Calibration of Flow–Density Relationships on Urban Streets

2005 ◽  
Vol 1934 (1) ◽  
pp. 226-234 ◽  
Author(s):  
Ludovic Leclercq
Keyword(s):  
Urban Areas ◽  
Flow Density ◽  
Traffic Data ◽  
Urban Streets ◽  
Traffic State ◽  
Calibration Methods ◽  
Density Relationship ◽  
Traffic Behavior ◽  
Best Fit ◽  
Selection Of

The aim of this paper is to gather some observations resulting from the study of traffic data in an urban environment (Toulouse, France) rather than on freeways, as is often the case in papers that deal with flow–density relationship calibration. Methods developed for freeway data are studied and new ones are presented to address the specificity of traffic behavior in urban areas. A two-step approach is proposed. First, the data are processed to obtain consistent observations for simulation use. This processing includes the calculation of density from occupancy and space mean speed and the aggregation and the selection of data to make them suitable for equilibrium traffic state representation. Then, a best-fit curve is applied to the selected data to obtain flow–density relationships. Finally, the resulting relationships are studied to highlight the peculiarities of traffic behavior in urban streets.

scholarly journals Traffic State Estimation and Classification on Citywide Scale Using Speed Transition Matrices

2020 ◽  
Vol 12 (18) ◽  
pp. 7278
Author(s):  
Leo Tišljarić ◽  
Tonči Carić ◽  
Borna Abramović ◽  
Tomislav Fratrović
Keyword(s):  
State Estimation ◽  
Urban Areas ◽  
Traffic Management ◽  
Data Representation ◽  
Traffic Data ◽  
Transition Matrices ◽  
Positive Effects ◽  
Traffic State ◽  
Traffic State Estimation ◽  
The City

The rising need for mobility, especially in large urban centers, consequently results in congestion, which leads to increased travel times and pollution. Advanced traffic management systems are being developed to take the advantage of increased mobility positive effects and minimize the negative ones. The first step dealing with congestion in urban areas is the detection of congested areas and the estimation of the congestion level. This paper presents a a method for a traffic state estimation on a citywide scale using the novel traffic data representation, named Speed Transition Matrix (STM). The proposed method uses traffic data to extract the STMs and to estimate the traffic state based on the Center Of Mass (COM) computation for every STM. The COM-based approach enables the simplification of the clustering process and provides increased interpretability of the resulting clusters. Using the proposed method, traffic data is analyzed, and the traffic state is estimated for the most relevant road segments in the City of Zagreb, which is the capital and the largest city in Croatia. The traffic state classification results are validated using the cross-validation method and the domain knowledge data with the resulting accuracy of 97% and 91%, respectively. The results indicate the possible application of the proposed method for the traffic state estimation on macro- and micro-locations in the city area. In the end, the application of STMs for traffic state estimation, traffic management, and anomaly detection is discussed.

Spatial Autocorrelation in the Study of Neighbourhoods towards Smart Cities: Empirical Evidence from Kerman, Iran

2012 ◽  
Vol 9 (2) ◽  
pp. 1
Author(s):  
Asra Hosseini
Keyword(s):  
Spatial Autocorrelation ◽  
Urban Areas ◽  
Smart Cities ◽  
Moran’S I ◽  
Moran's I ◽  
Urban Planner ◽  
Universal Feature ◽  
Autocorrelation Method ◽  
Selection Of

From earliest cities to the present, spatial division into residential zones and neighbourhoods is the universal feature of urban areas. This study explored issue of measuring neighbourhoods through spatial autocorrelation method based on Moran's I index in respect of achieving to best neighbourhoods' model for forming cities smarter. The research carried out by selection of 35 neighbourhoods only within central part of traditional city of Kerman in Iran. The results illustrate, 75% of neighbourhoods' area in the inner city of Kerman had clustered pattern, and it shows reduction in Moran's index is associated with disproportional distribution of density and increasing in Moran's I and Z-score have monotonic relation with more dense areas and clustered pattern. It may be more efficient for urban planner to focus on spatial autocorrelation to foster neighbourhood cohesion rather than emphasis on suburban area. It is recommended characteristics of historic neighbourhoods can be successfully linked to redevelopment plans toward making city smarter, and also people's quality of life can be related to the way that neighbourhoods' patterns are defined. 

scholarly journals An Eco-Friendly Multimodal Route Guidance System for Urban Areas Using Multi-Agent Technology

2021 ◽  
Vol 11 (5) ◽  
pp. 2057
Author(s):  
Abdallah Namoun ◽  
Ali Tufail ◽  
Nikolay Mehandjiev ◽  
Ahmed Alrehaili ◽  
Javad Akhlaghinia ◽  
...  
Keyword(s):  
Traffic Flow ◽  
Urban Areas ◽  
Urban Environments ◽  
Ease Of Use ◽  
Transport Infrastructure ◽  
Guidance System ◽  
Planning System ◽  
Flow Density ◽  
Route Guidance ◽  
Agent Based

The use and coordination of multiple modes of travel efficiently, although beneficial, remains an overarching challenge for urban cities. This paper implements a distributed architecture of an eco-friendly transport guidance system by employing the agent-based paradigm. The paradigm uses software agents to model and represent the complex transport infrastructure of urban environments, including roads, buses, trolleybuses, metros, trams, bicycles, and walking. The system exploits live traffic data (e.g., traffic flow, density, and CO2 emissions) collected from multiple data sources (e.g., road sensors and SCOOT) to provide multimodal route recommendations for travelers through a dedicated application. Moreover, the proposed system empowers the transport management authorities to monitor the traffic flow and conditions of a city in real-time through a dedicated web visualization. We exhibit the advantages of using different types of agents to represent the versatile nature of transport networks and realize the concept of smart transportation. Commuters are supplied with multimodal routes that endeavor to reduce travel times and transport carbon footprint. A technical simulation was executed using various parameters to demonstrate the scalability of our multimodal traffic management architecture. Subsequently, two real user trials were carried out in Nottingham (United Kingdom) and Sofia (Bulgaria) to show the practicality and ease of use of our multimodal travel information system in providing eco-friendly route guidance. Our validation results demonstrate the effectiveness of personalized multimodal route guidance in inducing a positive travel behavior change and the ability of the agent-based route planning system to scale to satisfy the requirements of traffic infrastructure in diverse urban environments.

scholarly journals Effect of Enhanced ADAS Camera Capability on Traffic State Estimation

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 1996
Author(s):  
Hoe Kyoung Kim ◽  
Younshik Chung ◽  
Minjeong Kim
Keyword(s):  
State Estimation ◽  
Traffic Engineering ◽  
Flow Density ◽  
Microscopic Simulation ◽  
Traffic Demand ◽  
Traffic System ◽  
Traffic Conditions ◽  
Traffic State ◽  
Vehicle Identification ◽  
Traffic State Estimation

Traffic flow data, such as flow, density and speed, are crucial for transportation planning and traffic system operation. Recently, a novel traffic state estimating method was proposed using the distance to a leading vehicle measured by an advanced driver assistance system (ADAS) camera. This study examined the effect of an ADAS camera with enhanced capabilities on traffic state estimation using image-based vehicle identification technology. Considering the realistic distance error of the ADAS camera from the field experiment, a microscopic simulation model, VISSIM, was employed with multiple underlying parameters such as the number of lanes, traffic demand, the penetration rate of ADAS vehicles and the spatiotemporal range of the estimation area. Although the enhanced functions of the ADAS camera did not affect the accuracy of the traffic state estimates significantly, the ADAS camera can be used for traffic state estimation. Furthermore, the vehicle identification distance of the ADAS camera and traffic conditions with more lanes did not always ensure better accuracy of the estimates. Instead, it is recommended that transportation planners and traffic engineering practitioners carefully select the relevant parameters and their range to ensure a certain level of accuracy for traffic state estimates that suit their purposes.

Selecting Sanitation Solutions for Peri-urban Areas: A Case Study of Can Tho, Vietnam

2010 ◽  
Vol 5 (4) ◽  
Author(s):  
Naomi Carrard ◽  
Juliet Willetts ◽  
Cynthia Mitchell ◽  
Mick Paddon ◽  
Monique Retamal
Keyword(s):  
Urban Areas ◽  
Cost Effective ◽  
Asset Replacement ◽  
Fit For Purpose ◽  
Infrastructure Investments ◽  
Sanitation Systems ◽  
Can Tho City ◽  
Sustainable Futures ◽  
Sanitation Infrastructure ◽  
Selection Of

In peri-urban areas where infrastructure investments have not yet been made, there is a need to determine the most context-appropriate, fit for purpose and sustainable sanitation solutions. Decision makers must identify the optimal system scale (on the spectrum from centralized to community to cluster scale) and assess the long-term costs and socio-economic/environmental impacts associated with different options. Addressing both cost-effectiveness and sustainability are essential to ensure that institutions and communities are able to continue to bear the costs and management burden of infrastructure operation, maintenance and asset replacement. This paper describes an approach to sanitation planning currently being undertaken as a research study in Can Tho City in southern Vietnam, by the Institute for Sustainable Futures and Can Tho University in collaboration with Can Tho Water Supply and Sewerage Company. The aim of the study is to facilitate selection of the most context-appropriate, fit for purpose, cost effective and sustainable sanitation infrastructure solution. As such, the study compares a range of sanitation alternatives including centralized, decentralized (at household or cluster scale) and resource recovery options. This paper provides an overview of the study and considers aspects of the Can Tho and Vietnamese regulatory, development and institutional context that present drivers and challenges for comparison of options and selection of fit for purpose sanitation systems.

FPGA and ASIC implementation of the algorithm for traffic monitoring in urban areas

2011 ◽  
Vol 59 (2) ◽  
pp. 137-140 ◽  
Author(s):  
S. Szczepański ◽  
M. Wöjcikowski ◽  
B. Pankiewicz ◽  
M. KŁosowski ◽  
R. Żaglewski
Keyword(s):  
Urban Areas ◽  
Traffic Monitoring ◽  
Detection Algorithm ◽  
Frame Rate ◽  
Integrated Sensor ◽  
The Road ◽  
Moving Vehicles ◽  
Direction Of Movement ◽  
Account Due ◽  
Selection Of

FPGA and ASIC implementation of the algorithm for traffic monitoring in urban areas This paper describes the idea and the implementation of the image detection algorithm, that can be used in integrated sensor networks for environment and traffic monitoring in urban areas. The algorithm is dedicated to the extraction of moving vehicles from real-time camera images for the evaluation of traffic parameters, such as the number of vehicles, their direction of movement and their approximate speed. The authors, apart from the careful selection of particular steps of the algorithm towards hardware implementation, also proposed novel improvements, resulting in increasing the robustness and the efficiency. A single, stationary, monochrome camera is used, simple shadow and highlight elimination is performed. The occlusions are not taken into account, due to placing the camera at a location high above the road. The algorithm is designed and implemented in pipelined hardware, therefore high frame-rate efficiency has been achieved. The algorithm has been implemented and tested in FPGA and ASIC.

Closure to “High Density Vehicular Flow-Density Relationship”

1968 ◽  
Vol 94 (2) ◽  
pp. 269-270
Author(s):  
Danilo M. Garcia ◽  
John Hugh Jones
Keyword(s):  
High Density ◽  
Flow Density ◽  
Density Relationship

The City of Oslo in Jan Erik Vold’s Poems

2021 ◽  
Vol 66 (1) ◽  
pp. 219-230
Author(s):  
Raluca-Daniela Duinea
Keyword(s):  
Cultural Identity ◽  
Urban Areas ◽  
Social Criticism ◽  
Capital City ◽  
Urban Landscapes ◽  
Reading Technique ◽  
Social Critical ◽  
The 1960S ◽  
The City ◽  
Selection Of

"The City of Oslo in Jan Erik Vold’s Poems. The aim of this paper is to examine, from a cultural and social perspective, the Norwegian urban areas and everyday situations in Jan Erik Vold’s (b. 1939) poems. Our close-reading technique reveals important social aspects, different places and streets, located in the capital city of Norway, Oslo. These urban poems written by the contemporary Norwegian poet Jan Erik Vold contribute to the reconstruction of a new Norwegian cultural identity as it is reflected in a selection of poems taken from Mor Godhjertas glade versjon. Ja (Mother Goodhearted’s Happy Version. Yes, 1968), followed by the poet’s wanderings in the city of Oslo in En som het Abel Ek (One Named Abel Ek, 1988), and concluding with his bitter social criticism in Elg (Moose, 1989) and IKKE. Skillingstrykk fra nittitallet (Not: Broadsides from the Nineties, 1993). Vold’s urban poems emphasise the transition from nyenkle (new simple), friendly and descriptive poems which present closely the city of Oslo on foot, to short, political and social critical poems from the 90s. Thus, it is of great importance to traverse various urban ‘landscapes’ in different periods of time, beginning with the 1960s, followed by the 80s and the 90s. Keywords: Jan Erik Vold, urban poems, social criticism, Norwegian urban areas, the city of Oslo "

scholarly journals How many species of cladocerans (Crustacea, Branchiopoda) are found in Brazilian Federal District?

2013 ◽  
Vol 24 (4) ◽  
pp. 351-362 ◽  
Author(s):  
Francisco Diogo Rocha Sousa ◽  
Lourdes Maria Abdu Elmoor-Loureiro
Keyword(s):  
Urban Areas ◽  
Aquatic Vegetation ◽  
Federal District ◽  
Water Bodies ◽  
Aquatic Environments ◽  
Number Of Species ◽  
Different Types ◽  
Local Extinctions ◽  
Richness Estimators ◽  
Selection Of

AIM: This study aimed provides a checklist of cladocerans and also an evaluation of richness and species composition in the Federal District, Brazil. METHODS: Checklist of cladocerans was obtained evaluating data from the literature, from taxonomic collection (Elmoor-Loureiro's collection) and from fauna surveys conducted over more than three decades in different types of aquatic environments. RESULTS: The 57 water bodies studied showed 56 species, of which 14 are new records. The number of species contained in the list displayed corresponds to 85% of what was expected for richness estimators. The highest number of species was observed in the lentic water bodies (52), which also presented the specific composition of fauna (R = 0.110; p = 0.016), possibly because there were samples taken among the aquatic vegetation. According to our understanding, some species may be subject to local extinctions because they inhabit water bodies located exclusively in urban areas, which can lead to a decline in richness. CONCLUSION: Thus, the results of this study can assist in monitoring aquatic environments and in selection of new areas for surveys of cladocerans in the Federal District.

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