This thesis intends to demonstrate how capital infrastructure investments can be targeted objectively, using the "Safe Routes to School" (SRTS) program for context. SRTS impacts physical activity, a determinant of childhood obesity by encouraging children’s regular active transportation use. This thesis supports the widespread implementation of SRTS and has developed the "Shelling Model" to objectively identify schools for programming. Accordingly, the "Shelling Model" aims to objectively identify physical and socio-economic environment variables impacting HISD-E middle school neighborhoods’ walkability. The "Shelling Model" is a first step in creating a walkability index for which pedestrian orientation levels can be identified and schools targeted. This model facilitates the identification of variables, providing insight into neighborhood walkability levels. Revealed by statistically significant variables, in combination with Walkscore and Catchment regression models’ respective 45.5 and 13.6 Adjusted R-Square values, the "Shelling" archetype proves a useful tool for investigating the walkability of HISD-E middle school neighborhoods.

This thesis examines the spatial variation in bicycle commuting across New Orleans. It identifies where in the city bicycle commuting is most and least prevalent. It also explores factors that are promoting and discouraging utilitarian bicycling. A review of existing literature on variables found to influence transportation bicycling is conducted, and a survey is disseminated to residents across the city to determine some of the motivations for and obstacles to transportation bicycling locally. Additionally, case studies are compiled pertaining to two neighborhoods falling on opposite ends of the bike-commute spectrum. These include analysis of socio-economic and demographic data; an evaluation of the built environment using maps and field observation; and interviews to assess residents’ attitudes about and experiences with transportation bicycling. In the end, this thesis should be helpful in pinpointing variables influencing bicycle commute rates and in determining the types of policies and investments that may be most effective in encouraging more bicycling in New Orleans and across the country.

Klimatfrågan har kommit i allt större fokus under de senaste decennierna eftersom människor blivit allt mer medvetna om utsläpp av fossila bränslens påverkan på miljön. Globaliseringen skapar även trängsel i trafiken, eftersom det blir ett ökat tryck i de växande städerna. Både i nationella, regionala och lokala planer har frågan tagits upp och även i företags styrdokument är miljöfrågan i fokus.   Resan mellan arbete och bostad är en resa som utförs varje dag och kan planeras i stor utsträckning. Orsaker till människors val av färdsätt är både psykiska och fysiska men även av praktiska skäl. Denna studie riktar sig till fyra större arbetsplatser i Gävle. Gävle kommun, Gävle sjukhus, Högskolan i Gävle samt Lantmäteriet vilka alla har tydliga cykelstråk till och från Gävle centrum. Dessa arbetsplatser ligger inom en radie av två km från Gävle centrum, vilket utgör ett rimligt avstånd för de anställda att använda cykel istället för bil.    Syftet är att komma fram till ett resultat som visar anledningar och beteenden som kan påverkas och förändras till att pendla med cykel istället för att använda bilen. Ett ökat cykelanvändande leder till minskade utsläpp och mindre trängsel i städerna. Det ger även de anställda ett hälsosammare liv i form av daglig motion vilket i sin tur minskar sjukdomar och frånvaro. Det ger en ekonomisk vinst för både företagen och även de anställdas privata ekonomi.   Fyra intervjuer med arbetsgivare och lika många med anställda har genomförts för att ge en djupgående bild av intervjupersonernas åsikter. 405 anställda uppdelat på fyra arbetsplatser har genomfört en webbaserad enkät för att ge en generell bild av de anställdas åsikter. Denna data har sammanställts för att skapa en rekommendation för vad arbetsgivarna kan påverka hos de anställda i deras val av färdmedel.     Resultatet av studien visar att det finns både utrymme för förbättringar med underhåll av cykelvägnätet i Gävle och även i arbetsgivarnas arbete med att tillgodose arbetsplatserna med rätt utrustning. Störst påverkan ligger i att informera och motivera de anställda om fördelarna och förbättra attityden till cykling, eftersom styrdokumenten är övergripande och inte tillräckligt specifika räcker inte informationen i dessa. / The climate issue has come into focus in recent decades, as people have become more aware of the emissions of fossil fuels on the environment. Globalization also creates congestion, because there will be increased pressure in the growing cities. Both in national, regional and local plans, the issue has been raised and even in corporate governance documents comes the environmental issue into focus.   The trip between work and home is performed daily and can be planned extensively. People choose a means of travel for both mental, physical and practical reasons. This study is aimed at four major workplaces in Gävle: Gävle kommun, Gävle Hospital, the University of Gävle and Lantmäteriet. All workplaces have clear cycle routes to and from Gävle’s city center and all are within a radius of two kilometers from the city’s center, which is a reasonable distance for employees to bike rather than drive.   The goal of this study is to identify the reasons and behaviors that influence decisions to commute by bicycle rather than by car. Increased bicycle use leads to lower emissions and less congestion in the cities. It also gives the employees a healthier life in the form of daily exercise, which in turn reduces illness and absence. It provides an economic benefit for both companies, and also the employees' private economy.   Four interviews with employers and an equal number of employees has been implemented to provide an in-depth picture of interviewees' opinions. 405 employees of the four workplaces were asked to complete a web-based survey about commuting behavior and attitudes. This data has been compiled and recommendations developed to guide employers about how they can influence employee´s transportation choice. The results of the study show that there is both room for Gävle to improve the route network maintenance and for employers' to provide the workplace with the right equipment. The greatest impact is to inform and motivate employees about the benefits of cycling. The company policies treat the subject but are too general and employees are not familiar with their contents.

No description available.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 1998. / Includes bibliographical references (p. 181-184) and index. / This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. / This study develops a model of a person's day activity schedule that can be used to forecast urban travel demand. It is motivated by the notion that travel outcomes are part of an activity scheduling decision, and uses discrete choice models to address the basic modeling problem-capturing decision interactions among the many choice dimensions of the immense activity schedule choice set. An integrated system of choice models represents a person's day activity schedule as an activity pattern and a set of tours. A pattern model identifies purposes, priorities and structure of the day's activities and travel. Conditional tour models describe timing, location and access mode of on-tour activities. The system captures trade-offs people consider, when faced with space and time constraints, among patterns that can include at-home and on-tour activities, multiple tours and trip chaining. It captures sensitivity of pattern choice to activity and travel conditions through a measure of expected tour utility arising from the tour models. When travel and activity conditions change, the relative attractiveness of patterns changes because expected tour utility changes differently for different patterns. An empirical implementation of the model system for Portland, Oregon, establishes the feasibility of specifying, estimating and using it for forecasting. Estimation results match a priori expectations of lifestyle effects on activity selection, including those of (a) household structure and role, such as for females with children, (b) capabilities, such as income, and (c) activity commitments, such as usual work levels. / (cont.) They also confirm the significance of activity and travel accessibility in pattern choice. Application of the model with road pricing and other policies demonstrates its lifestyle effects and how it captures pattern shifting-with accompanying travel changes-that goes undetected by more narrowly focused trip-based and tour-based systems. Although the model has not yet been validated in before-and-after prediction studies, this study gives strong evidence of its behavioral soundness, current practicality, potential to generate cost-effective predictions superior to those of the best existing systems, and potential for enhanced implementations as computing technology advances. / by John L. Bowman. / Ph.D.

Let $\Omega\subset\mathbb{R}^n$ be an open and connected subset of $\mathbb{R}^n$. We say that a function $F\colon \Omega-\Omega\to\mathbb{C}$, where $\Omega-\Omega=\{x-y\colon x,y\in\Omega\}$, is positive definite if for any $x_1,\ldots,x_m\in\Omega$ and any $c_1,\ldots,c_m\in \mathbb{C}$ we have that $\sum_{j,k=1}^m F(x_j-x_k)c_j\overline{c_k}\geq 0$. Let $F\colon\Omega-\Omega\to\mathbb{C}$ be a continuous positive definite function. We give necessary and sufficient conditions for $F$ to have an extension to a continuous and positive definite function defined on the entire Euclidean space $\mathbb{R}^n$. The conditions are formulated in terms of strong commutativity of some certain selfadjoint operators defined on a Hilbert space associated to our positive definite function.

The continuing evolution of urban travel patterns and changing policy goals and priorities requires that transportation researchers and practitioners improve their abilities to plan and forecast the demand for travel. Walking and bicycling - the primary forms of active travel - are generating increasing interest for their potential to reduce automobile use, save governmental and consumer costs, and improve personal and social health outcomes. Yet, current transportation planning tools, namely regional travel demand forecasting models, poorly represent these active travel modes, if at all. More broadly, travel models do an incomplete job of representing the decision-making processes involved in travel choices, especially those factors influencing walking and bicycling. In addition to limitations of data and statistical analysis methods, the research upon which modeling tools are based has yet to settle on a comprehensive theory of travel behavior that accounts for complex relationships around a variety of personal, social, and environmental factors. While modeling tools have explained travel primarily through economic theories, contributions from the geography and psychology fields prove promising. A few scholars have attempted to link these travel behavior explanations together, some with a focus on walking and bicycling, but these theories have yet to make a significant impact on travel modeling practice. This thesis presents a unifying interdisciplinary framework for a theory of travel decision-making with applications for travel demand modeling and forecasting and a focus on walking and bicycling. The framework offers a guide for future research examining the complex relationships of activities, built environment factors, demographic and socioeconomic characteristics, attitudes and perceptions, and habit and exploration on individual short-term travel decisions (with considerations of the influence of medium- and long-term travel-related decisions). A key component of the theory is a hierarchy of travel needs hypothesized to be considered by travelers in the course of their decision-making processes. Although developed to account for the factors that particularly influence decisions surrounding walking and bicycling, the framework is postulated to apply to all travel modes and decisions, including frequency, destination, mode, time-of-day, and route. The first section of the thesis reviews theories from the fields of economics, geography, psychology, and travel behavior that have a large influence on the development of the theory of travel decision-making. In the next and largest chapter, the components and relationships in this theory, including the hierarchy of travel needs, are defined and presented with supporting empirical evidence from travel behavior research. This thesis's final section views the theory of travel decision-making through the lens of applicability to travel demand modeling and forecasting. The state of current travel forecasting tools, travel behavior research, data, and analysis methods with respect to each aspect of the theory is reviewed. Research and data needs are identified. In closing, some opportunities for operationalizing the theory in travel demand models and using these transportation planning tools for analyzing walking, cycling, and other policies are hypothesized and discussed. This thesis, and the theory and applications discussed within, contribute to the academic study of travel behavior, the practical modeling of travel demand, and walking and bicycling research and planning.

In recent years research and planning efforts to enhance the conditions and opportunities for active transportation modes have increased significantly; however, these efforts have primarily focused on pedestrians and bicyclists. Skateboarding and other alternative modes of mobility remain an untapped potential for healthy and sustainable travel. This research addresses numerous knowledge gaps in the literature on utilitarian skateboarding under the larger umbrella of active transportation. Analysis of online survey results and semi-structured interviews with skateboarders in Portland, OR provides insight into the motivations and barriers of traveling by skateboard and the demographics and perceptions of skateboard commuters. Like bicyclists and pedestrians, skateboarders value safe, comfortable, and aesthetically pleasing places to travel and are sensitive to surface conditions, distance, and slope. These similarities present a unique opportunity for cities to create facilities that accommodate diverse users. Disaggregating results by the respondents' gender, skill level, and frequency of transportation-oriented skateboarding highlights significant differences in levels of perceived safety and the practicality of utilitarian skateboarding. The findings have implications for the future of active transportation planning which support Elaine Stratford's vision of "generous geographies that allow for more, and playful, mobilities in the city."

Le choix résidentiel s’articule autour d’un certain nombre de contraintes : qu’elles soient internes au ménage ou résultant de la distorsion du marché, ces contraintes modifient fondamentalement l’ensemble de choix des ménages. La première partie de la thèse porte les contraintes que le ménage subit et qui repose sur une de ses caractéristiques. La littérature a étudié en détail la question de la discrimination à l’accès au logement en mettant en évidence un accès limité et tacite aux ménages immigrés, mais aucune étude ne s’est penché sur la mise en évidence d’une potentielle discrimination résidentielle par les prix. Dans cet article, nous étudions les écarts de loyers effectifs entre les français et les immigrés, à l’aide de la décomposition proposée par Oaxaca & Blinder (1973). Nous cherchons à expliquer ces différentiels de loyers en une part imputable à des différences de choix individuels et en une part relevant d'une discrimination sur le marché du logement sur des données de l’enquête logement de 1996. Bien qu’aucune discrimination par les prix ne soit mise clairement en évidence, certains caractéristiques du logement semblent, toutefois, plus onéreuses pour les immigrés. La seconde partie de cette thèse porte sur sur les contraintes internes au ménage. Le travail de cette première partie s’inscrit dans la continuité des travaux effectués sur l’économie de la famille et celle de la prise de décision concernant leur mobilité. La première contrainte que nous présentons est celle de logements qu’occupent les agents avant de se mettre en ménage. La littérature a étudié en profondeur les choix de mobilité résidentielle des couples à travers la plupart des étapes du cycle de vie, sans se pencher sur celui de la mise en ménage. Cela permettrait pourtant de prendre en compte la pluralité des décideurs au sein du ménage. Ce chapitre présente un modèle collectif de mise en ménage, mesurant la probabilité qu’un couple occupe, ensemble, le logement que l’homme occupe seul, celui que la femme occupe seule, par rapport au fait de les refuser tous deux, basé sur un modèle d’estimation logit multinomal. Nous travaillons sur des données de l’enquête nationale logement de 2002 qui nous permet de retracer l’ensemble des parcours de mobilité des deux agents. Nous nous choix du premier logement du couple au sens de son occupation initiale. L’élaboration du modèle théorique, basé sur un modèle de type collectif, où les agents opèrent une négociation, inclue la situation où les deux agents peuvent ne pas être amenés à quitter leur logement dans les points de menace du couple. Nous proposons un enrichissement du modèle où nous faisons valoir le fait que la décision du logement commun peut impliquer une inefficacité dans les décisions futures du couple. Bien que le logement de l’homme semble un choix avéré, l’inégalité salariale entre les hommes et les femmes, ainsi que la différence d’âge au sein du couple semblent influencer significativement le choix des couples. Ensuite, le choix d’un logement, pour un couple, doit prendre en compte les temps de trajet domicile-travail quotidiens. Les agents, ayant un emploi localisé, choisissent un logement qui répond à leurs besoins dans une région dont l’occupation de l’espace est fortement hétérogène et dont l’offre de logement n’est pas distribuée de façon uniforme. L’idée de l’article est de mesurer l’impact des caractéristiques individuelles des agents sur la décision jointe des temps de trajet du ménage, ainsi que la façon dont les agents se répartissent ces déplacements. Les données sur lesquelles nous travaillons sont celles du recensement de la population de 1999, enrichies de données communales et des temps de trajet des agents. Nous mettons en évidence une distinction des comportements hommes/femmes basée sur l’attraction aux pôles d’emplois et à la stabilité de l’emploi. / The residential choice depends to a certain number of constraints: whether internal to the household or resulting from market distortion, these constraints change considerably the choices set of the households. The first part of the thesis is about the internal constraints to the household. The resulting work is a continuation of the work realized on the family economy and that of decision-making depending on their mobility. The first constraint presented is about the discrimination on the prices in the housing market. The literature has studied in detail the question of the discrimination in access to the housing highlighting a restricted and tacit access to the immigrant households, but no study has ever considered the highlighting of a potential residential discrimination by prices. In this article, we study the effective rent differences between French natives and immigrants, using the decomposition proposed by Oaxaca & Blinder (1973). We search to explain theses rent differentials by a part attributable to individual choices differences and another due to a discrimination on the housing market based on the data of the 1996 housing survey. Although no discrimination by price has clearly been shown, however some housing characteristics seem more expensive for immigrants. The second part of the thesis presents two constraints intra-households. The first of that is housing occupied by agents before they merge in order to create a household. The literature has deeply studied the residential mobility choices of couples through most of the stages of the life cycle, without including that of the household formation. However, this would allow taking into account the plurality of decision makers inside the household. This chapter offer a collective model of the household formation, measuring the probability that a couple, together, occupies the dwelling occupied by the man single, the one occupied by the woman single, compared to the fact of refuse them both, based on the estimations of a multinomial logit model. We work on the data housing national survey of 2002 which allow us to trace the totality the mobility paths of two agents. We studie the choice of the first household housing in the sense of its initial occupation. The elaboration of the theoretical model, based on a collective type model, where agents realized a negotiation, including the situation where the two may not have to leave the respective homes, in the couple threat points. We propose an enhanced version of the model where we argue that the decision of the collective housing can implied an inefficiency in the futures couple decisions. Although the man housing seems to be a proven choice, wage inequality between men and women, as well as the age difference within the couple tend to significantly influence the couples choice. Then, the housing choice, for a couple, has to take into account the daily travel time between home and workplace. The agents, having a localized job, choose a housing which meets their needs in a region where space occupation is strongly heterogeneous and housing supply is not uniformly distributed. The idea of this article is to measure the impact of agents individual characteristics on the attached decision of the household travel times, as well as how the agents allocated theses movements. The data are these of the French 1999 census of the population, enhanced with communal data and agents travel times. We show that a distinction can be realized between men and women on the attraction to the employment poles and the job stability.

Bibliography: leaves 213-224.