O modelo veículo seguidor – ou car-following – é o coração dos softwares de simulação microscópica de tráfego. Quando bem calibrados, esses softwares são capazes de replicar a realidade em ambiente controlado. Ainda hoje há uma resistência quanto à calibração do modelo veículo seguidor e, mesmo que muitos trabalhos relatem formas de realizá-la, são escassas as referências na literatura sobre calibração utilizando dados de sistemas ônibus. Este trabalho consiste na elaboração de um método de calibração do modelo veículo seguidor de Gipps, combinado ao modelo de aceleração linear, para a replicação da operação de ônibus em corredores exclusivos. A elaboração do método iniciou com uma revisão dos principais modelos veículo seguidor e uma posterior avaliação dos modelos GHR e de Gipps para manobras típicas de sistemas ônibus. A seguir elaborou-se o procedimento de calibração utilizando coleta de dados por meio de filmagens da operação dos ônibus em corredores e da extração dos dados utilizando uma ferramenta de reconhecimento de imagem. O método das coordenadas retangulares foi utilizado para corrigir a paralaxe. Concomitante às filmagens analisou-se visualmente a ocupação dos ônibus para que as taxas de aceleração e desaceleração dos ônibus pudessem ser diferenciadas conforme o nível de ocupação. A calibração foi realizada através da comparação da distância percorrida pelos veículos ao longo do tempo e as correspondentes modeladas. Os resultados para taxas de aceleração e desaceleração obtidas a partir de dados coletados em Curitiba evidenciam a validade do procedimento. A simplicidade do método desenvolvido é uma característica importante, pois permite a replicação em outros ambientes sem a necessidade de equipamentos sofisticados. / The car-following model is the heart of the traffic simulation software and it is able to replicate real traffic conditions in a controlled environment when properly calibrated. Still today there is resistance on the car-following model calibration and, even though many papers report calibration forms of this model, there are scarce references in the literature about calibration using bus systems data. This work is the development of a method for calibrating the Gipps car-following model, combined with the free linear acceleration model, for replication of buses operation in exclusive lanes. We initiated the method planning with a review of the main car-following model and evaluation of GHR and Gipps for typical bus systems maneuvers. In the next step we developed the calibration procedure using data collection through filming bus operation and drawing out data using a tool for image recognition. We used the rectangular coordinates method to parallax correction. We also visually analyzed the buses occupation simultaneously to filming, so bus acceleration and deceleration rates could be differentiated according to the occupancy level. Calibration was achieved by comparing the vehicle distance traveled over time and corresponding modeled. The results for acceleration and deceleration rates and speed desired values obtained from data collected in Curitiba demonstrate the validity of the procedure. An important feature of this method is the plainness, as it enables replication in other environments without the need for sophisticated equipment.

O modelo veículo seguidor – ou car-following – é o coração dos softwares de simulação microscópica de tráfego. Quando bem calibrados, esses softwares são capazes de replicar a realidade em ambiente controlado. Ainda hoje há uma resistência quanto à calibração do modelo veículo seguidor e, mesmo que muitos trabalhos relatem formas de realizá-la, são escassas as referências na literatura sobre calibração utilizando dados de sistemas ônibus. Este trabalho consiste na elaboração de um método de calibração do modelo veículo seguidor de Gipps, combinado ao modelo de aceleração linear, para a replicação da operação de ônibus em corredores exclusivos. A elaboração do método iniciou com uma revisão dos principais modelos veículo seguidor e uma posterior avaliação dos modelos GHR e de Gipps para manobras típicas de sistemas ônibus. A seguir elaborou-se o procedimento de calibração utilizando coleta de dados por meio de filmagens da operação dos ônibus em corredores e da extração dos dados utilizando uma ferramenta de reconhecimento de imagem. O método das coordenadas retangulares foi utilizado para corrigir a paralaxe. Concomitante às filmagens analisou-se visualmente a ocupação dos ônibus para que as taxas de aceleração e desaceleração dos ônibus pudessem ser diferenciadas conforme o nível de ocupação. A calibração foi realizada através da comparação da distância percorrida pelos veículos ao longo do tempo e as correspondentes modeladas. Os resultados para taxas de aceleração e desaceleração obtidas a partir de dados coletados em Curitiba evidenciam a validade do procedimento. A simplicidade do método desenvolvido é uma característica importante, pois permite a replicação em outros ambientes sem a necessidade de equipamentos sofisticados. / The car-following model is the heart of the traffic simulation software and it is able to replicate real traffic conditions in a controlled environment when properly calibrated. Still today there is resistance on the car-following model calibration and, even though many papers report calibration forms of this model, there are scarce references in the literature about calibration using bus systems data. This work is the development of a method for calibrating the Gipps car-following model, combined with the free linear acceleration model, for replication of buses operation in exclusive lanes. We initiated the method planning with a review of the main car-following model and evaluation of GHR and Gipps for typical bus systems maneuvers. In the next step we developed the calibration procedure using data collection through filming bus operation and drawing out data using a tool for image recognition. We used the rectangular coordinates method to parallax correction. We also visually analyzed the buses occupation simultaneously to filming, so bus acceleration and deceleration rates could be differentiated according to the occupancy level. Calibration was achieved by comparing the vehicle distance traveled over time and corresponding modeled. The results for acceleration and deceleration rates and speed desired values obtained from data collected in Curitiba demonstrate the validity of the procedure. An important feature of this method is the plainness, as it enables replication in other environments without the need for sophisticated equipment.

O modelo veículo seguidor – ou car-following – é o coração dos softwares de simulação microscópica de tráfego. Quando bem calibrados, esses softwares são capazes de replicar a realidade em ambiente controlado. Ainda hoje há uma resistência quanto à calibração do modelo veículo seguidor e, mesmo que muitos trabalhos relatem formas de realizá-la, são escassas as referências na literatura sobre calibração utilizando dados de sistemas ônibus. Este trabalho consiste na elaboração de um método de calibração do modelo veículo seguidor de Gipps, combinado ao modelo de aceleração linear, para a replicação da operação de ônibus em corredores exclusivos. A elaboração do método iniciou com uma revisão dos principais modelos veículo seguidor e uma posterior avaliação dos modelos GHR e de Gipps para manobras típicas de sistemas ônibus. A seguir elaborou-se o procedimento de calibração utilizando coleta de dados por meio de filmagens da operação dos ônibus em corredores e da extração dos dados utilizando uma ferramenta de reconhecimento de imagem. O método das coordenadas retangulares foi utilizado para corrigir a paralaxe. Concomitante às filmagens analisou-se visualmente a ocupação dos ônibus para que as taxas de aceleração e desaceleração dos ônibus pudessem ser diferenciadas conforme o nível de ocupação. A calibração foi realizada através da comparação da distância percorrida pelos veículos ao longo do tempo e as correspondentes modeladas. Os resultados para taxas de aceleração e desaceleração obtidas a partir de dados coletados em Curitiba evidenciam a validade do procedimento. A simplicidade do método desenvolvido é uma característica importante, pois permite a replicação em outros ambientes sem a necessidade de equipamentos sofisticados. / The car-following model is the heart of the traffic simulation software and it is able to replicate real traffic conditions in a controlled environment when properly calibrated. Still today there is resistance on the car-following model calibration and, even though many papers report calibration forms of this model, there are scarce references in the literature about calibration using bus systems data. This work is the development of a method for calibrating the Gipps car-following model, combined with the free linear acceleration model, for replication of buses operation in exclusive lanes. We initiated the method planning with a review of the main car-following model and evaluation of GHR and Gipps for typical bus systems maneuvers. In the next step we developed the calibration procedure using data collection through filming bus operation and drawing out data using a tool for image recognition. We used the rectangular coordinates method to parallax correction. We also visually analyzed the buses occupation simultaneously to filming, so bus acceleration and deceleration rates could be differentiated according to the occupancy level. Calibration was achieved by comparing the vehicle distance traveled over time and corresponding modeled. The results for acceleration and deceleration rates and speed desired values obtained from data collected in Curitiba demonstrate the validity of the procedure. An important feature of this method is the plainness, as it enables replication in other environments without the need for sophisticated equipment.

Kollektivtrafik är en stor del av mångas vardag och en självklar del av staden. Internationellforskning visar att möjligheten för medborgare att delta i kollektivtrafikplaneringen är tämligenlåg. Däremot saknas det kunskap kring hur detta ser ut i Sverige. Syftet med denna studie varatt öka kunskapen kring hur medborgardeltagande kan se ut inom planeringen avkollektivtrafik. Studien syftade även till att skapa en förståelse för hur planering av kollektivtrafiksker i praktiken. För att undersöka detta har en fallstudie av bussprojektet HelsingborgsExpressen iHelsingborg genomförts. Genom en analys av policydokument och intervjuer medtjänstepersoner har det skapats en nyanserad bild av HelsingborgsExpressen samtmedborgardeltagande inom kollektivtrafik.Studien visar att kollektivtrafikplanering utgår från en rationell planeringsmodell som följertydliga planeringsprinciper för att bidra till uppsatta mål. Målet om en ökad andelkollektivtrafikresenärer förekommer ofta inom denna diskurs. Planeringsprocessen förHelsingborgsExpressen har i mångt och mycket liknat detta tillvägagångssätt. Studien visardock att det inom HelsingborgsExpressen till viss del skett en kombination av rationell ochkommunikativ planering. I planeringen genomfördes en dialog på stadsdelen Råå där syftet varatt få reda på hur medborgarna ställde sig till tre olika alternativ för bussens sträckning. Studienvisar också på att en dialog inom kollektivtrafikplanering kan syfta till att informeramedborgare, få tillgång till den lokala kunskapen samt som ett verktyg för en ökad inkluderingav medborgarna. Inom HelsingborgsExpressen framgår det att medborgarnas lokala kunskapär betydelsefull, däremot finns det tvivelaktigheter angående hur kunskapen har använts samtvilken betydelse den har haft i den beslutsfattande processen. / Public transportation is an essential part of many people’s everyday life and a natural segmentof the city. Research outside Sweden shows that the possibility for citizens to participate withinthe planning of public transportation is rather limited. There is a lack of knowledge whetherthis statement applies to a Swedish context or not. The purpose of this study was to contributewith knowledge and understanding to the discourse of citizen participation and the planning ofpublic transportation in Sweden. This has been achieved by a case study of a Bus RapidTransportation project called HelsingborgsExpressen (The Helsingborg Express) in the southernpart of Sweden. A content analysis and interviews with planners has resulted in a nuancedpicture of HelsingborgsExpressen and citizen participation within the public transportationplanning.The study shows that the planning of public transportation is based around a rational planningdiscourse that follows established planning principles and set goals. The goal of a redoubledmarket share for the public transportation occurs frequently within the discourse in question.The planning process for HelsingborgsExpressen is, in many regards, an example of this. Withinthe planning, one opportunity for citizen participation occurred in the district Råå. The purposeof this citizen participation was to let people prioritize amongst three possible routes for the bus.The study also shows that citizen participation within the planning of public transportation canbe used to inform the citizens, access their local knowledge as well as a tool for including thecitizens to a greater extent. Within HelsingborgsExpressen, the study shows that the citizens’local knowledge is valuable, but the question regarding how this local knowledge has been usedin the decision-making process still exists.

The broken ray transform (BRT) is an integral of a function along a union of two rays with a common vertex. Consider an X-ray beam scanning an object of interest. The ray undergoes attenuation and scatters in all directions inside the object. This phenomena may happen repeatedly until the photons either exit the object or are completely absorbed. In our work we assume the single scattering approximation when the intensity of the rays scattered more than once is negligibly small. Among all paths that the scattered rays travel inside the object we pick the one that is a union of two segments with one common scattering point. The intensity of the ray which traveled this path and exited the object can be measured by a collimated detector. The collimated detector is able to measure the intensity of X-rays from the selected direction. The logarithm of such a measurement is the broken ray transform of the attenuation coefficient plus the logarithm of the scattering coefficient at the scattering point (vertex) and a known function of the scattering angle. In this work we consider the reconstruction of X-ray attenuation coefficient distribution in a plane from the measurements on two or three collimated detector arrays. We derive an exact local reconstruction formula for three flat collimated detectors or three curved or pin-hole collimated detectors. We obtain a range condition for the case of three curved or pin-hole detectors and provide a special case of the range condition for three flat detectors. We generalize the reconstruction formula to four and more detectors and find an optimal set of parameters that minimize noise in the reconstruction. We introduce a more accurate scattering model which takes into account energy shifts due to the Compton effect, derive an exact reconstruction formula and develop an iterative reconstruction method for the energy-dependent case. To solve the problem we assume that the radiation source is monoenergetic and the dependence of the attenuation coefficient on energy is linear on an energy interval from the minimal to the maximal scattered energy. %initial radiation energy. We find the parameters of the linear dependence of the attenuation on energy as a function of a point in the reconstruction plane.

No description available.

The city of Curitiba in southern Brazil is considered to be the cradle of the Bus Rapid Transit (BRT) system. Curitiba has a population of around 1.9 million people and has a higher development index than Brazil in general. A master plan approved in the middle of the 1960’s has guided development of the city in a Transit Oriented Development (TOD) direction by zoning for high development densities close to the five BRT trunk lines in so-called structural axes. This thesis aimed at performing a spatiotemporal and statistical analysis of property development in Curitiba, to examine if the BRT system could have been a motivator for property development, and if so, to what extent. Spatial data including for instance a database of building permits, population densities, social housing locations and cost of land were used in the analysis. The analysis was divided into three themes to examine property development from three perspectives; Timing of Development, Density of Development and Social Housing Inclusion. Results for the entire BRT system showed that a greater “time lag” of property development following BRT development also meant that the property in question was located further away from a BRT line, suggesting that areas close to the BRT were popular. The individual lines showed different effects of timing of development, relating to the heterogenic surroundings and the characteristics of the time periods when the BRT was implemented. High development densities are found in the structural corridors, but high population densities are not only found there but also in areas in the South and Southwest parts of Curitiba. These areas coincide with areas of social housing, which historically has been planned in areas not served by the trunk lines of the BRT system. The conclusion of the thesis is that the BRT system certainly has been a motivator for property development, and that TOD planning with thoughtful zoning can be a powerful tool to direct property development. In order to counteract urban segregation, strategies for including social housing in the structural axes must be implemented.

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.

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.

Under de senaste åren har intresset för spårväg ökat i Sverige och flera städer planerar nya spårvägslinjer. Samtidigt har Bus Rapid Transit eller BRT lyfts fram som ett billigare alternativ till spårväg. Lagen om kollektivtrafik innebär att regioner och kommuner delar ansvaret för kollektivtrafiken. De höga kostnaderna som projekten medför innebär att statliga bidrag som Stadsmiljöavtalen eller Sverigeförhandlingen blir viktiga möjliggörare för projektens genomförande. Samarbetet mellan kommuner, regioner och statliga myndigheter leder till en komplex planprocess där mål och riktlinjer på flera olika nivåer måste tas i beaktning. Infrastruktursatsningar på den skalan förväntas inte bara få konsekvenser på kollektivtrafiken och flera olika visioner för staden kopplas till projekten.  Syftet med arbetet är att förstå vilka diskurser som förekommer inom planeringen av spårväg och BRT. Studien ämnar vidare att undersöka hur diskurser inom planeringen lyfts i olika planeringsdokument. För att ta reda på detta användes fallstudie som den övergripande forskningsstrategin, samt dokumentstudie som den huvudsakliga datainsamlingsmetoden. Arbetet grundas teoretiskt i new mobilities paradigm som innebär att transporter studeras i en tvärvetenskaplig kontext och innebär att perspektiv från sociologi, antropologi och geografi integreras i transportstudier. De undersökta fallen är spårvägen i Lund samt HelsingborgsExpressen i Helsingborg. I varje fall valdes tre dokument ut varav ett var en översiktsplan i varje fall. Dokumentens innehåll och språk analyserades via diskursanalys för att kunna dra slutsatser om vilka diskurser som förekom i fallen. Studien visade att samma diskurser förekom i båda fall. De centrala diskurserna bakom spårvägsprojekten var stadsutveckling, miljö, ekonomi och teknologi. Diskurserna får olika mycket utrymme från dokument till dokument. Diskurserna byggs upp över lång tid och varierar i prominens. Studien visar att stadsutvecklingsdiskursen har ökat i betydelse över tid och att ekonomiska faktorer är en viktig bakomliggande orsak till vilket transportslag kommunerna väljer. Det finns stora likheter i vilka diskurser som tas upp i fallen och även i andra europeiska spårvägsprojekt. Detta visar på att diskurserna är globala och främst kopplade till teknologin och projektets mål snarare än den lokala kontexten.