scholarly journals Underground Roundabouts: Analysis of Several Layouts for A Case Study in Urban Area

2020 ◽  
Vol 14 (1) ◽  
pp. 143-153
Author(s):  
Marco Guerrieri ◽  
Matteo Sartori

Background: Roundabouts eliminate some of the most complex and dangerous aspects of traditional at-grade road intersections. In recent times, novel two-level roundabout layouts have been proposed (i.e. target-roundabout and four-flyover roundabout). Nevertheless, no research on underground roundabouts is available. This paper analyzed the underground roundabout planned in the city of Trento (Italy). Objective: The paper examines an underground roundabout in an urban context, planned with the purpose of alleviating traffic congestion in the city of Trento (Italy). Four different layouts have been studied. Methods and Results: This study was conducted with the help of traffic microsimulation in the AIMSUN environment. The traffic model was calibrated using GEH index. The simulated queues are significantly close to the real queues measured in the year 2020. Conclusion: Underground roundabout can reduce queues, travel times, fuel consumption, air pollutant emissions etc. This particular type of roundabout could be used in urban contexts with a traffic demand and congestion problems comparable to those of the present study.

2021 ◽  
Author(s):  
◽  
Jack J. Jiang

<p>Cycling is a memory of the past for most of us, the lack of support from the authorities on the cycling infrastructure made it difficult to attract people to cycle in the city. Urban sprawl, traffic congestion, car dependency, environmental pollution and public health concerns have pressured cities around the world to consider reintegrating cycling into the urban environment.  Design as a research method was utilised to investigate the effectiveness of design methodology and workflow for cycling infrastructure from an architecture and design perspective. Using Wellington City as a design case study, this research aimed to improve the legibility, usability and the image of cycling as a mode of transport in the city. To achieve this, a customisable graphical design framework and branding strategies were developed to structure and organise the design components within cycling infrastructure. The findings from the iterative design processes were visualised through the appropriate architectural and presentation conventions.  This research provided an unique architectural perspectives on the issues of cycling infrastructure; the results would support the transportation advisers and urban planners to further the development and integration of cycling, as a viable mode of transport, within the city.</p>


2018 ◽  
Vol 1 (6) ◽  
pp. 247-257
Author(s):  
Bang Quoc Ho ◽  
Tam Thoai Nguyen ◽  
Khue Hoang Ngoc Vu

Can Tho City is one the 5th largest city in Vietnam, with hight rate of economic growth and densely populated with 1,251,809 people, butsling traffic activities with 566,593 motobikes and 15,105 cars and hundreds of factories. The air in Can Tho city is polluted by dust and ozone. However, Can Tho city currently does not have a study on the simulation air pollution spread, therefore we do not have an overview on the status of air pollution in order to do not have solutions to limit the increase of pollution status of the city. The purpose of this study is to collect air pollutant emissions from other study. After that, TAPOM model is used to simulate the effects of ozone on the surrounding areas and study the ozone regime in Cantho city. The study results showed that the highest ozone concentration for an hour everage is 196 μg/m3. Compare with national technical regulation about ambient air QCVN 5:2013/BTNMT, ozone concentration is approximately at the allowable limit. The study of ozone regime had identified that VOC sensitive areas are Ninh Kieu district and a part in the south of Binh Thuy district, and NOx sensitive areas are the rested areas of Cantho city. The main cause contributing to increased VOC emission in the central area of the city is motorcycles, NOx emissions in the remaining areas of Cantho city are from the rice production factories. Proposals to protect the air quality in Cantho city are suggested.


2021 ◽  
Author(s):  
◽  
Grace Helen Salisbury Mills

<p>In the aftermath of the 2011 earthquake, a state of polycentric urbanity was thrust upon New Zealand’s second largest city. As the city-centre lay in disrepair, smaller centres started to materialise elsewhere, out of necessity. Transforming former urban peripheries and within existing suburbs into a collective, dispersed alternative to the city centre, these sub-centres prompted a range of morphological, socio-cultural and political transformations, and begged multiple questions: how to imbue these new sub-centres with gravity? How to render them a genuine alternative to the CBD? How do they operate within the wider city? How to cope with the physical and cultural transformations of this shifting urbanscape and prevent them occurring ad lib? Indeed, the success and functioning of the larger urban structure hinges upon a critical, informed response to these sub-centre urban contexts. Yet, with an unrelenting focus on the CBD rebuild - effectively a polycentric denial - little such attention has been granted.  Taking this urban condition as its premise and its provocation, this thesis investigates architecture’s role in the emergent sub-centre. It asks: what can architecture do in these urban contexts; how can architecture act upon the emergent sub-centre in a critical, catalytic fashion? Identifying this volatile condition as both an opportunity for architectural experimentation and a need for critical architectural engagement, this thesis seeks to explore the sub-centre (as an idea and actual urban context) as architecture’s project: its raison d’etre, impetus and aspiration.  These inquiries are tested through design-led research: an initial design question provoking further, broader discursive research (and indeed, seeking broader implications). The first section is a site-specific, design for Sumner, Christchurch. Titled ‘An Agora Anew’; this project - both in conception and outcome - is a speculative response to a specific sub-centre condition. The second section ‘The Sub-centre as Architecture’s Project’ explores the ideas provoked by the design project within a discursive framework. Firstly it identifies the sub-centre as a context in desperate need of architectural attention (why architecture?); secondly, it negotiates a possible agenda for architecture in this context through terms of engagement that are formal, critical and opportunistic (how architecture?): enabling it to take a position on and in the sub-centre. Lastly, a critical exegesis positions the design in regards to the broader discursive debate: critiquing it an architectural project predicated upon the idea of the sub-centre.  The implications of this design-led thesis are twofold: firstly, for architecture’s role in the sub-centre (especially to Christchurch); secondly for the possibilities of architecture’s productive engagement with the city (largely through architectural form), more generally. In a century where radical, new urban contexts (of which the sub-centre is just one) are commonplace, this type of thinking – what can architecture do in the city? - is imperative.</p>


2022 ◽  
pp. 1220-1237
Author(s):  
Angel Bartolomé Muñoz de Luna ◽  
Olga Kolotouchkina

The disruptive growth of new information technologies is transforming the dynamics of citizen communication and engagement in the urban context. In order to create new, smart, inclusive, and transparent urban environments, the city governments of London and Madrid have implemented a series of innovative digital applications and citizen communication channels. Through a case study approach, this research assesses the best practices in the field of digital communication and citizen engagement implemented by London and Madrid, with a particular focus on the profile, content, and functions of these new channels. The results of this research are intended to identify relevant new dynamics of interaction and value co-creation for cities and their residents.


2018 ◽  
Vol 12 (8) ◽  
pp. 59
Author(s):  
Santiago Cardona ◽  
Diego Escobar ◽  
Carlos Moncada

The transport models have taken great relevance in the last decades because they help to make big urban planning decisions. In this sense, supply models, such as global average accessibility, seek to approach more and more to reality in order to represent it in the best possible way. In this research article, we compare the different penalties for turns used in the global average accessibility models in the city of Manizales, being compared with the preliminary results of a research thesis in which the penalties for turns were calculated by means of an empirical methodology that analyzes different road intersections in the city. At the end, the savings gradient method is used to measure the differences between the different calculated scenarios.


Author(s):  
Xiao Liang ◽  
Gonçalo Homem de Almeida Correia ◽  
Bart van Arem

This paper proposes a method of assigning trips to automated taxis (ATs) and designing the routes of those vehicles in an urban road network, and also considering the traffic congestion caused by this dynamic responsive service. The system is envisioned to provide a seamless door-to-door service within a city area for all passenger origins and destinations. An integer programming model is proposed to define the routing of the vehicles according to a profit maximization function, depending on the dynamic travel times, which varies with the ATs’ flow. This will be especially important when the number of automated vehicles (AVs) circulating on the roads is high enough that their routing will cause delays. This system should be able to serve not only the reserved travel requests, but also some real-time requests. A rolling horizon scheme is used to divide one day into several periods in which both the real-time and the booked demand will be considered together. The model was applied to the real size case study city of Delft, the Netherlands. The results allow assessing of the impact of the ATs movements on traffic congestion and the profitability of the system. From this case-study, it is possible to conclude that taking into account the effect of the vehicle flows on travel time leads to changes in the system profit, the satisfied percentage and the driving distance of the vehicles, which highlights the importance of this type of model in the assessment of the operational effects of ATs in the future.


2017 ◽  
Vol 171 ◽  
pp. 155-164 ◽  
Author(s):  
Yanan Guan ◽  
Guanyi Chen ◽  
Zhanjun Cheng ◽  
Beibei Yan ◽  
Li'an Hou

2017 ◽  
Vol 26 (2) ◽  
pp. 70-86
Author(s):  
Abdulhaq Hadi Abed Ali

The main objective of this research is to select the best site for the establishment of  a new bridge on the Al Gharraf river within the limits of the Al Muwaffaqiyah region . Al Muwaffaqiyah region is located in Wasit province in Iraq. The study area is divided into multiple zones . Three alternatives are proposed to construct the bridge site. The best one is selected using network analyst tool of ArcGIS software depending on the largest number of routes passing between zones. The route link between both sides of Al Gharraf river in Al Muwaffaqiyah region is one of the important projects in the city. The project will provide a new crossing point on Al Gharraf river . The proposed route will contribute to reduce traffic congestion depending on the foundations of planning and traffic so that gives the desired result of this project in terms of the location and importance of economic feasibility.


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