Influence Of Traffic Flow Research Articles

Coordinated operation of source–station–road–network system considering traffic flow uncertainty

Promoting large-scale transportation electrification and developing new solar energy harvesting and converting technologies are effective ways to achieve ’dual carbon goals’. In this paper, a new road energy harvesting technology, solar road (SR) power generation technology, is introduced. A SR power generation model considering the variation of solar radiation intensity, traffic flow and dynamic shadows of vehicles is constructed. Secondly, considering the uncertainty of traffic network (TN) caused by users’ stochastic routing behavior, a model of TN under stochastic user equilibrium (SUE) is constructed. Then the influence of traffic flow on the electric load of charging and battery swapping stations (CBSSs) is analyzed, and the local consumption strategy of SR is established. Meanwhile, information gap decision theory (IGDT) is introduced to reduce the impact of uncertainty on the system. Finally, the coupling system of IEEE-33 node of distribution network (DN) and Nguyen–Dupuis of TN is used to verify the effectiveness of the proposed model and optimal management method, which improves the utilization rate of solar energy, promotes carbon emission reduction, reduces the congestion degree of DN, and ensures the safe and stable operation of the system.

Coupled dispatching of regional integrated energy system under an electric-traffic environment considering user equilibrium theory

With large-scale electric vehicles (EVs) connected to the distribution network, the charging demand of EVs aggravates the peak-to-valley difference, which brings massive pressure to the power system. How to environmentally optimize the system considering the features of EVs’ charging demand has become a mainstream issue. To tackle this challenge, a low carbon economic dispatch model for the integrated energy system is proposed under an electric-traffic environment based on user equilibrium (UE) theory. This model considers carbon emission and multiple energy demand responses. First, to optimize the spatio-temporal distribution of the EV charging demand, a semi-dynamic traffic assignment (SDTA) model is constructed. This model considers vehicle travel, road congestion, and the influence of traffic flow in one interval to guide EVs to select an optimal route. Then, for reducing the carbon emission and promoting the reliability of the integrated energy system, a ladder carbon trading model and a demand response model for three different types of loads are proposed. Finally, a co-optimization system of traffic network, distribution network, and natural gas network is employed to illustrate the validity of the proposed model. The proposed model is demonstrated on the regional integrated energy system (RIES). The simulation results show that the peak-to-valley difference can be obviously relieved by introducing the SDTA model. In the meantime, via reasonable dispatching of the carbon trading, demand response, and Vehicle-to-grid (V2G) service, the multiple energy demands can be alleviated, ensuring the low carbon and economical operation of the RIES.

Evaluation and Optimization of Walkability of Children's School Travel Road for Accessibility and Safety Improvement.

(1) Background: In the context of a children friendly city, accessibility and safety are the basic needs of children’s pedestrian school travel. This study proposes a comprehensive evaluation method of pedestrian accessibility and safety for children’s school travel. (2) Methods: Firstly, the school travel network was constructed by simulating the path of children walking to school. Secondly, from the meso and micro dimensions, the impact factors of pedestrian accessibility and safety were combed out, and an evaluation index system was constructed. Finally, pedestrian accessibility and safety were evaluated based on the Space Syntax analysis and ArcGIS spatial analysis, and the results were superimposed and spatially differentiated. The new evaluation method was tested in the Jintang Road area in Hedong District, Tianjin, China. (3) Results: The pedestrian accessibility and safety of children’s school travel road in the study area needed to be improved. It was found that the main impact factors were the effective walking width, the spatial connectivity, the visual integration, the obstruction of pedestrian safety, the completeness of crossing facilities and the influence of traffic flow and put forward optimization strategies. After optimized simulation verification, the overall improvement was achieved. (4) Conclusion: The evaluation method is helpful to calculate the pedestrian accessibility and safety of children’s school travel, and help decision makers determine the design and management strategies of child-friendly streets.

Combined influence of traffic conditions, driving behavior, and type of road on fuel consumption. Real driving data from Madrid Area

The increasingly widespread use of vehicles has intensified fuel consumption and hence the emission of air pollutants, causing a negative environmental impact on both human health and climate change. It is well known that vehicle fuel consumption depends on several factors such as engine and vehicle technology, road characteristics, traffic conditions, and driver ability. Although the relationship between these variables has been subject of several researches, the combined influence of traffic flow with road type on vehicle fuel consumption has not yet been studied in depth. This paper aims to fill this gap by processing a large dataset of real-world driving data from an experiment carried out in Madrid, Spain; and to develop and validate a new approach using cluster analysis to define real traffic conditions. The results indicate that poor traffic conditions can significantly reduce vehicle’s energy efficiency and influence driving behavior, rather drastically depending on the road typology. While on high-capacity roads the speed covariance increases up to 73% in congestion, on low-capacity roads it increases by 31%, since road geometry also covers an important role; indeed, due to their complex and segmented geometry, local streets show 37% less vehicle’s energy efficiency compared with highways. The outcomes of this study suggest that energy efficiency depends on avoiding congestion on high-capacity roads, selecting green itineraries using the right road sections and having a more homogeneous driving behavior on low-capacity roads, through eco-driving whenever possible.

Split allocation model of intersection group oriented to network carrying capacity limit

In view of the network carrying capacity limit under over-saturated condition, a split allocation model of intersection group was developed, which takes total network delay, total output and total queue length as a comprehensive evaluation index. Based on the analysis of the influence of traffic flow turning, road section capacity, signal cycle length and split on traffic control, under the condition of network carrying capacity limit, the global optimization of intersection group splits was realized, taking the network traffic operation state as the basic judgment criterion and the corresponding constraint conditions were constructed. The numerical example analysis and simulation results show that the proposed model can ensure the traffic signal control effect under the premise of different demand states and control objectives, so that the effective prevention and quick dredging of traffic congestion can be realized under the condition of the network carrying capacity limit.

Mean-field theory for the Nagel-Schreckenberg model with overtaking strategy

Based on the Nagel-Schreckenberg (NS) model with periodic boundary conditions, a modified model considered overtaking strategy (NSOS) has been proposed [1, 2]. In this paper, we focus on the theoretical analysis of traffic flow for NSOS model by using mean-field method. In the special case of vmax = 1 where vehicles can not overtake preceding ones, the features of stationary state can be obtained exactly. However, in the case of vmax > 1 where overtaking happens, some approximative methods have to be took into account. The main results are that we find the reason why traffic flow is increased in the regime where densities exceed the maximum flow density, and the influence of traffic flow on the transition density is dominated by the braking probability p.

Концептуальный подход к построению базы данных информационной системы «Мониторинг концентрации выбросов загрязняющих веществ автомобильным транспортом»

The article discusses aspects of building a database of information system "Modeling of the influence of traffic flow on the emissions of polluting substances in atmospheric air of Voronezh". The database is realized with the help of technical means of dynamic information model of the territory, reflecting spatial and temporal structure, condition, and relationship between the individual elements of the simulated ecosystem. The presence of baseline information on the environmental parameters characterizing the components included in the atmospheric air, allows to provide ecologists with the results of processing of experimental data and give recommendations for elimination of emissions of polluting substances by motor automobile transport into atmosphere. The reporting database is a set of relational tables in MySQL database format, where each individual observation (measurement or setting of abundance of the pollutant in a particular sample of atmospheric air) is informationally associated with specification of location coordinates and characteristics of sampling sites (geographical aspect), as well as the date of expedition (time aspect). A generalized information model of the database consists of the following tables: information about the streets and districts of the city; the original data on the different types of transport and intensity of their movement in different parts of the city; output of pollutants: substance, mass, and concentration on certain streets and districts of the city; constant data about automotive pollutants (CH,SO,Pb, and others); other constant data, which are necessary for correct operation of the information system. The relevance of this topic is explained by increasing number of motor vehicles in the city of Voronezh and the solution to the problem of its impact on the quality of urban environment and public health.

Research on Abnormal Car-Following Behavior of Multi-Lane

Car-following is a radical traffic Car-following theory. Driving behavior and vehicles’ driving characteristic is very important in making intelligent traffic system. This paper investigates the headways of multi-lane, finds that there existed small headway in multi-lane highway in city Changchun, and its percentage can not be negligible, analyses several reasons of changing lanes in the car-following and the headway distributions with the abnormal behavior. Finally the theory small headway is generated by influence of traffic flow and the ratio of the left and right turning is concluded.

Epidemic immunization on scale-free networks with traffic flow

In this paper, considering the influence of network traffic flow on the spreading behaviors of epidemics and according to the mean-field theory, we investigate the epidemic immunization strategies in scale-free networks, and propose an improved acquaintance immunization mechanism. Theoretical analysis shows that considering the influence of traffic flow, the random immunization can hardly reduce the spreading velocity of epidemics if the density of vaccinated nodes is small. However, the targeted immunization can sharply depress the epidemic spreading even only a tiny fraction of nodes are vaccinated, and the effects of immunizing the most highly connected nodes and vaccinating the nodes with the largest betweenness are almost the same. We also find that if the network global information is unknown, compared with the classical acquaintance immunization strategy, the strategy proposed in this paper can be used to obtain good immune effect. Numerical simulations confirm the theoretical results.