scholarly journals EFFECTS OF THE RAINSTORM ON URBAN ROAD TRAFFIC SPEED — A CASE STUDY OF SHENZHEN, CHINA

2017 ◽  
Vol XLII-2/W7 ◽  
pp. 71-75 ◽  
Author(s):  
Q. Li ◽  
X. Hao ◽  
W. Wang ◽  
A. Wu ◽  
Z. Xie
Keyword(s):  
Traffic Management ◽  
Road Traffic ◽  
Urban Traffic ◽  
Gps Tracking ◽  
Shenzhen City ◽  
Adverse Weather ◽  
Stormy Weather ◽  
Wide Scale ◽  
Traffic Speed ◽  
The Impact

The adverse weather may significantly impact urban traffic speed and travel time. Understanding the influence of the rainstorm to urban traffic speed is of great importance for traffic management under stormy weather. This study aims to investigate the impact of rainfall intensity on traffic speed in the Shenzhen (China) during the period 1 July 2015–31 August 2016. The analysis was carried out for five 1-h periods on weekdays during the morning periods (6:00 AM–11:00 AM). Taxi-enabled GPS tracking data obtained from Shenzhen city are used in the analysis. There are several findings in this study. Firstly, nearly half of the roads are significantly affected by the rainstorm. Secondly, the proportion of positive correlated roads is about 35 %, but there still are some roads with uncorrelated traffic speed variation rates (SVR) and rainfall intensities. Thirdly, the impact of the rainstorm on traffic speed is not homogeneous but with obvious spatial difference. This research provides useful information that can be used in traffic management on a city-wide scale under stormy weather.

scholarly journals Extracting Road Traffic Volume in the City before and during covid-19 through Video Remote Sensing

2021 ◽  
Vol 13 (12) ◽  
pp. 2329
Author(s):  
Elżbieta Macioszek ◽  
Agata Kurek
Keyword(s):  
Travel Behavior ◽  
Traffic Management ◽  
Road Traffic ◽  
Traffic Volume ◽  
The Road ◽  
Traffic Characteristics ◽  
Annual Average Daily Traffic ◽  
On The Road ◽  
The Impact ◽  
The City

Continuous, automatic measurements of road traffic volume allow the obtaining of information on daily, weekly or seasonal fluctuations in road traffic volume. They are the basis for calculating the annual average daily traffic volume, obtaining information about the relevant traffic volume, or calculating indicators for converting traffic volume from short-term measurements to average daily traffic volume. The covid-19 pandemic has contributed to extensive social and economic anomalies worldwide. In addition to the health consequences, the impact on travel behavior on the transport network was also sudden, extensive, and unpredictable. Changes in the transport behavior resulted in different values of traffic volume on the road and street network than before. The article presents road traffic volume analysis in the city before and during the restrictions related to covid-19. Selected traffic characteristics were compared for 2019 and 2020. This analysis made it possible to characterize the daily, weekly and annual variability of traffic volume in 2019 and 2020. Moreover, the article attempts to estimate daily traffic patterns at particular stages of the pandemic. These types of patterns were also constructed for the weeks in 2019 corresponding to these stages of the pandemic. Daily traffic volume distributions in 2020 were compared with the corresponding ones in 2019. The obtained results may be useful in terms of planning operational and strategic activities in the field of traffic management in the city and management in subsequent stages of a pandemic or subsequent pandemics.

scholarly journals Dynamic RFID Identification in Urban Traffic Management Systems

Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4225
Author(s):  
Bartosz Pawłowicz ◽  
Bartosz Trybus ◽  
Mateusz Salach ◽  
Piotr Jankowski-Mihułowicz
Keyword(s):  
Radio Frequency Identification ◽  
Traffic Management ◽  
Road Traffic ◽  
Object Identification ◽  
Urban Traffic ◽  
Mobile Object ◽  
Identification System ◽  
Dynamic Identification ◽  
Vehicle Identification ◽  
Simplified Algorithm

The paper covers the application of Radio Frequency IDentification (RFID) technology in road traffic management with regard to vehicle identification. Various infrastructure configurations for Automated Vehicle Identification (AVI) have been presented, including configurations that can be used in urban traffic as part of the Smart City concept. In order to describe the behavior of multiple identifications of moving vehicles, an operation model of the dynamic identification using RFID is described. While it extends the definition of the correct work zone, this paper introduces the concept of dividing the zone into sections corresponding to so-called inventory rounds. The system state is described using a set of matrices in which unread, read, and lost transponders are recorded in subsequent rounds and sections. A simplified algorithm of the dynamic object identification system was also proposed. The results of the simulations and lab experiments show that the efficiency of mobile object identification is conditioned by the parameters of the communication protocol, the speed of movement, and the number of objects.

Effectiveness of Predictive Weather-Related Active Transportation and Demand Management Strategies for Network Management

2017 ◽  
Vol 2667 (1) ◽  
pp. 71-87 ◽  
Author(s):  
Zihan Hong ◽  
Hani S. Mahmassani ◽  
Xiang Xu ◽  
Archak Mittal ◽  
Ying Chen ◽  
...  
Keyword(s):  
Traffic Management ◽  
Demand Management ◽  
Management Strategies ◽  
Weather Conditions ◽  
Active Transportation ◽  
Operational Conditions ◽  
Traffic Conditions ◽  
Adverse Weather ◽  
Traffic Performance ◽  
The Impact

This paper presents the development, implementation, and evaluation of predictive active transportation and demand management (ATDM) and weather-responsive traffic management (WRTM) strategies to support operations for weather-affected traffic conditions with traffic estimation and prediction system models. First, the problem is defined as a dynamic process of traffic system evolution under the impact of operational conditions and management strategies (interventions). A list of research questions to be addressed is provided. Second, a systematic framework for implementing and evaluating predictive weather-related ATDM strategies is illustrated. The framework consists of an offline model that simulates and evaluates the traffic operations and an online model that predicts traffic conditions and transits information to the offline model to generate or adjust traffic management strategies. Next, the detailed description and the logic design of ATDM and WRTM strategies to be evaluated are proposed. To determine effectiveness, the selection of strategy combination and sensitivity of operational features are assessed with a series of experiments implemented with a locally calibrated network in the Chicago, Illinois, area. The analysis results confirm the models’ ability to replicate observed traffic patterns and to evaluate the system performance across operational conditions. The results confirm the effectiveness of the predictive strategies tested in managing and improving traffic performance under adverse weather conditions. The results also verify that, with the appropriate operational settings and synergistic combination of strategies, weather-related ATDM strategies can generate maximal effectiveness to improve traffic performance.

Changes in surface level NO2 in the UK during the COVID-19 pandemic compared to predicted 2020 concentrations and the impact on O3.

2021 ◽  
Author(s):  
Rhianna Evans ◽  
James Lee ◽  
Will Drysdale
Keyword(s):  
Road Traffic ◽  
Chem Phys ◽  
Previous Method ◽  
International Travel ◽  
Urban Traffic ◽  
Urban Background ◽  
Random Forest Models ◽  
Primary Emissions ◽  
The Uk ◽  
The Impact

<p>Governments worldwide have used non pharmaceutical interventions known as lockdowns to contain the spread of the coronavirus pandemic, leading to a mass reduction in road traffic and international travel as working from home becomes the new normal. As a result, primary emissions of nitrogen oxides are expected to have largely decreased. A study of the UK’s first lockdown (Lee et al. 2020) used historical averages, taken between 2015 and 2019, as a baseline for comparison. This method is simplistic however does not fully account for the year to year meteorological variation. The UK’s first national lockdown was announced on 23<sup>rd</sup> March 2020 extending to 31<sup>st</sup> May 2020 and by mid-April traffic was reduced by 70% compared to normal according to the Department for Transport. We examined NO<sub>2</sub> and O<sub>3</sub>, measured by the UK’s Automatic Urban and Rural Network for the year 2020 consisting of 65 urban traffic and 61 urban background sites, for the lockdown period from 2000 to 2020. Between 2000 and 2019 NO<sub>2</sub> decreased by an average of 0.88 and 0.49 μg m<sup>-3</sup> per year at urban traffic and urban background sites respectively. In 2020, the lockdown caused a 20 μg m<sup>-3</sup> decrease in NO<sub>2</sub> at urban traffic sites, an equivalent of 26 years at the previous rate.</p><p>To improve on the previous method, we have constructed random forest models to simulate business as usual NO<sub>2</sub> and O<sub>3</sub> concentrations at AURN sites in 9 cities, allowing changes in meteorology to be fully accounted for. These simulations were then compared to lockdown measurements in 2020. We observed an average 55% decrease in NO<sub>2</sub> however O<sub>3</sub> concentrations were elevated with an average 29% increase. The total oxidant, O<sub>x</sub>, (sum of NO<sub>2</sub> and O<sub>3</sub>) experienced marginal change (< 1%) indicating the changes in NO<sub>2</sub> and O<sub>3</sub> were largely due to photochemical repartitioning. This has highlighted the importance of O<sub>3</sub> in urban locations in a future low NO<sub>x</sub> environment in the UK when electric vehicle fleets are adopted. </p><p> </p><p>Lee et al., Atmos. Chem. Phys., 2020, <strong>20</strong>, 15743 – 15759</p>

Study on Road Traffic Condition Identification Based on Floating Taxi

2011 ◽  
Vol 105-107 ◽  
pp. 2250-2254
Author(s):  
Xin Sheng Yao ◽  
Jian Hua Qu ◽  
Ji Lai Ying
Keyword(s):  
Traffic Management ◽  
Road Traffic ◽  
Sampling Interval ◽  
Urban Traffic ◽  
Traffic Information ◽  
Prototype System ◽  
Data Sampling ◽  
Traffic Condition ◽  
Wireless Communication Protocol ◽  
Information Update

This paper describes a prototype system based on floating taxi for traffic condition identification. The system consists of in-vehicle hardware units placed in floating taxi and backstage database that process all data send from the report units. The communication between the taxi and the database center is based on a very compact wireless communication protocol. The taxi sample size is decided by the variables: section traffic information update cycle, data sampling interval, section covering ratio. The test in a road section showed that the system is operational which could offer useful reference for urban traffic management and resident trips decision.

Improve urban traffic efficiency with prohibiting left-turn policy

2021 ◽  
Author(s):  
Meng-Qin Cheng ◽  
Lele Zhang ◽  
Xue-Dong Hu ◽  
Mao-Bin Hu
Keyword(s):  
Traffic Flow ◽  
Traffic Management ◽  
Critical Length ◽  
Urban Traffic ◽  
Flow Density ◽  
Route Guidance ◽  
Left Turn ◽  
Traffic Efficiency ◽  
Quickest Path ◽  
The Impact

Enhancing traffic flow plays an important role in the traffic management of urban arterial networks. The policy of prohibiting left-turn (PLT) at selected highly demanded intersections has been adopted as an attempt to increase the efficiency at these intersections. In this paper, we study the impact of PLT by mathematical analysis and simulations based on the cellular automaton model. Using the flow-density relation, three system performance indexes are examined: the average trip completion rate, the average traffic flow, and the average velocity of vehicles. Different route guidance strategies, including the shortest path and the quickest path, are investigated. We show that when left turn is prohibited, vehicles are distributed more homogeneously in the road network, and the system performs better and reaches a higher capacity. We also derive a critical length of link, above which the benefit of PLT will decrease.

scholarly journals THE EVALUATION OF REDUNDANCY FOR ROAD TRAFFIC NETWORKS

Transport ◽  
2016 ◽  
Vol 31 (4) ◽  
pp. 427-439 ◽  
Author(s):  
Rawia Ahmed El-Rashidy ◽  
Susan Grant-Muller
Keyword(s):  
Traffic Management ◽  
Road Traffic ◽  
Road Transport ◽  
Service Level ◽  
Transport Network ◽  
Dynamic Feature ◽  
Spare Capacity ◽  
Planning Stage ◽  
The Impact ◽  
Redundancy Index

This paper presents two redundancy indices for road traffic network junctions and also an aggregated network redundancy index. The proposed redundancy indices could be implemented to identify optimal design alternatives during the planning stage of the network junctions whereas the aggregated network redundancy index could assess the best control and management policies under disruptive events. Furthermore, effective measures of network redundancy are important to policy makers in understanding the current resilience and future planning to mitigate the impacts of greenhouse gases. The proposed junction indices cover the static aspect of redundancy, i.e. alternative paths, and the dynamic feature of redundancy reflected by the availability of spare capacity under different network loading and service level. The proposed redundancy indices are based on the entropy concept, due to its ability to measure the system configuration in addition to being able to model the inherent uncertainty in road transport network conditions. Various system parameters based on different combinations of link flow, relative link spare capacity and Relative Link Speed (RLS) were examined. However, the two redundancy indices developed from the combined RLS and relative link spare capacity showed strong correlation with junction delay and volume capacity ratio of a synthetic road transport network of Delft city. Furthermore, the developed redundancy indices responded well to demand variation under the same network conditions and supply variations. Another case study on Junction 3A in M42 motorway near Birmingham demonstrated that the developed redundancy index is able to reflect the impact of the Active Traffic Management (ATM) scheme introduced in 2006.

scholarly journals THE IMPACT OF ROAD GRADIENT AND TRUCK COMPOSITION ON THE TOLL ROAD TRAFFIC PERFORMANCE

2018 ◽  
Vol 16 (5) ◽  
Author(s):  
Nahry Yusuf ◽  
Dwi Setiyadi Sudrajat
Keyword(s):  
Road Traffic ◽  
City Centre ◽  
The Road ◽  
Toll Road ◽  
Traffic Performance ◽  
Traffic Stream ◽  
Traffic Speed ◽  
Road Gradient ◽  
Using Data ◽  
The Impact

Jakarta Outer Ring Road (JORR) is a toll road system that circles the outskirts of Jakarta, where the purpose of this road is to reduce congestion on the streets in Jakarta city centre. However, the high composition of trucks in JORR resulted in congestion of the road, which is hypothesized as attributed by the gradient of this road. This study aims to evaluate the impact of road gradient on truck and the overall traffic performance. Using data obtained from 24-hour traffic recording on selected JORR section, a VISSIM model was constructed to simulate traffic performance on some combinations of traffic and gradient conditions. In terms of macroscopic view point of traffic stream, the simulations showed that road gradient alone insignificantly affected truck speed, as well as the overall traffic speed. Instead, truck composition had more effect on the traffic speed rather than the gradient. In a particular composition of trucks different gradients did not significantly affect traffic speed differently. This implies that any policy to restrict truck access to toll road should depend mainly on the composition of truck itself, not the gradient of the road.

scholarly journals Research on the Intelligent Assignment Model of Urban Traffic Planning Based on Optimal Path Optimization Algorithm

2022 ◽  
Vol 2022 ◽  
pp. 1-7
Author(s):  
Yuan Lu ◽  
Shengyong Yao ◽  
Yifeng Yao
Keyword(s):  
Growth Rate ◽  
Optimization Algorithm ◽  
Traffic Congestion ◽  
Traffic Management ◽  
Road Traffic ◽  
Negative Impact ◽  
Optimal Path ◽  
Urban Traffic ◽  
Path Optimization ◽  
The Road

Congestion and complexity in the field of highway transportation have risen steadily in recent years, particularly because the growth rate of vehicles has far outpaced the growth rate of roads and other transportation facilities. To ensure smooth traffic, reduce traffic congestion, improve road safety, and reduce the negative impact of air pollution on the environment, an increasing number of traffic management departments are turning to new scientifically developed technology. The urban road traffic is simulated by nodes and sidelines in this study, which is combined with graph theory, and the information of real-time changes of road traffic is added to display and calculate the relevant data and parameters in the road. On this foundation, the dynamic path optimization algorithm model is discussed in the context of high informationization. Although the improved algorithm’s optimal path may not be the conventional shortest path, its actual travel time is the shortest, which is more in line with users’ actual travel needs to a large extent.

scholarly journals Speed-Density Model of Interrupted Traffic Flow Based on Coil Data

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Chen Yu ◽  
Jiajie Zhang ◽  
Dezhong Yao ◽  
Ruiguo Zhang ◽  
Hai Jin
Keyword(s):  
Traffic Flow ◽  
Traffic Management ◽  
Road Traffic ◽  
Flow Analysis ◽  
Density Model ◽  
Upper And Lower Bounds ◽  
Traffic Density ◽  
Density Relationship ◽  
Speed Fluctuation ◽  
The Impact

As a fundamental traffic diagram, the speed-density relationship can provide a solid foundation for traffic flow analysis and efficient traffic management. Because of the change in modern travel modes, the dramatic increase in the number of vehicles and traffic density, and the impact of traffic signals and other factors, vehicles change velocity frequently, which means that a speed-density model based on uninterrupted traffic flow is not suitable for interrupted traffic flow. Based on the coil data of urban roads in Wuhan, China, a new method which can accurately describe the speed-density relation of interrupted traffic flow is proposed for speed fluctuation characteristics. The model of upper and lower bounds of critical values obtained by fitting the data of the coils on urban roads can accurately and intuitively describe the state of urban road traffic, and the physical meaning of each parameter plays an important role in the prediction and analysis of such traffic.

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