Adaptive Cruise Control (ACC) vehicles have a longer reaction time, and the on-board sensors have a limited detection range that adversely affects the freeway bottleneck capacity. These limitations can cause small speed fluctuations into larger stop-and-go waves at typical freeway bottlenecks. Microsimulation results revealed that flow instability increases with the increase in ACC market penetration for a single lane freeway. The ACC car following model was developed for higher speed ranges only; thus, it could not capture rapid deceleration to lower speeds, let alone complete stops. The algorithm applies collision avoidance and brake relatively late in those instances, which leads to vehicles clustered closer together when at complete stops (or lower speeds). Therefore, the jam density increases with ACC market penetration. Simulation results also represented that no change in capacity was observed with the introduction of ACC vehicles on a freeway without diverging off-ramp and merging on-ramp demand compared to manually driven vehicles. The result is owed to the fact that lane changes and disturbances are not prominent without merging and diverging sections. However, the situation aggravates more for ACC vehicles when there is diverging off-ramp demand and merging on-ramp demand. The effect becomes severe with the increase of ACC market penetration. The field experiments for the fundamental characteristics of traffic flow showed that maximum capacity can be achieved when all the vehicles are operating in ACC mode. However, that maximum flow is unstable, and a minor speed variation can cause severe capacity drop. The jam density is also more in all ACC scenario that might result in rapid queue propagation as the wave speed is larger compared to the mixed driving scenario. / Includes bibliography. / Thesis (MS)--Florida Atlantic University, 2021. / FAU Electronic Theses and Dissertations Collection

Developments in high resolution traffic sensors over the past decades are providing a wealth of empirical speed-flow data. Travel demand models use speed-flow relationships to assign traffic flows to network links. However, speed-flow relationships have not been revalidated against new detailed traffic sensor data. Therefore, it is necessary to revisit speed-flow relationships based on actual measured conditions on network links rather than assuming constant speed-flow relationships over entire highway network systems. Speed-flow relationships have been particularly difficult to calibrate and estimate when traffic volumes approach capacity, i.e. when the v/c ratio approaches one. This thesis empirically evaluates the speed-flow relationships for v/c < 1 using field data. For congested conditions (v/c > 1) a theoretical approach is taken. A new methodology to determine the distribution of the activation of bottlenecks, bottleneck duration, and bottleneck deactivation is proposed. This thesis is a new contribution to understand the stochastic nature of freeway capacity as well as bottleneck duration, activation, and deactivation. Unlike previous research efforts, this thesis studies speed-flow relationships at the lane level and later presents a method to estimate speed-flow relationships at the link level.

No description available.

Every one who has driven on a freeway has observed the phenomenon of lanechanging. This phenomenon is, of course, caused by the desire of most of the drivers not to be in a slow-moving lane. Therefore, the average driver who finds himself in such a lane moves into a neighboring faster lane, usually after a certain time-lag. This time-lag depends on the dynamic characteristics of the vehicle, the availability of acceptable gaps, and the driver risk, which is the value the driver places on the probability of collision during a maneuver, i.e. the higher the perceived probability of collision, the higher the time-lag. Modelling of the lane-changing phenomenon has been the objective of many investigators in the past. As will be shown later in this study, lane-changing is a very important component in highway traffic flow. In this study, a mathematical model to describe the lane-changing behaviour is suggested based on the lane-changing hypothesis that whenever there is a lane-changing maneuver, the average speed of the neighboring lane is faster than the average speed of the current lane. A set of data has been collected by a methodology which involves aerial photographic technique. The collected data are then used to test the validity of the lanechanging hypothesis, to calibrate and validate an existing lane-changing model, and to develop a gap acceptance function for freeway lane-changing maneuvers. / Master of Science

The highway, its promise of freedom and mobility, stands as a source of intrigue in American culture. Yet, the asphalt and dashed lines that cut across the country conceal the contentious history that accompanied interstate highway construction. This dissertation examines the social and spatial meanings of interstate highway plans in the United States at different historical and geographic scales. This account begins in the late 1930's and travels through the mid 1940's where I discuss Norman Bel Geddes's 1939 Worlds Fair Exhibit, "Futurama" and Robert Moses's 1944 Baltimore Arterial Report. This analysis demonstrates how each man inscribed social values into proposed developments within geographic space. From here I move to Baltimore where from 1944 until about 1979, countless proposals called for the construction of an arterial highway that would cut into the heart of the city. By drawing from the archival records left by Movement Against Destruction (MAD), Relocation Action Movement (RAM), and other groups in that fought against roadway plans in Baltimore, I explore how activists lived, understood, and challenged the new social arrangements embedded in the proposed highway system. I introduce the term infrastructural imaginaries to account for how the proposal or construction of spatially embedded systems seeks to transform lived material and geographic arrangements. The concept of infrastructural imaginaries expands upon Sheila Jasanoff and San-Hyun Kim's "sociotechnical imaginaries" to address how proposed futures appropriate spatial environments and how people lived, understood, and conceptualize themselves within these emergent spaces. The framework of infrastructural imaginaries utilizes Henri Lefebvre's conceptual triad of spatial practice, representations of space, and representational space to analyze the dynamic interactions between infrastructure planning, lived experience, and articulations of possible futures. To study the infrastructural imaginary, the immaterial form, provides a fertile space from which to isolate places where systems fail to take hold, where alternative understanding emerge, and where new forms social interaction takes place. / Ph. D. / The interstate highway, its promise of freedom and mobility, stands as a source of intrigue in American culture. Yet, the asphalt and dashed lines that cut across the country conceal the contentious history that accompanied interstate highway construction. Following the passage of the 1956 Federal Aid Interstate Highway Act movements called ‘freeway revolts’ began in cities across the United States. These protests resisted the construction of highways in urban areas. Additionally, these social movements called attention to the planning practices that condemned the houses of low income and minority populations, clear-cut park land, and disrupted the urban fabric. This dissertation examines Baltimore’s ‘freeway revolt’ using archival documents left by the many activist groups who participated in attempting to stop the highway. Rather than presenting a comprehensive history of these events, this dissertation pays attention to how social understandings of geographic space contributed to highway plans, organized activism, and the practices of those who lived under the threat of impending infrastructure.

Nota sobre a qualidade de viagem é uma classificação associada à opinião emitida por um indivíduo em uma escala ordenada de números naturais. Setenta e dois quilômetros de rodovias vicinais próximas a Araraquara, estado de São Paulo, foram submetidos à reconstrução e manutenção durante os anos 2001 e 2003. Sobre estes segmentos de vias existem dados sobre características e estado de componentes de segmentos, e distribuição de notas sobre a qualidade de viagens obtidas a partir de opiniões emitidas por avaliadores, datados de períodos anteriores às ações de manter e reconstruir segmentos nestes quilômetros de vias. Este trabalho resume e discute resultados de uma tese de doutorado cujo objetivo principal foi mostrar que conseqüências de ações para reconstrução e manutenção de rodovias podem ser usadas para prever alterações em nível de qualidade de viagens expressas por relações entre distribuição de notas que expressem opiniões de avaliadores e ocorrências de medidas sobre características de componentes de rodovias. Depois de mantida e reconstruída a rodovia, as novas características de estado de componentes podem ser medidas em campo, e a qualidade de viagem pode ser levantada por opiniões de avaliadores. Os argumentos usados para atingir o objetivo foram obtidos por manuseio e processamento de dados com uso de estatística descritiva e análise de regressão. Espera-se que a informação sobre o comportamento de relações entre notas e medidas físicas possa contribuir para verificar as conseqüências de reconstrução e manutenção de segmentos de via, do ponto de vista de usuários. E também, orientar critérios e métodos que definam prioridades de ações para reconstruir, manter e melhorar a qualidade de viagens em rodovias. / Scores on trip quality is a classification associated to the opinion emitted by an individual in an orderly scale of natural numbers. Seventy two kilometers of close local highways Araraquara, state of Sao Paulo, Brazil, were submitted to reconstruction and maintenance in the years 2001 to 2003. One have some data reporting measures on characteristics and state of segments and distribution of scores on quality of trips obtained from opinions emitted by appraisers and dated from previous periods of maintaining and rebuilding those kilometers of roads. This work summarizes and discusses results of a doctorate thesis whose main objective went to show that consequences of actions for reconstruction and maintenance of highways can be used to foresee alterations in level of quality of expressed trips for relationships among distribution of notes that express appraisers' opinions and occurrences of measures on characteristics of components of highways. After having maintained and rebuilt the highway, the new characteristics of state of components can be measured in field, and the trip quality can be lifted up from other appraisers' opinions. The arguments used to reach the objective were obtained by handling and data processing with use of descriptive statistics and regression analysis. It is waited that the information about the behavior of relationships between notes and physical measures can contribute to verify the reconstruction consequences and maintenance of road segments, of the users' point of view and, also to guide criteria and methods that define priorities of actions to rebuild, to maintain and to improve the quality of trips in highways.

Thesis (M. App. Sc.)--Carleton University, 2004. / Includes bibliographical references (p. 143-156). Also available in electronic format on the Internet.

Nota sobre a qualidade de viagem é uma classificação associada à opinião emitida por um indivíduo em uma escala ordenada de números naturais. Setenta e dois quilômetros de rodovias vicinais próximas a Araraquara, estado de São Paulo, foram submetidos à reconstrução e manutenção durante os anos 2001 e 2003. Sobre estes segmentos de vias existem dados sobre características e estado de componentes de segmentos, e distribuição de notas sobre a qualidade de viagens obtidas a partir de opiniões emitidas por avaliadores, datados de períodos anteriores às ações de manter e reconstruir segmentos nestes quilômetros de vias. Este trabalho resume e discute resultados de uma tese de doutorado cujo objetivo principal foi mostrar que conseqüências de ações para reconstrução e manutenção de rodovias podem ser usadas para prever alterações em nível de qualidade de viagens expressas por relações entre distribuição de notas que expressem opiniões de avaliadores e ocorrências de medidas sobre características de componentes de rodovias. Depois de mantida e reconstruída a rodovia, as novas características de estado de componentes podem ser medidas em campo, e a qualidade de viagem pode ser levantada por opiniões de avaliadores. Os argumentos usados para atingir o objetivo foram obtidos por manuseio e processamento de dados com uso de estatística descritiva e análise de regressão. Espera-se que a informação sobre o comportamento de relações entre notas e medidas físicas possa contribuir para verificar as conseqüências de reconstrução e manutenção de segmentos de via, do ponto de vista de usuários. E também, orientar critérios e métodos que definam prioridades de ações para reconstruir, manter e melhorar a qualidade de viagens em rodovias. / Scores on trip quality is a classification associated to the opinion emitted by an individual in an orderly scale of natural numbers. Seventy two kilometers of close local highways Araraquara, state of Sao Paulo, Brazil, were submitted to reconstruction and maintenance in the years 2001 to 2003. One have some data reporting measures on characteristics and state of segments and distribution of scores on quality of trips obtained from opinions emitted by appraisers and dated from previous periods of maintaining and rebuilding those kilometers of roads. This work summarizes and discusses results of a doctorate thesis whose main objective went to show that consequences of actions for reconstruction and maintenance of highways can be used to foresee alterations in level of quality of expressed trips for relationships among distribution of notes that express appraisers' opinions and occurrences of measures on characteristics of components of highways. After having maintained and rebuilt the highway, the new characteristics of state of components can be measured in field, and the trip quality can be lifted up from other appraisers' opinions. The arguments used to reach the objective were obtained by handling and data processing with use of descriptive statistics and regression analysis. It is waited that the information about the behavior of relationships between notes and physical measures can contribute to verify the reconstruction consequences and maintenance of road segments, of the users' point of view and, also to guide criteria and methods that define priorities of actions to rebuild, to maintain and to improve the quality of trips in highways.

Call number: LD2668 .T4 1966 L675 / Master of Science

In the beginning of the thesis, I summarize the instruments used in spatial planning in the Czech legal system. These instruments contain Czech Building code . 183/2006 Sb. . I discuss how the public can join the process of creating these legal instruments. The first condition in joining these processes is logically for the public to be well informed. Throughout the entire thesis, I compare how the Czech public is informed with the Aarhus Convention. Then I compare how the Czech public is informed and how they manage to join the processes of creating the spatial planning legal instruments in real life.