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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.
1

REGENERATING THE RIVER OF LIFE OF THE CITY - IMPROVING THE PEDESTRIANS’ EXPERIENCE ON URBAN STREETS IN TORONTO

Chen, Lin 04 1900 (has links)
Urban streets should be functional as both “path” and “place”, but “street as place” has been overlooked in urban design. The purpose of this thesis is to develop design guidelines for improving pedestrians’ experience on urban streets in Toronto. The study site is Gould Street in downtown Toronto. A preliminary study revealed thermal comfort, safety, social interaction and visual experience as key factors influencing pedestrians’ experience on urban streets. Design guidelines were formulated from literature review to address these key factors on Gould Street. These factors also form the framework for site inventories and analyses. The design concept, “Regenerating the river of life of the city”, is implemented by applying the guidelines to three design solutions. These alternatives were compared to identify their strengths and weaknesses related to the guidelines. Conclusions are drawn regarding the applicability of the guidelines, the limitations of the research and possibilities for future studies.
2

Study of Indicators of Recurrent Congestion on Urban Roadway Network Based on Bus Probes

Chen, Cheng January 2010 (has links)
No description available.
3

Characterization of the urban street network and its emerged phenomena

Kazerani, Aisan January 2010 (has links)
An urban environment can be abstracted in form of a street network in order to be further analysed structurally. The urban street network can be represented in various ways by taking different principles and constraints into account. Therefore the aim of this work is to investigate human behaviour and communication in emerged urban phenomena, namely traffic flow and wayfinding, by structural characterization of an appropriate representation of an urban street network and modifying the conventional methods. / In order to characterize the depicted urban street network, centrality measure and specifically betweenness centrality is utilized. This analysis is then implemented to characterize the studied urban phenomena with respect to their structural, temporal and dynamic properties. In case of studying only the structural properties of the phenomena such as route description or self localization the conventional betweenness centrality is performed. But in case of studying the dynamic and temporal properties of a phenomenon such as traffic flow a modified version of betweenness centrality is proposed which considers dynamic and temporal aspects of human travel behaviour. / Experiments are designed to test the implementation of the suggested methods in the studied urban phenomena. The results of experiments demonstrate the efficiency of the proposed model in characterization of the studied urban phenomena in this thesis and then mention some of the problems and potential areas for future works.
4

Urban street design in modern China : standards, practices and outcomes

Zhang, Yi January 2013 (has links)
This thesis investigates and discusses the current design approaches and development trends of urban streets in China. As the methodological focus, multiple case studies and interviews are used to examine actual street design practice to identify the development policy bias of local governments. Since the 1990s, the great economic achievement in most Chinese cities has evoked significant growth in the number of automobiles, as well as the increasingly serious problems of road casualties and congestion. The traffic-engineering-based design approach which used to be widely adopted and implemented in western countries has dominated the development patterns of urban streets in modern China. The conventional paradigm exclusively focuses on the traffic function in urban streets resulting in morphological changes to the urban circulation environment and keeps on neglecting non-vehicular movement and non-traffic needs. The automobile- dominated urban circulation environment has had negative economic, social and public health impacts. Thus, a paradigm shift which calls for a more inclusive design approach for urban streets which balances functions of place and movement is urgently needed in China. To determine the challenges and opportunities for the new paradigm, this research identifies the cultural, political and technical factors for the traffic-centred design trends and the policy bias. Based on this, policy recommendations and an agenda for revolutionary change for achieving better design practice for urban streets in post-modern China are suggested.
5

Multi-resolution Modeling of Dynamic Signal Control on Urban Streets

Massahi, Aidin 29 July 2017 (has links)
Dynamic signal control provides significant benefits in terms of travel time, travel time reliability, and other performance measures of transportation systems. The goal of this research is to develop and evaluate a methodology to support the planning for operations of dynamic signal control utilizing a multi-resolution analysis approach. The multi-resolution analysis modeling combines analysis, modeling, and simulation (AMS) tools to support the assessment of the impacts of dynamic traffic signal control. Dynamic signal control strategies are effective in relieving congestions during non-typical days, such as those with high demands, incidents with different attributes, and adverse weather conditions. This research recognizes the need to model the impacts of dynamic signal controls for different days representing, different demand and incident levels. Methods are identified to calibrate the utilized tools for the patterns during different days based on demands and incident conditions utilizing combinations of real-world data with different levels of details. A significant challenge addressed in this study is to ensure that the mesoscopic simulation-based dynamic traffic assignment (DTA) models produces turning movement volumes at signalized intersections with sufficient accuracy for the purpose of the analysis. Although, an important aspect when modeling incident responsive signal control is to determine the capacity impacts of incidents considering the interaction between the drop in capacity below demands at the midblock urban street segment location and the upstream and downstream signalized intersection operations. A new model is developed to estimate the drop in capacity at the incident location by considering the downstream signal control queue spillback effects. A second model is developed to estimate the reduction in the upstream intersection capacity due to the drop in capacity at the midblock incident location as estimated by the first model. These developed models are used as part of a mesoscopic simulation-based DTA modeling to set the capacity during incident conditions, when such modeling is used to estimate the diversion during incidents. To supplement the DTA-based analysis, regression models are developed to estimate the diversion rate due to urban street incidents based on real-world data. These regression models are combined with the DTA model to estimate the volume at the incident location and alternative routes. The volumes with different demands and incident levels, resulting from DTA modeling are imported to a microscopic simulation model for more detailed analysis of dynamic signal control. The microscopic model shows that the implementation of special signal plans during incidents and different demand levels can improve mobility measures.
6

Determinants of Bicycle Crashes at Urban Signalised Intersections: Preprint

Schröter, Bettina, Hantschel, Sebastian, Huber, Stefan, Gerike, Regine 02 May 2023 (has links)
Problem Bicycle volumes are increasing in many regions worldwide leading to higher relevance of an in-depth understanding of bicyclist safety mechanisms. Detailed studies on bicyclist safety that consider exposure and distinguish by intersection category and crash types are missing for urban signalised intersections which are of particular relevance for bicyclist safety. Method Based on a comprehensive dataset of motorist and bicyclist volumes and infrastructure characteristics for a sample of 269 signalised intersections in two German cities, we analyse in a top-down approach first bicycle crashes of all types and second bicycle crashes by type including turning, right-of-way and loss-of-control. A combination of descriptive statistics and Accident Prediction Models (APM) are applied in terms of analysis methods. Results Bicycle volumes are relevant for all types of intersections and crashes whereas the effect of motor vehicle volumes differ between these different applications. The separation of bicyclists from motor vehicles in time and space increases their safety but also leads to behavioural adaption and risk compensation. The likelihood of right-ofway crashes even increases with more separation in the signalling scheme. The main predictor for loss-of-control crashes in terms of infrastructure are tram tracks. Summary This study provides insights on relevant determinants of bicycle crashes at urban signalised intersections at several levels of detail. Exposure variables as well as the physical separation of bicyclists from motor vehicles show consistent effects on bicycle crash numbers whereas the effects of signalling differ between crash types. Practical Applications The different types of intersections and crashes follow each specific mechanisms of bicyclist safety. The separation of bicyclists and motorists in time and space are paramount at intersections with high bicycle volumes. Risk compensation such as red light running becomes more important as intersections get smaller and motor vehicle volumes decrease.
7

An Urban Morphological Study on Swedish Cities from a Topological Perspective

Sun, Xiaowei January 2012 (has links)
Streets provide the framework of a city and they are necessary for human life. Some underlying patterns of street networks cannot be directly recognized by people. In this study, topological analysis of urban street networks was adopted to build up new insight into urban morphology. Space syntax, which has been integrated into GIS, was applied for the analysis of spatial configuration, and fifty Swedish cities were chosen as samples to uncover various urban patterns. Street connectivity was the focus of the analysis and axial lines were the main analytical tools. The aim of this study was to hierarchically represent the cities’ streets and classify the sample cities into different types by urban morphology. Street data for Swedish cities were collected from OpenStreetMap. ArcGIS 10, with the Axwoman extension, provided a platform to carry out the topological analysis. Natural roads, axial lines and space syntax parameters were generated automatically with the functions of Axwoman. Hierarchical levels of streets were visually represented and the underlying pattern of each city was gotten from the hierarchical representation. Based on street hierarchy, the fifty sample cities were classified into nine groups, wherein cities of the same group had uniform hierarchical levels. Using the hierarchical pattern of each group’s axial lines, the nine city groups were further reclassified into three types. It was found that, for the street network of most sample cities represented with axial lines, not more than 40% of their streets have connectivity larger than the average value. The hierarchical representation also revealed that streets with high connectivity, which provide greater accessibility, were only minorities in the sample cities. Moreover, minor streets with high connectivity were almost distributed in city centers. In some of the studied cities, axial lines made better representation of the hierarchical patterns of streets, while in others, it did not provide a suitable way of uncovering urban patterns compared to natural roads. A limitation of axial lines manifested in this study was that it chopped curved roads into several segments, thus, disrupting the continuity of streets. In general, axial lines can provide a way to uncover urban patterns. They have meaningful effect to city residents and these patterns can help people gain better understanding of the urban structure. In addition, the hierarchical patterns of streets can be used to model pedestrian and traffic flows, predict crime occurrences, and make spatial plans. The hierarchical representation of streets can also contribute to people’s wayfinding performance.
8

Model za utvrđivanje uticaja izdvojenih nesignalisanih pešačkih prelaza na nivo usluge gradskih saobraćajnica / The influence of an unsignalized midblock crosswalk on the level of service of urban street segments estimating model

Garunović Nemanja 09 October 2020 (has links)
<p>Predmet ove doktorske disertacije su izdvojeni pešački prelazi odnosno njihov uticaj na uslove odvijanja motornog saobraćaja na gradskim saobraćajnicama. Ocenu uslova odvijanja motornog saobraćaja na gradskim saobraćajnicama između ostalog vrši se na osnovu brzine putovanja vozila prolaznog toka na odseku koja je u obrnuto proporcionalna sa vremenom putovanja vozila na odseku gradske saobraćajnice. Povećanje vremena putovanja zavisi od veličine ostvarenih vremenskih gubitaka koji nastaju na izdvojenom pešačkom prelazu. Ključna pretpostavka na kojoj je zasnovana ova doktorska disertacija je da vremenski gubici vozačkih tokova na izdvojenom pešačkom prelazu nastaju usled pojave pešaka (ili grupa pešaka) i kao takvi utiču na smanjenje prosečne brzine putovanja tj. povećanje vremena putovanja vozila na odseku. U skladu sa tim cilj rada je definisanje modela za utvrđivanje vremenskih gubitaka vozila na izdvojenim pešačkim prelazima uz mogućnost implementacije u postojećoj metodologiji za definisanje uslova odvijanja saobraćaja na odsecima gradskih saobraćajnica. U skladu sa definisanim ciljem izvršena je analiza prethodnih relevantnih istraživanja, a zatim i prikupljane podatka o uslovima odvijanja saobraćaja u realnom saobraćajnom toku. Sistematizacijom prikupljenih podataka i primenom odgovarajućih matematičkih i statističkih alata utvrđene su zakonitosti nastanaka vremenskih gubitaka vozačkih tokova koji nastaju na izdvojenom pešačkom prelazu i formiran model za njihov proračun.</p> / <p>The theme of this doctoral thesis is the analysis of the midblock pedestrian crossings influence on traffic conditions on urban street segments. The assessment of motor traffic conditions on urban street segments was carried out on the basis of travel speed of through vehicles. Travel speed of through vehicles for the segment represents the relation between the segment length and segment running time, which implies that running time increase directly affects travel speed decrease. Segment running time greatly depends on the value of the achieved delays which occur on a midblock pedestrian crossing. The key assumption, which this doctoral thesis is based on, is that delays of vehicular flows on midblock pedestrian crossings occur as a consequence of pedestrian (or a group of pedestrians) appearance and that they affect the travel speed of through vehicles decrease, that is, the increase of segment running time. Accordingly, the purpose of this paper is defining the model for determination of vehicular delays on midblock pedestrian crossings, with the possibility of its implementation into the existing methodology for defining traffic conditions on the urban street segments. In accordance with the defined aim within the doctoral thesis, the analysis of previous relevant research studies was carried out, and then the research in a real traffic flow. The systematization of the collected data and the application of the appropriate mathematical and statistical tools enabled how to establish the rules of vehicular flows delays occurrence on midblock pedestrian crossing. On the basis of the established rules and correlation of traffic and geometric characteristics of midblock pedestrian crossings, a model for calculating the value of delays occurring in traffic flows was defined.</p>
9

Network level design for cycling: (Chapter 4 - Advances in Transport Policy and Planning - Cycling Part 1: Supply for cycling)

Gerike, Regine, Weikl, Simone, Koszowski, Caroline, Bogenberger, Klaus 12 July 2022 (has links)
This chapter provides an overview of existing approaches for cycle network planning in research and in practice. First, main requirements for cycle networks are described, which are safety, cohesion, directness, comfort, attractiveness and adaptability. Second, an overview of traditional and emerging data sources for cycle network planning is presented and compared with the initially formulated requirements. Third, two approaches for the multi-modal functional classification of street networks including cycling are introduced, followed by a presentation of specific guidance for developing cycle networks and related academic studies. Three approaches for cycle network design are described. (1) The development of cycle networks based on desire lines and cycle routes connecting relevant origins and destinations as suggested by most guidelines is a suitable basis for cycle network design. (2) It should be combined with data-driven demand-focused approaches in order to optimally adjust the cycle networks with user patterns and preferences. (3) Optimization concepts and network growth strategies help to prioritize investments. The main challenge that is hardly addressed in any of the identified references is the coordination of cycle network development with the other transport modes and street functions. We therefore propose an integrated multi-modal approach for cycle network design, an approach that considers all transport modes, street users, street functions and usages and is also coordinated with street design and space availability.
10

Comparative Analysis of Urban Morphology: Evaluating Space Syntax and Traditional Morphological Methods

Sun, Xiaowei January 2013 (has links)
This thesis examines the urban morphology of fifty cities using spatial syntax analysis. The analysis compares the urban street networks of European, USA, Islamic and East Asian cities. Street connectivity was the main metric and natural roads were the basis for the analysis. The aim of the study was to analyze determine how sensitive space syntax methods are for uncovering the hierarchical patterns of urban street networks and examining their scale-free and small-world properties. Street data was collected from OpenStreetMap. ArcGIS 10 with the Axwoman extension was used to study the hierarchical levels of street networks. Matlab provided the platform to examine the scale-free property of street data. Pajek software was used to measure the small-world behavior. Based on the hierarchical representation, the fifty sample cities were classified into different groups and their scale-free and small-world properties were studied. From a traditionally morphological perspective, it was found that some cities in Europe have a close-knit cellular and organic urban morphology. Cities in the USA exhibit gridiron patterns on the whole. Some Islamic cities have special urban structure with houses grouped around the cul-de-sac lanes. Several of the East Asian cities studied also have grid forms. According to the space syntax analysis, urban street networks that have a connectivity value greater than the average value were less than 40%. The results showed that for most cities, the street connectivity distribution follows a power-law distribution and exhibits scale-free properties. Urban street networks of all sample cities were found to have a small-world property. Space syntax cannot detect all of the morphological patterns recognized in traditional morphological studies. The method can, however, efficiently quantify the spatial configuration of a large sample. Space syntax’s topological and scaling metrics thus provide a way to compare urban street networks. These metrics can thus help classify cities according to their street patterns but also contribute to an understanding of human behavior within and thus the design of urban spaces. For example, an urban street network with a small-world property could have high efficiency for traffic flows at local and global levels and should be considered in further study.

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