Simulation of vehicle traffic flow on the block with the impact of buses' stopping

Author(s):  
Zheng Sun
Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4299
Author(s):  
Miroslaw Smieszek ◽  
Vasyl Mateichyk ◽  
Magdalena Dobrzanska ◽  
Pawel Dobrzanski ◽  
Ganna Weigang

The development of the COVID-19 pandemic and the related lockdown had a major impact on vehicle traffic in cities. Based on available data from the selected city of Rzeszow, Poland, it was decided to assess changes in vehicle traffic and the impact of these changes on roadside environmental pollution. As part of the research, data from the first half of 2020 regarding vehicle traffic on selected streets of the city and on the city’s inlet routes were analyzed. For the selected road sections, changes in hourly traffic volume in 2020, compared with 2019, were also determined. With data on traffic volume, an attempt was made to estimate the impact of changes in traffic volume on air pollution in the city. Research on air pollution from motor vehicles was focused on a selected section of a city road that was equipped with an automatic air pollution measurement station located very close to the road. Additionally, at the road intersection and in the vicinity of the measuring station, a sensor was installed in the roadway to count passing vehicles. A preliminary analysis of air pollution data revealed that factors such as wind speed and direction and outside temperature had a large impact on measurement results. To eliminate the influence of these factors and to obtain data concerning only contamination originating from motor vehicles traveling along the road, an appropriate mathematical model of the traffic flow–roadside environment system was built. This model was designed to determine the air pollution in the vicinity of the road generated by traffic flow. The constructed model was verified, and the conditions for its use were determined in order to study the impact of traffic and roadside environment on the level of air pollution from harmful exhaust substances. It was shown that at certain times of the day, especially at low temperatures, other sources of harmful emissions related to home heating play a major role in air pollution in the city.


2021 ◽  
Vol 3 (8) ◽  
Author(s):  
Ting Liu ◽  
Gabriel Lodewijks

Abstract Abstract On the basis of the influence of dry season on ship traffic flow, the gathering and dissipating process of ship traffic flow was researched with Greenshields linear flow—density relationship model, the intrinsic relationship between the ship traffic congestion state and traffic wave in the unclosed restricted channel segment was emphatically explored when the ship traffic flow in a tributary channel inflows, and the influence law of multiple traffic waves on the ship traffic flow characteristics in unclosed restricted segment is revealed. On this basis, the expressions of traffic wave speed and direction, dissipation time of queued ships and the number of ships affected were provided, and combined with Monte Carlo method, the ship traffic flow simulation model in the restricted channel segment was built. The simulation results show that in closed restricted channel segment the dissipation time of ships queued is mainly related to the ship traffic flow rate of segments A and C, and the total number of ships affected to the ship traffic flow rate of segment A. And in unclosed restricted channel segment, the dissipation time and the total number of ships affected are also determined by the meeting time of the traffic waves in addition to the ship traffic flow rate of segments. The research results can provide the theoretical support for further studying the ship traffic flow in unclosed restricted channel segment with multiple tributaries Article Highlights The inflow of tributaries' ship traffic flows has an obvious impact on the traffic conditions in the unenclosed restricted channel segment. The interaction and influence between multiple ship traffic waves and the mechanism of generating new traffic waves are explained. The expression of both dissipation time of queued ships and the total number of ships affected in the closed and unclosed restricted channel segment are given.


2014 ◽  
Vol 915-916 ◽  
pp. 459-463
Author(s):  
He Quan Zhang

In order to deal with the impact on traffic flow of the rule, we compare the influence factors of traffic flow (passing, etc.) into viscous resistance of fluid mechanics, and establish a traffic model based on fluid mechanics. First, in heavy and light traffic, we respectively use this model to simulate the actual segment of the road and find that when the traffic is heavy, the rule hinder the further increase in traffic. For this reason, we make further improvements to the model to obtain a fluid traffic model based on no passing and find that the improved model makes traffic flow increase significantly. Then, the improved model is applied to the light traffic, we find there are no significant changes in traffic flow .In this regard we propose a new rule: when the traffic is light, passing is allowed, but when the traffic is heavy, passing is not allowed.


2018 ◽  
Vol 2018 ◽  
pp. 1-5
Author(s):  
Tao Wang ◽  
Jing Zhang ◽  
Guangyao Li ◽  
Keyu Xu ◽  
Shubin Li

In the traditional optimal velocity model, safe distance is usually a constant, which, however, is not representative of actual traffic conditions. This paper attempts to study the impact of dynamic safety distance on vehicular stream through a car-following model. Firstly, a new car-following model is proposed, in which the traditional safety distance is replaced by a dynamic term. Then, the phase diagram in the headway, speed, and sensitivity spaces is given to illustrate the impact of a variable safe distance on traffic flow. Finally, numerical methods are conducted to examine the performance of the proposed model with regard to two aspects: compared with the optimal velocity model, the new model can suppress traffic congestion effectively and, for different safety distances, the dynamic safety distance can improve the stability of vehicular stream. Simulation results suggest that the new model is able to enhance traffic flow stability.


2021 ◽  
Vol 9 (11) ◽  
pp. 1283
Author(s):  
Mate Baric ◽  
Robert Mohovic ◽  
Djani Mohovic ◽  
Vinko Pavic

The latest container vessel grounding in the Suez Canal, which occurred on 23 March 2021 (the Ever Given), raised many questions regarding the safety of navigation. The sudden concern about safety is due to fears that traffic flow through the Suez Canal could be blocked for longer periods of time. Besides external forces imposed by wind, in this case bank effect had a significant influence on the ship’s grounding. Bank effect occurs due to restricted water flow caused by narrow waterways. Many fairway design standards consider sloped banks such as those of the Suez Canal as unsubstantial in bank-effect forces. This paper analyses the impact of sloped banks on container ship trajectory and proposes minimal distances that may decrease bank-effect forces in order to reduce the risk of vessel grounding and increase the safety of navigation. However, this type of accident has happened before and may occur again due to a small sailing distance from the bank in cases where vessel speed is increased.


2018 ◽  
Vol 4 (2) ◽  
pp. 18
Author(s):  
Muhammad Reza Nugraha ◽  
Dwi Prasetyanto ◽  
Andrean Maulana

ABSTRAKPelican crossing merupakan jenis penyeberangan yang dioperasikan oleh penyeberang jalan yang bertujuan memberikan keselamatan kepada penyeberang. Tujuan dari penelitian ini adalah menentukan jenis penyeberangan dan mencari pemodelan tundaan dan panjang antrian akibat pelican crossing di jalan Asia Afrika Bandung. Data penelitian ini adalah frekuensi penyeberangan, jumlah penyeberang, jumlah kendaraan terhenti, arus lalu lintas, tundaan dan panjang antrian kendaraan. Analisis penentuan jenis penyeberangan menggunakan perhitungan PV2  dan analisis pemodelan tundaan dan panjang antrian menggunakan regresi linier berganda. Dari perhitungan PV2 didapatkan hasil PV2=2,49*109 yang berarti termasuk kepada jenis penyeberangan pelikan dengan lapak tunggu. Model yang mewakili hubungan antara panjang antrian (Y) dengan jumlah kendaraan terhenti (X1) dan frekuensi penyeberangan (X2) adalah Y=2,201 + 3,203X1 + 3,510X2. Model yang mewakili hubungan antara tundaan  (Y) dengan variabel bebas yang sama adalah Y=0,709 + 2,656X1 + 7,645. Panjang antrian maksimum sebesar 78,072 meter dan tundaan maksimum sebesar 89,826 detik.Kata kunci: pelican crossing, panjang antrian, tundaanABSTRACTPelican crossing is a type of pedestrian cross which is operated by pedestrian with purpose is to give safety for the crosser. The aim of this study are to determine the type of crossing and find the model of delay and queue length because of pelican crossing at Asia Afrika Street Bandung. The data of this study are crossing frequency, amount of crossers, amount of stopped vehicle, traffic flow, delay and queue length vehicle. Analysis for the type of the crossing obtained by calculation of and analysis of model delay and queue length are use multiple regression. The result from the calculation of PV2  is PV2=2,49*109 which is the type of the crossing is pelican with protector. The represent model of relation between the queue length (Y) with amount of stopped vehicle  and crossing frequency (X2) is  Y=2,201 + 3,203X1 + 3,510X2.The represent model of relation between delay (Y) with same dependent variable is Y=0,709 + 2,656X1 + 7,645. The maximum queue length is 78,072 meters and the delay maximum is 89,826 seconds.Keyword: pelican crossing, the queue length, delay


Author(s):  
Parthkumar Patel ◽  
H.R. Varia

Safe, convenient and timely transportation of goods and passengers is necessary for development of nation. After independence road traffic is increased manifold in India. Modal share of freight transport is shifted from Railway to roadways in India. Road infrastructures continuously increased from past few decades but there is still need for new roads to be build and more than three forth of the roads having mixed traffic plying on it. The impact of freight vehicles on highway traffic is enormous as they are moving with slow speeds. Nature of traffic flow is dependent on various traffic parameters such as speed, density, volume and travel time etc. As per ideal situation these traffic parameters should remain intact, but it is greatly affected by presence of heavy vehicle in mixed traffic due to Svehicles plying on two lane roads. Heavy vehicles affect the traffic flow because of their length and size and acceleration/deceleration characteristics.  This study is aimed to analyse the impact of heavy vehicles on traffic parameters.


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