model is formulated as an MPCC problem. A MATLAB implementation based on an hyperbolic penalty function is used to solve this practical problem, computing the total average waiting time of the vehicles in all queues and the green split allocation. The problem was codified in AMPL.

Simulation and dynamics of freeway traffic

This paper presents the new package entitled Simulator of Intelligent Transportation Systems (SITS) and a computational oriented analysis of traffic dynamics. The SITS adopts a microscopic simulation approach to reproduce real traffic conditions considering different types of vehicles, drivers and roads. A set of experiments with the SITS reveal the dynamic phenomena exhibited by this kind of system. For this purpose a modelling formalism is developed that embeds the statistics and the Laplace transform. The results make possible the adoption of classical system theory tools and point out that it is possible to study traffic systems taking advantage of the knowledge gathered with automatic control algorithms. A complementary perspective for the analysis of the traffic flow is also quantified through the entropy measure.

Satellizing Galileo? Non-state Authority and Interoperability Standards in the European Global Navigation Satellite System

This paper explores the extent and limits of non-state authority in international affairs. While a number of studies have emphasised the role of state support and the ability of strategically situated actors to capture regulatory processes, they often fail to unpack the conditions under which this takes place. In order to probe the assumption that structural market power, backed by political support, equates regulatory capture, the article examines the interplay of political and economic considerations in the negotiations to establish worldwide interoperability standards needed for the development of Galileo as a genuinely European global navigation satellite system under civil control. It argues that industries supported and identified as strategic by public actors are more likely to capture standardisation processes than those with the largest market share expected to be created by the standards. This suggests that the influence of industries in space, air and maritime traffic control closely related to the militaro-industrial complex remains disproportionate in comparison to the prospective market of location-based services expected to vastly transform business practices, labour relations and many aspects of our daily life.

Conceiving Comparative Policy Analysis : Implementing Air Quality Improvement Programs

The comparative analysis of air quality control policies provides an interesting field for studies of comparative policy analysis including program formulation and implementation processes. In European countries, the problem is comparable, whereas implementation structures, programs and policy impacts vary to a considerable extent. Analysis testing possibilities and constraints of air control policies under varying conditions are likely to contribute to a further development of a theory of policy analysis. This paper presents the analytical framework applied in a continuing empirical study explaining program formulation and implementation processes with respect to the different actors involved. Concrete emitter behavior can be explained by interaction processes at the very local level, by program elements of national legislation, and by structural constraints under which such programs are produced.

Portable School Stop Signs and Other Non-Uniform School Stop Control Devices, HR-190, 1978

Portable (roll-out) stop signs are used at school crossings in over 300 cities in Iowa. Their use conforms to the Code of Iowa, although it is not consistent with the provisions of the Manual on Uniform Traffic Control Devices adopted for nationwide application. A survey indicated that most users in Iowa believe that portable stop signs provide effective protection at school crossings, and favor their continued use. Other non-uniform signs that fold or rotate to display a STOP message only during certain hours are used at school crossings in over 60 cities in Iowa. Their use does not conform to either the Code of Iowa or the Manual on Uniform Traffic Control Devices. Users of these devices also tend to favor their continued use. A survey of other states indicated that use of temporary devices similar to those used in Iowa is not generally sanctioned. Some unsanctioned use apparently occurs in several states, however. A different type of portable stop sign for school crossings is authorized and widely used in one state. Portable stop signs similar to those used in Iowa are authorized in another state, although their use is quite limited. A few reports in the literature reviewed for this research discussed the use of portable stop signs. The authors of these reports uniformly recommended against the use of portable or temporary traffic control devices. Various reasons for this recommendation were given, although data to support the recommendation were not offered. As part of this research, field surveys were conducted at 54 locations in 33 communities where temporary stop control devices were in use at school crossings. Research personnel observed the obedience to stop control and measured the vehicular delay incurred. Stopped delay averaged 1.89 seconds/entering vehicle. Only 36.6 percent of the vehicles were observed to come to a complete stop at the study locations controlled by temporary stop control devices. However, this level of obedience does not differ from that observed at intersections controlled by permanent stop signs. Accident experience was compiled for 76 intersections in 33 communities in Iowa where temporary stop signs were used and, for comparative purposes, at 76 comparable intersections having other forms of control or operating without stop control. There were no significant differences in accident experience An economic analysis of vehicle operating costs, delay costs, and other costs indicated that temporary stop control generated costs only about 12 percent as great as permanent stop control for a street having a school crossing. Midblock pedestrian-actuated signals were shown to be cost effective in comparison with temporary stop signs under the conditions of use assumed. Such signals could be used effectively at a number of locations where temporary stop signs are being used. The results of this research do not provide a basis for recommending that use of portable stop signs be prohibited. However, erratic patterns of use of these devices and inadequate designs suggest that improved standards for their use are needed. Accordingly, nine recommendations are presented to enhance the efficiency of vehicular flow at school crossings, without causing a decline in the level of pedestrian protection being afforded.

Evaluation of Maturity and Pulse Velocity Measurements for PCC Traffic Opening Decisions, HR-380, 1998

Concrete paving is often at a disadvantage in terms of pavement type selection due to the time of curing required prior to opening the pavement to traffic. The State of Iowa has been able to reduce traffic delay constraints through material selection and construction methods to date. Methods for monitoring concrete strength gain and quality have not changed since the first concrete pavements were constructed in Iowa. In 1995, Lee County and the Iowa DOT cooperated in a research project, HR-380, to construct a 7.1 mile (11. 43 km) project to evaluate the use of maturity and pulse velocity nondestructive testing (NDT) methods in the estimation of concrete strength gain. The research identified the pros and cons of each method and suggested an instructional memorandum to utilize maturity measurements to meet traffic delay demands. Maturity was used to reduce the traffic delay opening time from 5-7 days to less than 2 days through the implementation of maturity measurements and special traffic control measures. Recommendations on the development of the maturity curve for each project and the location and monitoring of the maturity thermocouples are included. Examples of equipment that could easily be used by project personnel to estimate the concrete strength using the maturity methods is described.

Minimum Retroreflectivity of Traffic Signs and Pavement Markings, HR-562, 1995

This final report contains two separate reports which describe the retroreflectivity levels of various traffic signs and pavement markings on the Iowa primary road system. The data was collected in the fall/winter of 1994 and given to the Federal Highway Administration in March of 1995. This information is currently being combined with similar information from other jurisdictions across the country for the purpose of determining the impact of mandated minimum retroreflectivity levels. The FHWA will be releasing their report sometime in 1996. In October 1992, Congress mandated (Public Law 102-388) the Secretary of Transportation to revise the Manual of Uniform Traffic Control Devices to include a minimum level of retroreflectivity for pavement markings and traffic signs which shall apply to all roads open to public travel. In 1994, the FHWA initiated research studies to determine the retroreflectivity levels which currently exist for signs and markings in an attempt to develop standards which are reasonable to implement. The Iowa Department of Transportation participated in both of the studies and the final reports are included. After compilation and analysis of the collected retroreflectivity data, the FHWA will propose the new MUTCD standards through the federal rule making process. It is estimated that the actual MUTCD change will occur sometime in late 1997 or early 1998.

Traffic Signal Inventory Project, 2001

The Center for Transportation Research and Education performed a traffic signal inventory study for the Iowa Department of Transportation. The purpose of this study was to determine the level of compliance with the Manual on Uniform Traffic Control Devices (MUTCD) and other industry standards of traffic signals on the state highway system. Signals were randomly selected throughout the State of Iowa. Only signals in cities with a population less than 5,000 were considered. Several intersections need to be addressed immediately to correct clearance timing settings. Red clearance intervals were frequently too short. A handful of intersections had inadequate pedestrian clearance times. Six intersections had at least one yellow clearance interval that did not meet Institute of Transportation Engineers standards. Some of the intersections likely would not meet traffic signal warrants and should be investigated for possible removal. The most common problem found with traffic signals was a lack of maintenance. Many of the signals had at least one of the following problems: burned out lights (signals and/or pedestrian heads), pedestrian lenses in need of replacement, dirty cabinet/missing or poor filter, missing visors, or inoperative pedestrian push buttons. Timing sheets were frequently missing or out of date. Another frequent noncompliance issue was the use of backplates. The MUTCD states that backplates should be used on signals viewed against a bright sky. The majority of signals inventoried did not have backplates on the mast-arm mounted signals. The timing at some intersections could likely be improved by reducing the cycle length. Where there were multiple signals in close proximity rarely was there any attempt at signal coordination. Finally, a number of intersections had equipment that by today’s standards would be considered obsolete.

Maintenance of Traffic for Innovative Geometric Design Work Zones, 2015

Currently there are no guidelines within the Manual on Uniform Traffic Control Devices (MUTCD) on construction phasing and maintenance of traffic (MOT) for retrofit construction and maintenance projects involving innovative geometric designs. The research presented in this report addressed this gap in existing knowledge by investigating the state of the practice of construction phasing and MOT for several types of innovative geometric designs including the roundabout, single point urban interchange (SPUI), diverging diamond interchange (DDI), restricted-crossing left turn (RCUT), median U-turn (MUT), and displaced left turn (DLT). This report provides guidelines for transportation practitioners in developing construction phasing and MOT plans for innovative geometric designs. This report includes MOT Phasing Diagrams to assist in the development of MOT strategies for innovative designs. The MOT Phasing Diagrams were developed through a review of literature, survey, interviews with practitioners, and review of plans from innovative geometric design projects. These diagrams are provided as a tool to assist in improving work zone safety and mobility through construction of projects with innovative geometric designs. The aforementioned synthesis of existing knowledge documented existing practices for these types of designs.

Lentoaseman terminaalirakennuksen energiankäyttö ja sisäilmasto

Diplomityössä tarkasteltiin lentoaseman terminaalirakennuksen energia- ja ainevirtoja sekä sisäilman ominaisuuksia. Esimerkkikohteena oli Helsinki-Vantaan lentoaseman keskiterminaalirakennus, jonka 1. ja 2. rakennusvaiheen ulkovaippa muodosti taserajan. Taseen ulkopuolisista tekijöistä tarkasteltiin jäähdytysenergian tuotantoa ja ulkoilman laatua. Työn yhtenä tavoitteena oli muodostaa rakennukselle energiatase. Taseen avulla saatiin tietoa energian jakautumisesta eri toimintoihin ja löydettiin tekijät, joita suunnittelussa tulee painottaa. Terminaalin lähiympäristössä tutkittiin ulkoilman laatua mittausten avulla. Mittaustietoja käytetään apuna tulevaisuuden ilmanottosuunnittelussa. Työssä tarkasteltiin energia- ja ainevirtoina lämpö-, jäähdytys- ja sähköenergian sekä veden ostoa, tuotantoa ja kulutusta sekä prosessointia. Terminaalin lämpötarpeesta hieman yli puolet katettiin kaukolämmöllä. Loput noin 45 % lämpöenergiasta saatiin ns. ilmaisenergioista. Näistä merkittävimmäksi havaittiin sähkölaitteiden luovuttama lämpömäärä. Lämpöhäviöiden kannalta merkittäviä energiavirtoja olivat ilmanvaihdon ja vuotoilmojen kautta siirtyvät energiavirrat, joiden osuuden todettiin olevan noin 80 % terminaalin kokonaislämpöhäviöistä. Vaipan lämmöneristyskyky ja kyky absorboida auringon säteilyä todettiin hyviksi. Tulevaisuudessa tärkeitä suunnittelunäkökohtia tulevat olemaan ilmanvaihdon ja vuotoilman kautta siirtyvien energiavirtojen hallinta sekä sähköenergian ominaiskulutuksen pienentäminen. Ulkoilma todettiin mittauksin hyvätasoiseksi. Lento- ja maaliikenteen päästöarvot olivat lähellä toisiaan ja selvästi ohjearvoja alemmalla tasolla. Päästöjen sijaintiin vaikuttivat liikennemääriä enemmän tuuliolosuhteet. Tulevaisuudessa tuloilma voidaan johtaa terminaaliin yhtä hyvin joko lento- tai maaliikenteen puolelta.

Present and future methodology for the implementation of decision support systems for traffic management

Real-time predictions are an indispensable requirement for traffic management in order to be able to evaluate the effects of different available strategies or policies. The combination of predicting the state of the network and the evaluation of different traffic management strategies in the short term future allows system managers to anticipate the effects of traffic control strategies ahead of time in order to mitigate the effect of congestion. This paper presents the current framework of decision support systems for traffic management based on short and medium-term predictions and includes some reflections on their likely evolution, based on current scientific research and the evolution of the availability of new types of data and their associated methodologies.

Asociación de la concentración de material particulado en Bogotá con infarto agudo de miocardio

Introducción: la contaminación atmosférica no solo tiene efectos sobre el sistema respiratorio sino también sobre el cardiovascular. El objetivo de este estudio es generar evidencia que permita establecer una asociación entre el infarto agudo del miocardio y la concentración de PM10 en el ambiente como un estudio preliminar para un grupo de pacientes en Bogotá. Metodología: la asociación entre la concentración del material particulado (en este caso PM10 medido en la estación más cercana del lugar reportado por el paciente) y el infarto agudo del miocardio se estableció utilizando el diseño case crossover. Se utilizó información de las historias clínicas de los pacientes con infarto agudo del miocardio que ingresaron al Servicio de Urgencias de la FSFB, y las concentraciones de PM10 medido en la estación más cercana al lugar de inicio de los síntomas de síndrome coronario agudo, reportado por el paciente. Resultados: se encontró que la asociación entre la concentración de PM10 y el diagnóstico de infarto agudo del miocardio es estadísticamente significativa teniendo en cuenta tres momentos de control: 2 horas antes del evento, 24 horas antes del evento y 48 horas antes del evento. Discusión: este estudio sugiere que las altas concentraciones de material particulado en el ambiente son un factor de riesgo para el desarrollo de infarto agudo del miocardio especialmente en personas con enfermedad coronaria subyacente. Con esta investigación se demuestra la importancia de generar acciones que disminuyan la contaminación de la ciudad y de esta forma proteger la salud de las personas.

Relación de los factores laborales e individuales con la carga mental de los trabajadores de una institución minera (2014)

Objetivo: Establecer la relación de los factores laborales e individuales con la carga mental en los trabajadores del área de contratación y titulación minera y los de seguimiento y control en una institución minera durante el año 2014. Materiales y métodos: Estudio de corte transversal en 298 trabajadores que trabajan en una Institución Minera, en la ciudad de Bogotá. La identificación de los factores laborales e individuales relacionados con la carga mental se hizo mediante la aplicación de un cuestionario autodiligenciado utilizando la guía de Estimación de la carga mental de trabajo: método NASA TLX, en el cual se realizó análisis de medidas de tendencia central y se indagó relación a través de la prueba Chi cuadrado de Pearson, usando nivel de significación del 5%, con el programa SPSS 20. Resultados: La población predominante era de género masculino, donde la mayoría de los trabajadores fueron ingenieros pertenecientes al área de seguimiento y control, se evidenció asociación estadísticamente significativa entre la profesión con la percepción de exigencia física (p ≤ 0,001), de igual modo entre área de trabajo con la percepción de exigencia mental (p ≤ 0,001), en la cual se establece que la carga mental y el factor profesional (técnicos) y el factor laboral (área de seguimiento y control), son determinantes para la aparición de fatiga fisiológica y cognitiva, ya que en estos se evidencia mayor exigencia física en los trabajadores técnicos con un 81,40% y en los trabajadores del área de seguimiento y control con un 99,04%. Conclusión: Se encontró una alta exigencia mental, temporal y esfuerzo en los trabajadores y una relación significativa entre la profesión con la percepción de exigencia física, predominando en los técnicos, seguidos de abogados e ingenieros y entre el área de trabajo con la percepción de exigencia mental, siendo mayor en el área de seguimiento y control.