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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Urban Air Mobility: Demand Estimation and Feasibility Analysis

Rimjha, Mihir 09 February 2022 (has links)
This dissertation comprises multiple studies surrounding demand estimation, feasibility and capacity analysis, and environmental impact of the Urban Air Mobility (UAM) or Advanced Air Mobility (AAM). UAM is a concept aerial transportation mode designed for intracity transport of passengers and cargo utilizing autonomous (or piloted) electric vehicles capable of Vertical Take-Off and Landing (VTOL) from dense and congested areas. While the industry is preparing to introduce this revolutionary mode in urban areas, realizing the scope and understanding the factors affecting the attractiveness of this mode is essential. The success of UAM depends on its operational efficiency and the relative utility it offers to current travelers. The studies presented in this dissertation primarily focus on analyzing urban travelers' current behavior using revealed preference data and estimating the potential UAM demand for different trip purposes in multiple U.S. urban areas. Chapter II presents a methodology to estimate commuter demand for UAM operations in the Northern California region. A mode-choice model is calibrated from the commuter mode-choice behavior observed in the survey data. An integrated demand estimation framework is developed utilizing the calibrated mode-choice model to estimate UAM demand and place vertiports. The feasibility of commuter UAM operations in Northern California is further analyzed through a series of sensitivity analyses. This study was published in Transportation Research Part A: Policy and Practice journal. In an effort to analyze the feasibility of UAM operations in different use cases, demand estimation frameworks are developed to estimate UAM demand in the airport access trips segment. Chapter III and Chapter IV focus on developing the UAM Concept of Operations (ConOps) and demand estimation methodology for airport access trips to Dallas-Fort Worth International Airport (DFW)/Dallas Love Field Airport (DAL) and Los Angeles International Airport (LAX), respectively. Both studies utilize the latest available originating passenger survey data to understand arriving passengers' mode-choice behavior at the airport. Mode-choice conditional logit models are calibrated from the survey data, further used to estimate UAM demand. The former study is published in the AIAA Aviation 2021 Conference proceeding, and the latter is published in ICNS 2021 Conference proceedings. UAM vertiport capacity may be a barrier to the scalability of UAM operations. A heavy concentration of UAM demand is observed in specific areas such as Central Business Districts (CBD) during the spatial analysis of estimated UAM demand. However, vertiport size could be limited due to land availability and high infrastructure costs in CBDs. Therefore, operational efficiency is critical for capturing maximum UAM demand with limited vertiport size. The study included in Chapter V focuses on analyzing factors impacting vertiport capacity. A discrete-event simulation model is developed to simulate a full day of commuter operations at the San Francisco Financial District's busiest vertiport. Besides calculating the capacity of different fundamental vertiport designs, sensitivity analyses are carried to understand the impact of several assumptions such as service time at landing pads, service time at parking stall, charging rate, etc. The study explores the importance of pre-positioning UAM vehicles during the time of imbalance between arrival and departure requests. This study is published in ICNS 2021 Conference proceedings. Community annoyance from aviation noise has often been a reason for limiting commercial operations at several major airports globally. Busy airports are located in urban areas with high population densities where noise levels in nearby communities could govern capacity constraints. Commercial aviation noise is only a concern during landing and take-offs. Hence, the impact is limited to communities close to the airport. However, UAM vehicles would be operated at much lower altitudes and have more frequent taking-off and landing operations. Since the UAM operations would mostly be over dense urban spaces, the noise potential is significantly high. Chapter VI includes a study on preliminary estimation of noise levels from commuter UAM operations in Northern California and the Dallas-Fort Worth region. This study is published in the AIAA Aviation 2021 Conference proceedings. The final chapter in this dissertation explores the impact of airspace restrictions on UAM demand potential in New York City. Integration of UAM operations in the current National Airspace System (NAS) has been recognized as critical in developing the UAM ecosystem. Several pieces of urban airspace are currently controlled by Air Traffic Control (ATC), where commercial operation density is high. Even though the initial operations are expected to be controlled by the current ATC, the extent to which UAM operations would be allowed in the controlled spaces is still unclear. As the UAM system matures and the ecosystem evolves, integrating UAM traffic with other airspace management might relax certain airspace restrictions. Relaxation of airspace restrictions could increase the attractiveness of UAM due to a decrease in travel time/cost and relatively more optimal placement of vertiports. Quantifying the impact of different levels of airspace restrictions requires an integrated framework that can capture utility changes for UAM under different operational ConOps. This analysis uses a calibrated mode-choice model, restriction-sensitive vertiport placement methodology, and demand estimation process. This study has been submitted for ICNS 2022 Conference. / Doctor of Philosophy / Urban Air Mobility (UAM) or Advanced Air Mobility (AAM) are concept transportation modes currently in development. It proposes transporting passengers and cargo in urban areas using all-electric Vertical Take-Off and Landing (eVTOL) vehicles. UAM is a multi-modal concept involving low-altitude aerial transport. The high capital costs involved in developing vehicles and infrastructure suggests the need for meticulous planning and strong strategy development in the rolling out of UAM. Moreover, urban travelers are relatively more sensitive to travel time savings and travel time reliability; therefore, the efficiency of UAM is critical for its success. This dissertation comprises multiple studies surrounding demand estimation, feasibility and capacity analysis, and the environmental impact of UAM. To estimate the potential for UAM, we need first to understand the mode-choice making behavior of urban travelers and then estimate the relative utility UAM could possibly offer. The studies presented in this dissertation primarily focus on analyzing urban travelers' current behavior and estimating the potential UAM demand for different trip purposes in multiple U.S. urban areas. The system planners would need to know the individual or combined effect of various parameters in the system, such as cost of UAM, network size of UAM, etc., on UAM potential. Therefore, sensitivity analyses with respect to UAM demand are performed against various framework parameters. Capacity constraints are not initially considered for potential demand estimation. However, like any other transportation mode, UAM could suffer from capacity issues that can cause operational delays. A simulation study is dedicated to model UAM operations at a vertiport and estimating factors affecting vertiport capacity. After observing the demand potential for certain optimistic scenarios, we realized the possibility of a large number of low-flying vehicles, which could cause annoyance and environmental impacts. Therefore, the following study focuses on developing a noise estimation framework from a full-day of UAM operations and estimating a highly annoyed population in the Bay Area and Dallas-Fort Worth Region. In our studies, modeling restricted airspaces (due to commercial operations at large airports) was always a critical part of the analysis. The urban airspaces are already quite congested in some urban areas, and we assumed that UAM would not operate in the restricted airspaces. The last study in this dissertation focuses on quantifying the impact of different levels of airspace restrictions on UAM demand potential in New York. It would help system planners gauge the level of integration required between the UAM and National Airspace System (NAS).
12

Testing Criterion Validity of Benefit Transfer Using Simulated Data

Prasai, Nilam 11 September 2008 (has links)
The purpose of this thesis is to investigate how the differences between the study and policy sites impact the performance of benefit function transfer. For this purpose, simulated data are created where all information necessary to conduct the benefit function transfer is available. We consider the six cases of difference between the study and policy sites- scale parameter, substitution possibilities, observable characteristics, population preferences, measurement error in variables, and a case of preference heterogeneity at the study site and fixed preferences at the policy site. These cases of difference were considered one at time and their impact on quality of transfer is investigated. RUM model based on reveled preference was used for this analysis. Function estimated at the study site is transferred to the policy site and willingness to pay for five different cases of policy changes are calculated at the study site. The willingness to pay so calculated is compared with true willingness to pay to evaluate the performance of benefit function transfer. When the study and policy site are different only in terms of scale parameter, equality of estimated and true expected WTP is not rejected for 89.7% or more when the sample size is 1000. Similarly, equality of estimated preference coefficients and true preference coefficients is not rejected for 88.8% or more. In this study, we find that benefit transfer performs better only in one direction. When the function is estimated at lower scale and transferred to the policy site with higher scale, the transfer error is less in magnitude than those which are estimated at higher scale and transferred to the policy site with lower scale. This study also finds that transfer error is less when the function from the study site having more site substitutes is transferred to the policy site having less site substitutes whenever there is difference in site substitution possibilities. Transfer error is magnified when measurement error is involved in any of the variables. This study do not suggest function transfer whenever the study site's model is missing one of the important variable at the policy site or whenever the data on variables included in study site's model is not available at the policy site for benefit transfer application. This study also suggests the use of large representative sample with sufficient variation to minimize transfer error in benefit transfer. / Master of Science
13

Personal, interpersonal, and contextual influences on consumer preferences for plug-in electric vehicles: a mixed-method and interdisciplinary approach

Kormos, Christine 02 May 2016 (has links)
Widespread adoption of plug-in electric vehicles (PEVs) can help to achieve deep reductions in global greenhouse gas emissions; however, the degree to which this potential will be realized depends on consumers’ decisions to purchase these vehicles over conventional ones. To provide comprehensive insight into the psychological and contextual influences on consumer vehicle preferences, three studies were performed using a mixed-methods approach. Study 1 employed a survey and stated choice experiment to explore: 1) the explanatory power of the three psychological variables from Ajzen’s (1991; 2005) theory of planned behaviour in predicting PEV purchase intentions among new vehicle buyers from British Columbia, and 2) the influence of hypothetical variations in financial and non-financial incentives on estimated PEV preference, with the goal of informing the design of provincial policy measures. Vehicle preferences were most strongly influenced by purchase price and point-of-sale incentives – with a roughly 4% forecasted increase in PEV new vehicle market share under a $5,000 purchase rebate – as well as by attitudes about PEVs (especially concerning personally-relevant PEV benefits), perceived behavioural control, and social norms. In Study 2, a latent class choice model was used to integrate survey and choice experiment data to characterize consumer classes based on vehicle preferences, demographic characteristics, and psychological variables. Findings revealed profiles of five distinct preference-based segments and demonstrated that the inclusion of psychological covariates can improve the fit of such latent class models. Study 3 extended these findings through a controlled message framing experiment that evaluated the impact of psychological distance on PEV purchase intentions. Results demonstrated that messages emphasizing both personally-relevant and societally-relevant PEV benefits increased related purchase intentions compared to the control group. Taken together, these findings may be useful in the development of PEV policies as well as targeted marketing and communications strategies aimed at supporting a transition to PEVs within Canada. / Graduate / 0451 / 0621 / 0709 / christine.kormos@gmail.com
14

Contrats agro-environnementaux : évaluation et dispositifs innovants en France / Agri-environmental contracts : evaluation and innovative designs in France

Kuhfuss, Laure 20 December 2013 (has links)
Les Mesures agro-environnementales territorialisées (MAEt) ont été introduites en France pour la programmation 2007-2013 de la Politique Agricole Commune (PAC). La perspective de la réforme de la PAC offre l'opportunité de proposer des pistes d'amélioration de ces mesures. Cette thèse évalue dans une première partie ce dispositif MAEt avec une attention particulière portée aux enjeux de lutte contre les pollutions de l'eau d'origine agricole. Nous étudions dans le premier chapitre la décentralisation croissante du dispositif agro-environnemental, le ciblage et l'adaptation aux territoires à enjeux prioritaires. Cette analyse est illustrée par les résultats d'une enquête menée à l'échelle nationale auprès des agriculteurs éligibles et des agents responsables de la mise en œuvre des MAEt, avec deux focus sur l'Eure et Loir et le Languedoc-Roussillon. Ces analyses complémentaires nous permettent d'apporter des éléments d'explication au trop faible taux d'adoption des mesures de réduction d'intrants. Dans le deuxième chapitre nous estimons avec des méthodes économétriques d'évaluation des effets de traitement si ces mesures, basées sur une auto-sélection des participants, permettent effectivement de réduire l'utilisation d'herbicides par les viticulteurs engagés dans la région Languedoc-Roussillon. La seconde partie de la thèse propose deux dispositifs innovants qui pourraient améliorer l'acceptabilité des MAE par les agriculteurs. Nous étudions dans le chapitre 3 l'effet de l'introduction d'une dimension collective dans les contrats, par la méthode de modélisation des choix appliquée au cas des viticulteurs du Languedoc Roussillon. Cette dimension collective se concrétise par un ‘bonus' monétaire versé à chaque viticulteur engagé à condition qu'un objectif de surfaces engagées soit atteint collectivement. Pour finir, nous analysons dans le chapitre 4 la possibilité d'utiliser des appels à projets pour allouer les contrats agro-environnementaux, sur la base de l'expérience pilote menée par l'Agence de l'Eau Artois-Picardie. Ce mécanisme laisse aux agriculteurs la liberté d'adapter le cahier des charges et les montants des mesures en fonction de leur propre consentement à recevoir. / Territorialized agri-environmental measures (MAEt) were introduced in France for the 2007-2013 Common Agricultural Policy program. The forthcoming CAP reform is an opportunity to improve the design of existing agri-environmental schemes. The first part of this thesis assesses this scheme (MAEt), with special attention paid to water pollution issues. In the first chapter we analyse theadvantages and limits of the partial decentralization of decision-making in the setting-up of agrienvironmentalprojects and of improved targeting through the identification of eligible priority areas.This analysis is illustrated by the results of a national survey conducted with eligible farmers andagents in charge of the implementation of the scheme and by two case studies conducted in Eure etLoir and Languedoc-Roussillon. These surveys help us to identify the reasons for the too low adoptionrates of pesticides reduction measures by farmers. In the second chapter, we estimate the impact ofherbicide reduction measures adopted by winegrowers in the Languedoc-Roussillon region using atreatment effects approach. The second part of the thesis proposes two innovative designs aiming atincreasing the acceptability of agri-environmental measures by farmers. In chapter 3 we study theintroduction of a collective dimension in the contracts. This collective dimension relies on a monetary‘bonus’ paid to each farmer who has signed a contract, provided that the proportion of landcollectively enrolled in the agri-environmental scheme reaches a predefined threshold. We finallyanalyse in chapter 4 the possible use of reverse auctions for the allocation of agri-environmentalcontracts, on the basis of the pilot experiment implemented by the Water Agency in Artois-Picardie.This mechanism enables farmers to adapt the practices they commit to and the payment that they receive to their own willingness to accept.
15

Accommodating flexible spatial and social dependency structures in discrete choice models of activity-based travel demand modeling

Sener, Ipek N. 09 November 2010 (has links)
Spatial and social dependence shape human activity-travel pattern decisions and their antecedent choices. Although the transportation literature has long recognized the importance of considering spatial and social dependencies in modeling individuals’ choice behavior, there has been less research on techniques to accommodate these dependencies in discrete choice models, mainly because of the modeling complexities introduced by such interdependencies. The main goal of this dissertation, therefore, is to propose new modeling approaches for accommodating flexible spatial and social dependency structures in discrete choice models within the broader context of activity-based travel demand modeling. The primary objectives of this dissertation research are three-fold. The first objective is to develop a discrete choice modeling methodology that explicitly incorporates spatial dependency (or correlation) across location choice alternatives (whether the choice alternatives are contiguous or non-contiguous). This is achieved by incorporating flexible spatial correlations and patterns using a closed-form Generalized Extreme Value (GEV) structure. The second objective is to propose new approaches to accommodate spatial dependency (or correlation) across observational units for different aspatial discrete choice models, including binary choice and ordered-response choice models. This is achieved by adopting different copula-based methodologies, which offer flexible dependency structures to test for different forms of dependencies. Further, simple and practical approaches are proposed, obviating the need for any kind of simulation machinery and methods for estimation. Finally, the third objective is to formulate an enhanced methodology to capture the social dependency (or correlation) across observational units. In particular, a clustered copula-based approach is formulated to recognize the potential dependence due to cluster effects (such as family-related effects) in an ordered-response context. The proposed approaches are empirically applied in the context of both spatial and aspatial choice situations, including residential location and activity participation choices. In particular, the results show that ignoring spatial and social dependencies, when present, can lead to inconsistent and inefficient parameter estimates that, in turn, can result in misinformed policy actions and recommendations. The approaches proposed in this research are simple, flexible and easy-to-implement, applicable to data sets of any size, do not require any simulation machinery, and do not impose any restrictive assumptions on the dependency structure. / text
16

Two papers on car fleet modeling

Habibi, Shiva January 2013 (has links)
<p>QC 20130524</p>
17

Dynamic Programming Approaches for Estimating and Applying Large-scale Discrete Choice Models

Mai, Anh Tien 12 1900 (has links)
People go through their life making all kinds of decisions, and some of these decisions affect their demand for transportation, for example, their choices of where to live and where to work, how and when to travel and which route to take. Transport related choices are typically time dependent and characterized by large number of alternatives that can be spatially correlated. This thesis deals with models that can be used to analyze and predict discrete choices in large-scale networks. The proposed models and methods are highly relevant for, but not limited to, transport applications. We model decisions as sequences of choices within the dynamic discrete choice framework, also known as parametric Markov decision processes. Such models are known to be difficult to estimate and to apply to make predictions because dynamic programming problems need to be solved in order to compute choice probabilities. In this thesis we show that it is possible to explore the network structure and the flexibility of dynamic programming so that the dynamic discrete choice modeling approach is not only useful to model time dependent choices, but also makes it easier to model large-scale static choices. The thesis consists of seven articles containing a number of models and methods for estimating, applying and testing large-scale discrete choice models. In the following we group the contributions under three themes: route choice modeling, large-scale multivariate extreme value (MEV) model estimation and nonlinear optimization algorithms. Five articles are related to route choice modeling. We propose different dynamic discrete choice models that allow paths to be correlated based on the MEV and mixed logit models. The resulting route choice models become expensive to estimate and we deal with this challenge by proposing innovative methods that allow to reduce the estimation cost. For example, we propose a decomposition method that not only opens up for possibility of mixing, but also speeds up the estimation for simple logit models, which has implications also for traffic simulation. Moreover, we compare the utility maximization and regret minimization decision rules, and we propose a misspecification test for logit-based route choice models. The second theme is related to the estimation of static discrete choice models with large choice sets. We establish that a class of MEV models can be reformulated as dynamic discrete choice models on the networks of correlation structures. These dynamic models can then be estimated quickly using dynamic programming techniques and an efficient nonlinear optimization algorithm. Finally, the third theme focuses on structured quasi-Newton techniques for estimating discrete choice models by maximum likelihood. We examine and adapt switching methods that can be easily integrated into usual optimization algorithms (line search and trust region) to accelerate the estimation process. The proposed dynamic discrete choice models and estimation methods can be used in various discrete choice applications. In the area of big data analytics, models that can deal with large choice sets and sequential choices are important. Our research can therefore be of interest in various demand analysis applications (predictive analytics) or can be integrated with optimization models (prescriptive analytics). Furthermore, our studies indicate the potential of dynamic programming techniques in this context, even for static models, which opens up a variety of future research directions. / Les gens consacrent une importante part de leur existence à prendre diverses décisions, pouvant affecter leur demande en transport, par exemple les choix de lieux d'habitation et de travail, les modes de transport, les heures de départ, le nombre et type de voitures dans le ménage, les itinéraires ... Les choix liés au transport sont généralement fonction du temps et caractérisés par un grand nombre de solutions alternatives qui peuvent être spatialement corrélées. Cette thèse traite de modèles pouvant être utilisés pour analyser et prédire les choix discrets dans les applications liées aux réseaux de grandes tailles. Les modèles et méthodes proposées sont particulièrement pertinents pour les applications en transport, sans toutefois s'y limiter. Nous modélisons les décisions comme des séquences de choix, dans le cadre des choix discrets dynamiques, aussi connus comme processus de décision de Markov paramétriques. Ces modèles sont réputés difficiles à estimer et à appliquer en prédiction, puisque le calcul des probabilités de choix requiert la résolution de problèmes de programmation dynamique. Nous montrons dans cette thèse qu'il est possible d'exploiter la structure du réseau et la flexibilité de la programmation dynamique afin de rendre l'approche de modélisation dynamique en choix discrets non seulement utile pour représenter les choix dépendant du temps, mais également pour modéliser plus facilement des choix statiques au sein d'ensembles de choix de très grande taille. La thèse se compose de sept articles, présentant divers modèles et méthodes d'estimation, leur application ainsi que des expériences numériques sur des modèles de choix discrets de grande taille. Nous regroupons les contributions en trois principales thématiques: modélisation du choix de route, estimation de modèles en valeur extrême multivariée (MEV) de grande taille et algorithmes d'optimisation non-linéaire. Cinq articles sont associés à la modélisation de choix de route. Nous proposons différents modèles de choix discrets dynamiques permettant aux utilités des chemins d'être corrélées, sur base de formulations MEV et logit mixte. Les modèles résultants devenant coûteux à estimer, nous présentons de nouvelles approches permettant de diminuer les efforts de calcul. Nous proposons par exemple une méthode de décomposition qui non seulement ouvre la possibilité d'estimer efficacement des modèles logit mixte, mais également d'accélérer l'estimation de modèles simples comme les modèles logit multinomiaux, ce qui a également des implications en simulation de trafic. De plus, nous comparons les règles de décision basées sur le principe de maximisation d'utilité de celles sur la minimisation du regret pour ce type de modèles. Nous proposons finalement un test statistique sur les erreurs de spécification pour les modèles de choix de route basés sur le logit multinomial. Le second thème porte sur l'estimation de modèles de choix discrets statiques avec de grands ensembles de choix. Nous établissons que certains types de modèles MEV peuvent être reformulés comme des modèles de choix discrets dynamiques, construits sur des réseaux de structure de corrélation. Ces modèles peuvent alors être estimées rapidement en utilisant des techniques de programmation dynamique en combinaison avec un algorithme efficace d'optimisation non-linéaire. La troisième et dernière thématique concerne les algorithmes d'optimisation non-linéaires dans le cadre de l'estimation de modèles complexes de choix discrets par maximum de vraisemblance. Nous examinons et adaptons des méthodes quasi-Newton structurées qui peuvent être facilement intégrées dans des algorithmes d'optimisation usuels (recherche linéaire et région de confiance) afin d'accélérer le processus d'estimation. Les modèles de choix discrets dynamiques et les méthodes d'optimisation proposés peuvent être employés dans diverses applications de choix discrets. Dans le domaine des sciences de données, des modèles qui peuvent traiter de grands ensembles de choix et des ensembles de choix séquentiels sont importants. Nos recherches peuvent dès lors être d'intérêt dans diverses applications d'analyse de la demande (analyse prédictive) ou peuvent être intégrées à des modèles d'optimisation (analyse prescriptive). De plus, nos études mettent en évidence le potentiel des techniques de programmation dynamique dans ce contexte, y compris pour des modèles statiques, ouvrant la voie à de multiples directions de recherche future.
18

Modeling framework for socioeconomic analysis of managed lanes

Khoeini, Sara 08 June 2015 (has links)
Managed lanes are a form of congestion pricing that use occupancy and toll payment requirements to utilize capacity more efficiently. How socio-spatial characteristics impact users’ travel behavior toward managed lanes is the main research question of this study. This research is a case study of the conversion of a High Occupancy Vehicle (HOV) lane to a High Occupancy Toll (HOT) lane, implemented in Atlanta I-85 on 2011. To minimize the cost and maximize the size of the collected data, an innovative and cost-effective modeling framework for socioeconomic analysis of managed lanes has been developed. Instead of surveys, this research is based on the observation of one and a half million license plates, matched to household locations, collected over a two-year study period. Purchased marketing data, which include detailed household socioeconomic characteristics, supplemented the household corridor usage information derived from license plate observations. Generalized linear models have been used to link users’ travel behavior to socioeconomic attributes. Furthermore, GIS raster analysis methods have been utilized to visualize and quantify the impact of the HOV-to-HOT conversion on the corridor commutershed. At the local level, this study conducted a comprehensive socio-spatial analysis of the Atlanta I-85 HOV to HOT conversion. At the general scale, this study enhances managed lanes’ travel demand models with respect to users’ characteristics and introduces a comprehensive modeling framework for the socioeconomic analysis of managed lanes. The methods developed through this research will inform future Traffic and Revenue Studies and help to better predict the socio-spatial characteristics of the target market.
19

Understanding Immigrants' Travel Behavior in Florida: Neighborhood Effects and Behavioral Assimilation

Zaman, Nishat 14 November 2014 (has links)
The goal of this study was to develop Multinomial Logit models for the mode choice behavior of immigrants, with key focuses on neighborhood effects and behavioral assimilation. The first aspect shows the relationship between social network ties and immigrants’ chosen mode of transportation, while the second aspect explores the gradual changes toward alternative mode usage with regard to immigrants’ migrating period in the United States (US). Mode choice models were developed for work, shopping, social, recreational, and other trip purposes to evaluate the impacts of various land use patterns, neighborhood typology, socioeconomic-demographic and immigrant related attributes on individuals’ travel behavior. Estimated coefficients of mode choice determinants were compared between each alternative mode (i.e., high-occupancy vehicle, public transit, and non-motorized transport) with single-occupant vehicles. The model results revealed the significant influence of neighborhood and land use variables on the usage of alternative modes among immigrants. Incorporating these indicators into the demand forecasting process will provide a better understanding of the diverse travel patterns for the unique composition of population groups in Florida.
20

On inverse reinforcement learning and dynamic discrete choice for predicting path choices

Kristensen, Drew 11 1900 (has links)
La modélisation du choix d'itinéraire est un sujet de recherche bien étudié avec des implications, par exemple, pour la planification urbaine et l'analyse des flux d'équilibre du trafic. En raison de l'ampleur des effets que ces problèmes peuvent avoir sur les communautés, il n'est pas surprenant que plusieurs domaines de recherche aient tenté de résoudre le même problème. Les défis viennent cependant de la taille des réseaux eux-mêmes, car les grandes villes peuvent avoir des dizaines de milliers de segments de routes reliés par des dizaines de milliers d'intersections. Ainsi, les approches discutées dans cette thèse se concentreront sur la comparaison des performances entre des modèles de deux domaines différents, l'économétrie et l'apprentissage par renforcement inverse (IRL). Tout d'abord, nous fournissons des informations sur le sujet pour que des chercheurs d'un domaine puissent se familiariser avec l'autre domaine. Dans un deuxième temps, nous décrivons les algorithmes utilisés avec une notation commune, ce qui facilite la compréhension entre les domaines. Enfin, nous comparons les performances des modèles sur des ensembles de données du monde réel, à savoir un ensemble de données couvrant des choix d’itinéraire de cyclistes collectés dans un réseau avec 42 000 liens. Nous rapportons nos résultats pour les deux modèles de l'économétrie que nous discutons, mais nous n'avons pas pu générer les mêmes résultats pour les deux modèles IRL. Cela était principalement dû aux instabilités numériques que nous avons rencontrées avec le code que nous avions modifié pour fonctionner avec nos données. Nous proposons une discussion de ces difficultés parallèlement à la communication de nos résultats. / Route choice modeling is a well-studied topic of research with implications, for example, for city planning and traffic equilibrium flow analysis. Due to the scale of effects these problems can have on communities, it is no surprise that diverse fields have attempted solutions to the same problem. The challenges, however, come with the size of networks themselves, as large cities may have tens of thousands of road segments connected by tens of thousands of intersections. Thus, the approaches discussed in this thesis will be focusing on the performance comparison between models from two different fields, econometrics and inverse reinforcement learning (IRL). First, we provide background on the topic to introduce researchers from one field to become acquainted with the other. Secondly, we describe the algorithms used with a common notation to facilitate this building of understanding between the fields. Lastly, we aim to compare the performance of the models on real-world datasets, namely covering bike route choices collected in a network of 42,000 links. We report our results for the two models from econometrics that we discuss, but were unable to generate the same results for the two IRL models. This was primarily due to numerical instabilities we encountered with the code we had modified to work with our data. We provide a discussion of these difficulties alongside the reporting of our results.

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