Overwhelming evidence throughout the literature has shown that bus overhead and maintenance (O&M) costs increase as buses age. This has implications toward a fleet manager's decision of when one should buy, use, or sell buses to minimize total fleet costs. Unfortunately, there are uncertain market conditions associated with bus fleets that cloud the manager's ability to make appropriate decisions. Using integer programming (IP), O&M trends and changing market conditions are integrated into a model to better analyze bus fleets. Due to recent budget constraints of transit agencies, needs for a bus fleet replacement model have arisen. King County in Washington State has supplied cost aggregated data of their New Flyer (NF) and NF hybrid buses. These data have been analyzed to create statistical relationships based on rising O&M costs per mile with age, which are then integrated with the IP model to determine the impact of changing diesel prices, potential carbon dioxide (CO2) emissions costs, uncertain maintenance costs, and bus purchase cost subsidies. The goal is to aid fleet managers to determine the costs of early or delayed suboptimal bus replacement timing and the impacts of market variability on fleet costs and optimal replacement timing. The optimal replacement age for NF and NF hybrid buses based on King County data and current fuel prices of $3.99/gal are 16.7 and 18.3 years, respectively. It has been consistently observed that greater expense is incurred when buses are replaced earlier rather than later from optimal. To minimize total CO2 emissions (including operation and construction emissions), buses should be replaced slightly before the optimal replacement time without considering CO2 emissions. High diesel prices and CO2 emissions had little or no effect, on when buses should be replaced. However, higher maintenance costs reduced the optimal replacement time by almost two years. Although NF hybrid buses have been found to have no economic advantage over conventional buses, this finding may be a consequence of the different costs associated to the different routes operated by hybrid and conventional buses. Due to the lack of detailed King County's route level historical data, a study of the economic competitiveness of NF hybrids against conventional buses is outside the scope of this thesis. If buses are used less with age, the optimal replacement age is reduced. The optimal replacement age also dropped significantly when the Federal Transit Agency's procurement assistance is applied into the model. The procurement assistance can be up to 80% of the capital costs and can be considered a purchase subsidy from the transit agency viewpoint. If purchase subsidies decrease bus purchase prices by 1%, the optimal replacement age drops approximately 1.5%. When the bus purchase price is reduced by 80%, the optimal bus replacement age is less than 12 years, the FTA's minimum replacement age.

In the last years the steady development of autonomous driving technology has enabled the deployment of more mature autonomous vehicles. These vehicles have been applied in several pilot projects worldwide, most commonly in the form of small buses. At the same time, the amount of people traveling in especially urban areas is continuously growing, resulting in more trips in the transportation system. An efficient transportation system is therefore required to serve the growing passenger demand. Autonomous buses (AB) are assumed to have lower operational costs and with that public transport (PT) systems can potentially be designed more efficiently to facilitate the increased demand better. In this study, an AB specific simulation-based optimization framework is proposed which allows analyzing the impacts AB have on line-based PT systems. The thesis focuses on the transition from existing PT systems towards line-based PT systems operated partially or exclusively by AB. Existing work on PT service design is extended so that realistic AB systems can be investigated. This is achieved by (i) using AB specific operator cost formulations, (ii) integrating infrastructure costs required for AB operations, (iii) utilizing a dynamic, stochastic and schedule-based passenger assignment model for the simulation of PT networks and by (iv) formulating a multi-objective optimization problem allowing to investigate the stakeholder-specific impacts of AB. In Paper I the effects of AB, concerning service frequency and vehicle capacity, on fixed-line PT networks are investigated. Among other metrics, the changes are evaluated based on differences in level of service and passenger flow. Additionally, the sequential introduction of AB in existing PT systems is studied. The framework addresses a case study in Kista, Sweden. The study confirmed the initial hypothesis that the deployment of AB leads to an increase in service frequency and a marginal reduction in vehicle capacity. Furthermore, it could be seen that the deployment of AB increases the passenger load on AB lines and that passengers can shift from other PT modes towards the AB services. Paper II incorporates a multi-objective heuristic optimization algorithm in the simulation framework. The study investigates changes in transport network design based on the deployment of AB. The differences in user-focused and operator-focused network design are analyzed and the impact of AB on these is quantified. This study is applied to a case study in Barkarby, Sweden where a full-sized, line-based PT network is designed to exclusively operate AB. Among other findings, we show that the autonomous technology reduces the number of served bus stops and reduces the total PT network size. Additionally, average passenger waiting time can be reduced when deploying AB on user-focused PT networks, which in turn leads to a further reduction of user cost. / De senaste årens framsteg inom autonom körteknik har lett till mer mogna autonoma fordon. Dessa fordon har setts tillämpas i flera pilotprojekt över hela världen, oftast i form av små bussar. Samtidigt växer mängden människor som reser, särskilt i stadsområden, kontinuerligt vilket resulterar i fler resor i transportsystemet. Därför krävs ett effektivt transportsystem för att tillgodose det växande antalet passagerare. Autonoma bussar (AB) antas ha lägre driftskostnader och därmed kan system för kollektivtrafik (public transport, PT) potentiellt utformas mer effektivt för att underlätta den ökade efterfrågan bättre. I denna studie föreslås ett AB-specifikt simuleringsbaserat optimeringsramverk som gör det möjligt att analysera effekterna AB har på linjebaserade PT-system. Avhandlingen fokuserar på övergången från befintliga PT-system till linjebaserade PT-system som delvis eller uteslutande drivs av AB. Befintligt arbete med PT-tjänstdesign utvidgas så att realistiska AB-system kan undersökas. Detta uppnås genom att (i) använda AB-specifika operatörskostnadsformuleringar, (ii) integrera infrastrukturkostnader som krävs för AB-verksamhet, (iii) använda en dynamisk, stokastisk och schemabaserad modell för att tilldela passagerare vid simulering av PT-nät samt genom att (iv) formulera ett multifunktionellt optimeringsproblem som gör det möjligt att undersöka AB: s intressespecifika effekter. I artikel I undersöks effekterna av AB, med avseende på servicefrekvens och fordonskapacitet, på fasta linjer i PT-nät. Förändringar utvärderas bland annat utifrån skillnader i servicenivå och passagerarflöde. Dessutom studeras den sekventiella introduktionen av AB i befintliga PT-system. Det föreslagna ramverket tillämpas på en fallstudie i Kista, Sverige. Studien bekräftade den initiala hypotesen att utplaceringen av AB leder till en ökning av servicefrekvensen och en marginell minskning av fordonens kapacitet. Vidare kunde man se att utplaceringen av AB ökar passagerarbelastningen på AB-linjer och att passagerare kan skifta från andra PT-former mot AB-tjänsterna. Artikel II integrerar en multifunktionell heuristisk optimeringsalgoritm i ramverket för simuleringen. Studien undersöker förändringar i transportnätverkets design baserat på implementeringen av AB. Skillnaderna i användarfokuserad och operatörsfokuserad nätverksdesign analyseras och AB: s inverkan på dessa kvantifieras. Denna studie tillämpas på en fallstudie i Barkarby, Sverige, där ett fullstort linjebaserat PT-nät är utformat för att exklusivt driva AB. Vi visar bland annat att den autonoma tekniken reducerar antalet använda busshållplatser och reducerar den totala PT-nätstorleken. Dessutom kan implementeringen av AB på användarfokuserade PT-nät ytterligare förbättra servicenivån främst genom att minska den genomsnittliga väntetiden per passagerare.

Urbanization has resulted in larger and more densely populated cities, which has intensified the pressure on public transportation systems globally. A consequence of the increased use of public transportation is higher energy consumption and, consequently, increased carbon dioxide emissions. The electrification of bus services has therefore become a central issue in public transportation, leading many to consider switching from fossil-fuel-powered buses to electric buses. Against this background, this study aims to investigate the benefits and challenges that arise in the transition to electric buses for two selected bus operators and a public transport authority. To address this aim, the authors have conducted semi-structured interviews with the aforementioned parties and gathered a theoretical framework based on scientific articles. The study concludes that there are both benefits and challenges with the transition. In the long term, there are economic savings to be made, and the transition to electric buses also contributes to achieving sustainability goals. Among the challenges are managing the limited range of electric buses and the need to procure in a way that distinguishes between traffic operations and charging infrastructure. / Urbaniseringen har resulterat i större och mer tätbefolkade städer, vilket har intensifierat trycket på kollektivtrafiksystemen globalt. En följd av den ökade användningen av kollektivtrafik är högre energiförbrukning och därmed ökade koldioxidutsläpp. Elektrifiering av busstrafiken har därför blivit en central fråga inom kollektivtrafiken, vilket gör att många överväger att byta från fossildrivna bussar till elbussar. Mot bakgrunden syftar studien till att undersöka de fördelar och utmaningar som uppstår vid övergången till elbussar för två utvalda bussoperatörer och en trafikhuvudman. För att besvara syftet har författarna genomfört semistrukturerade intervjuer med ovan nämnda och samlat en teoretisk referensram baserad på vetenskapliga artiklar. Studien drar slutsatsen att det finns både fördelar och utmaningar med övergången. På lång sikt finns ekonomiska besparingar att göra, och övergången till elbussar bidrar också till att uppnå hållbarhetsmålen. Bland utmaningarna finns hanteringen av elbussarnas begränsade räckvidd samt behovet av att upphandla på ett sätt som skiljer mellan trafikdrift och laddinfrastruktur.

The purpose of this study was to evaluate the effectiveness of video monitoring devices (VMDs) in reducing incidents of student misbehavior on middle school buses. It was hypothesized that the presence of VMDs would decrease the frequency of behavioral problems encountered by school bus drivers, decrease the number of discipline referrals issued by the drivers, and improve the drivers’ perception of student behavior. The study utilized an experimental design with random assignment of drivers to treatment and control groups. These groups were formed from a population of 282 drivers who serve ten middle schools for Virginia Beach City Public Schools. In the summer of 1993, through a randomization procedure, VMDs were installed on 100 school buses to form the treatment group. The remaining 182 school buses did not receive installation and were designated as the control group. All drivers maintained a daily log of the number of discipline problems encountered on their routes for three 15-day intervals. Statistical analysis revealed a significantly lower number of problems in the treatment group. Secondary analysis indicated that the use of VMDs was ineffective on morning routes but effective on afternoon routes. Also, there was a significantly lower number of discipline problems in the treatment group regardless of the day of the week. As the drivers established rapport and control, both groups experienced a decline in the number of discipline problems throughout the experiment. The treatment group, however, recorded a significantly lower number of problems during each of the three 15-day intervals. This indicates that the students did not become desensitized to the presence of the VMD’s over the five-month experiment. At the conclusion of the study, drivers in the treatment group rated the behavior of their students more highly than the rating of students by drivers in the control group. A tally of the number of discipline referrals issued by the drivers revealed that the members of the treatment group experienced fewer severe disciplinary problems. Finally, multiple regression indicated that of all independent variables, group membership is the best predictor of a number of behavioral problems, discipline referrals issued, and driver perception of student behavior. / Ed. D.

published_or_final_version / Public Administration / Master / Master of Public Administration

Der Nahverkehr in N’Djamena wird von der Präsenz unzähliger privater Minibus-Anbieter dominiert. Diese bieten jedoch keinen qualitativ hochwertigen Service an. Es existiert in der Stadt keine geeignete Planung für die Haltestellen auf den Verkehrswegen. Die Fahrzeiten sind nicht reguliert. Ebenso gibt es keinen Standardtarif. Der Preis wird verhandelt. Die Mehrheit der Fahrer sind wenig qualifiziert; sie haben keine oder nur für kurze Zeit eine Fahrschule besucht. Außerhalb gelegene Stadtviertel sind verkehrsmäßig wenig erschlossen, was vor allem an der schlechten Qualität der Straßen-Infrastruktur liegt. Diese Situation zeigt, dass der Nahverkehr in N’Djamena nicht zuverlässig ist. In den 1990er Jahren kamen die ersten Motorradtaxis als Antwort auf Mobilitätsprobleme auf. Obwohl sie eine Alternative darstellen, nehmen die Probleme in Verbindung mit der Sicherheit, dem Komfort, dem Preis und der Erreichbarkeit immer wieder zu. In diesem Kontext stellen wir uns folgende Frage: Wie kann man, unter Einbeziehung der verschiedenen beteiligten Akteure, in diesen Sektor eingreifen mit dem Ziel, die Qualität der Transport-Dienstleistungen zu verbessern? In die Organisation des städtischen Verkehrs sind derzeit zahlreiche Akteure involviert, die zueinander direkte und indirekte Beziehungen haben. Sie haben ein mehr oder weniger belastbares Netzwerk geschaffen, welches ihnen ein Verhandeln und einen Austausch untereinander ermöglicht sowie das Fällen von Entscheidungen ermöglicht, um gewisse Probleme zu lösen, vor die ihre Organisation gestellt ist. Mit Hilfe von Interviews, die mit Akteuren vor Ort durchgeführt wurden, soll in dieser Arbeit die Funktionsweise des Transportsystems der Motorradtaxis und Minibusse in N’Djamena analysiert werden. Schwerpunkt der Untersuchung sind dabei das Akteurssystem sowie die Konflikte, die sich aus diesem ableiten lassen. Schlüsselwörter : städtischer Verkehr, Minibusse und Motorradtaxis, Akteurssysteme, N’Djamena (Tschad) / The supply of public transportation in N’Djamena is dominated by the innumerable privates’ enterprises of mini-buses. As a result, they do not offer quality services. The stations, routes and schedules are not fixed. In addition, there is no fixed price in other words, it is bargained. The drivers have more or less undergone no training. Consequently, these mini-buses cannot meet the demand of transport, particularly to the zones of the outskirt quarters. As a result, public transportation in N’Djamena is not reliable. Taxi motorbikes emerged around the end of 1990 as an alternative to transportation solution. Even though taxi motorbikes offer their services to cater for public transportation, some problems such as: lack of safety and comfort, derisory price, the absence of reliability or poor accessibility to some quarters increase. In the light of this, we ask ourselves the following question: how can we help the current actors to improve the quality of public transportation services in N’Djamena? Several actors are currently implicated in the organization of public transportation in N’Djamena. They have direct or indirect contacts with one another. There is a more or less strong network that will enable them negotiate and share ideas so as to make important decisions that would enable them resolve certain problems that are obstacles to their organization. Through interviews conducted and researches carried out on the field of the actors this thesis is meant to analyze the working system of some public transportation actors in N’Djamena. Keynoted: public transport, mini-buses and taxi motorbikes, system of actors, N’Djamena (Chad).

Uma das principais externalidades dos transportes na dimensão urbana é a emissão de poluentes locais e a geração de gases de efeito estufa (GEE). O estudo tem por finalidade quantificar as emissões da frota de ônibus urbano de uma cidade brasileira e propor um mecanismo de mitigação de GEE. Para atingir o objetivo, o estudo apresenta os combustíveis e tecnologias disponíveis no Brasil, e através de uma meta-análise identifica as combinações de combustível e tecnologia que proporcionam a maior redução das emissões de CO, HC, NOx, MP e CO2e. Os resultados da análise mostram que algumas das opções de combustível e tecnologia que apresentam melhor desempenho são: B100 associado ao DPF e SCR, GNV associado ao 3WC, B20 associado ao DPF e SCR, e D15 associado ao DPF e SCR. A seguir, as contribuições dos mecanismos de mitigação de GEE para o setor de transportes são analisadas. O impacto do Mecanismo de Desenvolvimento Limpo (MDL) no setor é limitado, e não há muitas perspectivas de atuação. As Ações de Mitigação Nacionalmente Apropriadas (NAMAs), têm potencial para atuar na redução de GEE, e devem proporcionar apoio financeiro oriundo dos fundos climáticos para as ações implantadas nos países em desenvolvimento. Um estudo de caso foi desenvolvido para avaliar a possibilidade de elaboração de uma NAMA para a renovação da frota de ônibus urbano de uma cidade. Os resultados obtidos na meta-análise foram aplicados para avaliar o combustível e tecnologia que proporcionam maior redução das emissões. Os resultados mostram que a renovação da frota tem potencial de desenvolvimento de uma NAMA, visto que reduz emissões de GEE e proporciona co-benefícios; contudo, deve-se estabelecer um sistema de MRV (Monitorar, Reportar, Verificar) capaz de quantificar as emissões na mitigação. / One of the main externalities from urban transportation is the emission of local pollutants and greenhouse gases (GHG). The study aims to quantify the emissions from the urban bus fleet of a Brazilian city and propose a GHG mitigation mechanism. First, the study presents the fuels and technologies available in Brazil, and through a meta-analysis identifies combinations of fuel and technology that provide the greatest reduction in emissions of CO, HC, NOx, PM and CO2e. Results show the fuel and technology that perform best are: B100 associated with DPF and SCR, CNG associated with 3WC, B20 associated with DPF and SCR, and D15 associated with DPF and SCR. The contribution of GHG mitigation mechanisms for the transport sector was analyzed. The impact of the Clean Development Mechanism (CDM) in the sector is limited, and there are not many perspectives for the future. The Nationally Appropriate Mitigation Actions, named NAMAs, have the potential to act in reducing GHG in transport sector, and should provide financial cooperation through climate funds for implementation of actions in developing countries. A case study was developed to evaluate the possibility of developing a NAMA for the renewal of the fleet of urban buses in a Brazilian city. The results obtained in the meta-analysis were applied to evaluate which fuel and technology provide greater reductions in emission. The results show that the renewal of the fleet has the potential for developing a NAMA, since it reduces greenhouse gas emissions and provide co-benefits; however it requires a serious MRV (Monitor, Report, Verify) capable of quantifying the mitigation of emissions.

El tema de investigación es propuesta de mejora del nivel de servicio del tránsito vehicular de la Av. Huancavelica - tramo Av. 13 de Noviembre y Paseo La Breña en la Ciudad de Huancayo. La contrastación de la hipótesis demuestra que, si existe mejora significativa en el nivel de servicio del tránsito vehicular después de implementar las propuestas asociadas en las intersecciones de la avenida Huancavelica con 13 de Noviembre, Pje. La Merced, Jr. La Merced, Jr. Santa Rosa, Jr. Ayacucho, Jr. Cuzco, Jr. Puno y Paseo la Breña. El trabajo describió el análisis de condición actual de la zona de estudio como: tipos de transporte, condiciones actuales de señalización, esquema geométrico, esquema de giros, esquema de semáforos, conteo vehicular, volúmenes y niveles de servicio que detallan el estado real de cada uno de las intersecciones. Después de obtener los datos se analizó y se evaluó con las propuestas implementadas: La primera propuesta fue en optimizar de ciclos de semáforos, la segunda propuesta fue la no inclusión de transporte de carga pesada y la tercera propuesta fue implementación de buses troncales en remplazo al transporte publico actual. Además de ello se propone implementar olas verdes. Finalmente, se redujo el nivel de servicio de estas intersecciones, pasando de un comportamiento inestable a estable, brindando comodidad al usuario. Asimismo, el tiempo de traslado mejoró en la Avenida Huancavelica desde la Avenida 13 de Noviembre hasta Paseo La Breña y viceversa, exhibiendo una mejora considerable, todo esto debido a la implementación de las propuestas asociadas, que hace que la línea tenga un flujo libre. Para el año actual y una proyección a 5 y 10 años, basándose en el crecimiento vehicular de la Provincia de Huancayo.

In 2009, Cobb County School District (CCSD) and Georgia Institute of Technology (Georgia Tech) received a competitive federal grant to implement an idle and tailpipe emission reduction program in the CCSD bus fleet. The project is designed to reduce school bus idling by installing GPS and idle detection systems in the bus, providing bus dispatchers with a web system to track vehicle activity and idling in real-time, and to automatically shut off the engine when idle thresholds at specific locations are exceeded. A team of Georgia Tech researchers is implementing the anti-idle program and estimating the emissions and fuel savings from the project using approved modeling methods. This thesis presents the results of the emission modeling process, as well as an analysis of baseline school bus idling activity. EPA's MOVES mobile source emission model was used to develop emission rates for school buses for each operating mode, which are defined by the instantaneous vehicle speed, acceleration and scaled tractive power. Local data for Cobb County and Atlanta were collected and input into the MOVES model. The pollutants modeled include carbon dioxide, carbon monoxide, particulate matter (coarse and fine), oxides of nitrogen, and gaseous hydrocarbons. The vehicle activity data collected through the GPS and communications equipment installed in the buses were classified into the operating mode bins for each second of recorded data, and multiplied by the corresponding emission rate to determine the total modal emissions before and after project implementation. Preliminary results suggest that thousands of gallons of diesel fuel and thousands of dollars can be saved with the project, improving overall fleet fuel efficiency by 2%, as well as reducing emissions in some categories by as much as 38%.

Bus Rapid Transit (BRT) is a relatively new mode with a wide range of applications that are still not well understood. Its explosive growth in developing and developed countries has increased its exposure but has led to mostly experimental implementation with mixed results. Therefore, better understanding about the reasons behind BRT implementation success and shortcomings is needed. The objective of this thesis is to evaluate the state of BRT planning under different contexts by assessing how background theory and practical implementation of BRT systems compare. The scope is limited to current a detailed evaluation of 13 case studies in the United States, Canada, Australia, Mexico, Brazil, Colombia, and Ecuador chosen to represent some of the most succesful and established systems in the world. Data was obtaiend from previous research as well as direct reporting from agencies. The evaluation is performed through qualitative and quantitative methods. Qualitative methods classify BRT systems by characteristics and assess the relationship between their implementation and performance using the criteria defined in the literature. Quantitative methods build upon the previous analysis to more precisely assess their performance from both the users' and the transit providers' perspectives. This research found that BRT as a public transit mode has a large room of improvement in terms of design and implementation, since there is a significant variability in performance under similar conditions and a considerable gap between planning best practices and implementation. Also, that planning guidelines are still in an early stage of development and difer in scope and application to a particular context. It also found that its success is not conscribed to developing countries, but that its wide range of applications need to be better adapted to the context they should serve. The findings are significant because they dispel myths about the real potential of BRT and partially identify the reasons behind successes and failures of current systems, such as understimation of implementation times and lack of knowledge about component integration. Further research should approach these issues mainly in two complementary directions. First, it should focus on expanding the case study approach to the newer systems in operation once better data is available. Second,it should further advance the development of theoretical framwork for better operational design based on urban form, as well as an evaluation framework that puts more emphasis on user experience and sustainability. Finally, the findings reinforce that BRT is a distinct mode so that systems that do not meet its criteria should not be named as such.