Transit agencies include buffer time in their schedules to maintain stable headways and avoid bus bunching. In this work, a real-time holding mechanism is proposed to dispatch buses on a loop-shaped route, solely based on operating conditions in real-time. Holds are applied at the terminal station to minimize the expected variance of bus headways at departure. The bus-dispatching problem is formulated as a stochastic decision process. The optimality equations are derived and structural properties of the optimal policy are inferred by backward induction. The exact optimal holding policy is then found in closed form, as a function of the expected travel time of buses currently running. A simulation assuming stochastic operating conditions and unstable headway dynamics is performed to assess the expected average waiting time of passengers at stations. The proposed control strategy is found to provide lower passenger waiting time and better resiliency than methods recommended in the literature and used in practice.

Multi-combination vehicles (MCVs) in urban areas impact on productivity, safety, infrastructure, congestion and the environment. However, psychological effects of MCVs on other drivers may also influence the positioning of vehicles and congestion. A literature review revealed little information on the psychological effects of heavy vehicles on other road users. This research can be used to quantify some psychological impacts of MCVs. A testing program was undertaken on the Gateway Motorway to observe passenger car behaviour around MCVs in a lateral and longitudinal sense. Video footage was collected on a four lane divided urban motorway section which was level, straight and away from any off/on ramps. It experiences high traffic volumes with a one-way AADT of approximately 33,500. The route is currently designated for B-doubles, which is the most common MCV in urban areas. In a lateral sense, the research showed that passenger car behaviour changes around heavy vehicles (prime mover semi-trailer combination and B-doubles); however, there is no statistical difference in passenger car behaviour around semi-trailers and B-doubles. Longitudinally it was found that, even though passenger cars shy away from B-doubles more than semi-trailers, B-doubles are still more efficient in a spatial sense since they carry more freight. The outcomes of this research indicate that there is no further psychological impact on passenger cars, when travelling around B-doubles compared with semi-trailers. Where the results identified longitudinal behaviour changes, it was still concluded that B-doubles were more efficient at transporting freight when the passenger car equivalent (PCE) per tonne of freight was considered. Tracking ability testing was undertaken in a rural area to determine the lateral spatial requirements of three different MCVs. The rural testing was considered appropriate since parts of the urban network have similar characteristics to rural networks. A model was developed as a part of this project to process the data collected by Haldane (2002), but results could not be relied upon due to poor quality data.

Literature, while perceived as beneficial, is not widely used in the ESL arena. This study set out to investigate proven benefits of using literature in ESL through a review of the current research, at the same time establishing a link between literature and narrative based on `story grammar' which biological determinism claims the human brain is hardwired to use as a language learning tool. Hypothesizing that there would be no correlation between theory regarding the presence and application of literature in ESL as presented in the current research and the practice as found in the prominent ESL course, New Headway, the study set out to identify narrative input in New Headway's Elementary, Intermediate and Advanced Levels and analyzing the way in which narrative is used to teach language skills and communicative competence. Contrary to expectations a surprisingly high level of narrative was found and the narrative was exploited in full accordance with suggestions made in the current research. The findings indicate that the incorporation of narrative in New Headway is a pedagogically informed decision by the authors to exploit the benefits of literature while at the same time catering to a very heterogeneous audience of international ESL learners. Key terms: literature, narrative, story, biological determinism, ESL course books, New Headway / English Studies / M.Ed.

Temps Inter-véhiculaire (TIV) est une variable microscopique fondamentale dans la théorie du trafic, et a été étudié depuis le début du développement de cette théorie, vers 1930. La distribution de probabilité du TIV décrit la répartition des arrivées des véhicules en un point donné et reflète dans une certaine mesure le comportement de conduite. Beaucoup d'applications en ingénierie du trafic viennent de la connaissance fine de cette variable. La thèse a pour but d'approfondir cette connaissance en modélisant la distribution du TIV dans différents contextes selon différents points de vue. Tout d'abord, deux méthodes d'échantillonnage, la méthode de groupement et la méthode de raffinement sont considérées. L'application numérique concerne deux bases de données, celle de la route nationale RN118 et celle de l'autoroute A6. Ensuite, trois types de modèles probabilistes sont analysés et classifiés. Une comparaison exhaustive des modèles et des méthodes d'estimation est réalisée ce qui conduit à considérer que le modèle gamma-GQM est supérieur aux autres modèles en matière de performance statistique et en efficacité de calcul. Différentes procédures d'estimation sont testées, celle qui est proposée et retenue favorise la stabilité des paramètres estimés. Six nouveaux modèles de TIV sont proposés, calibrés, analysés. Mis à part deux modèles de performance inférieure aux autres et au modèle gamma-GQM, quatre modèles sont équivalents voire meilleurs que le modèle gamma-GQM. Pour une raison pratique, le modèle Double Gamma est choisi à côté du modèle gamma-GQM, comme modèle de comparaison, dans toute la modélisation des TIV. Le calibrage des modèles et l'analyse des paramètres des modèles sont menés, à partir des données réelles, en considérant trois dimensions d'étude du trafic: les échelles macroscopique, mésoscopique et microscopique. Une quatrième dimension d'étude des TIV est constituée des facteurs exogènes au trafic. La prise en compte de ces facteurs exogènes, à chaque échelle macroscopique entraîne la distinction de deux types de facteur exogène : « empêchant » et « impulsant». Finalement, différentes approches de validation sont testées. L'approche proposée par « enveloppe des distributions » semble prometteuse pour le futur / Time Headway (TH) is a microscopic variable in traffic flow theories that has been studied since the 1930s. Distribution of this fundamental variable describes the arrival pattern of vehicles in traffic flow, so probabilistic modeling is the main approach to study TH and represent driving behaviour. The applications of the variable in traffic engineering are varied; include capacity calculation, microscopic simulation, traffic safety analysis, etc. This dissertation aims at modeling the TH distribution in different contexts. Firstly, the short-time sampling method and long-time sampling method are applied to obtain TH samples from the two data bases (the RN118 national roadway and the A6 motorway). Then, three probabilistic TH model types are analyzed and classified. An exhaustive comparison between the existing models and between the corresponding estimation methods lead to consider that the gamma-GQM is the best TH model in the literature. An estimation process is also proposed in order to obtain good and stable estimated results of the parameters. After that, the TH probabilistic modeling is developed by six new models. Except for the two ones which are worse, the four other models are statistically equivalent and/or better than the gamma-GQM. For practical reason, the Double Gamma model is selected, as a comparison model, with the gamma-GQM to calibrate all TH samples. Three traffic levels are considered: macroscopic, mesoscopic and microscopic. The effects of exogenous factors are also examined. Examining this factor in each macroscopic variable level leads to distinguish two following factor types: impeding factor and propulsive factor. Finally, different approaches for TH validation are tested. The proposed approach of “envelope of distributions” seems to be promising for future applications

Over the last decade, extensive research efforts have been placed on performance evaluation and the benefits of innovative CV applications. Findings indicate that CV technology can effectively mitigate the safety, mobility, and environmental challenges experienced on transportation networks. Most of research evaluated CV technology through simulation studies. However, a field study provides a more ideal method of assessing CV technology effectiveness. Therefore, a field study to obtain the actual effectiveness of CV technology was warranted, to validate previous findings, and to add to the body of knowledge surrounding this topic. This thesis presents both a field study and simulation evaluation of the effectiveness of CV smartphone technology on a 1.1 mile segment of State Road 121, containing five intersections, in Gainesville, Florida. Field observations were conducted using a CV application, developed by Connected Signals, Inc., that uses a smartphone application, called EnLighten, to communicate intersection information to driver’s smartphone, which serves as a vehicle on-board unit. Traffic operation and safety performance was evaluated using start-up lost time, discharge distribution model, and speed harmonization. Findings show that the CV smartphone technology improved intersection performance with a reduction in start-up lost time of approximately 86%. Additionally, driving safety improved with a reduction in speed variability by nearly 61% between vehicles in a specific lane for a 100% CV penetration rate. Cost analyses of deploying CV smartphone technology indicate that implementation may result in an average total economic cost savings associated with crashes of nearly $6.8 million at the study site, and approximately $5.6 billion statewide. Findings of the simulation evaluation revealed that the CV technology improved performance of intersections operating at a Level of Service (LOS) B or better, compared to lower operating levels. Operational performance improved at intersections operating at a LOS C with a 30% to 60% CV penetration rate.