scholarly journals Do Heavy Vehicles Always Have a Negative Effect on Traffic Flow?

2021 ◽  
Vol 11 (12) ◽  
pp. 5520
Author(s):  
Chang-Gyun Roh ◽  
Hyeonmyeong Jeon ◽  
Bongsoo Son

The purpose of this study is to analyze the effect of heavy vehicles on traffic flow on a two-lane highway. To achieve this goal, data was obtained from piezosensors on the Seoul–Chuncheon Expressway. Analysis of the data showed that, as everyone knows, the average speed of traffic flows decreases as the proportion of heavy vehicles increases. However, not only the speed decreased, but the speed deviation between vehicles decreased. In other words, it was found that within the traffic group that formed the same platoon, individual vehicles were forced to form similar speeds, resulting in a homogeneous rate. This means that heavy vehicles can be included in the traffic stream, reducing the chances of a vehicle-to-vehicle conflict. This kind of influence can be said to explain that heavy vehicles do not necessarily have a negative effect on traffic flow. In this way, we expect to be able to study ways to manage traffic flow by using the effects of low-speed vehicles.

2021 ◽  
Vol 40 (1) ◽  
pp. 1547-1566
Author(s):  
Shuang You ◽  
Yaping Zhou

The traffic flow prediction using cellular automata (CA) is a trendy research domain that identified the potential of CA in modelling the traffic flow. CA is a technique, which utilizes the basic units for describing the overall behaviour of complicated systems. The CA model poses a benefit for defining the characteristics of traffic flow. This paper proposes a modified CA model to reveal the prediction of traffic flows at the signalised intersection. Based on the CA model, the traffic density and the average speed are computed for studying the characteristics and spatial evolution of traffic flow in signalised intersection. Moreover, a CA model with a self-organizing traffic signal system is devised by proposing a new optimization model for controlling the traffic rules. The Sunflower Cat Optimization (SCO) algorithm is employed for efficiently predicting traffic. The SCO is designed by integrating the Sunflower optimization algorithm (SFO) and Cat swarm optimization (CSO) algorithm. Also, the fitness function is devised, which helps to guide the control rules evaluated by traffic simulation using the CA model. Thus, the cellular automaton is optimized using the SCO algorithm for predicting the traffic flows. The proposed Sunflower Cat Optimization-based cellular automata (SCO-CA) outperformed other methods with minimal travel time, distance, average traffic density, and maximal average speed.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Seolyoung Lee ◽  
Cheol Oh ◽  
Gunwoo Lee

Vehicle platooning service through wireless communication and automated driving technology has become a reality. Vehicle platooning means that several vehicles travel like a train on the road with a minimum safety distance, which leads to the enhancement of safety, mobility, and energy savings. This study proposed a framework for exploring traffic mobility and safety performance due to the market penetration rate (MPR) of truck platoons based on microscopic traffic simulations. A platoon formation algorithm was developed and run on the VISSIM platform to simulate automated truck maneuvering. As a result of the mobility analysis, it was found that the difference in network mobility performance was not significant up to MPR 80%. Regarding the mobility performance of the truck-designated lane, it was found that the average speed was lower than in other lanes. In the truck-designated lane of the on-ramp section, the average speed was identified to be approximately 33% lower. From the viewpoint of network safety, increasing the MPR of the truck platoon has a positive effect on longitudinal safety but has a negative effect on lateral safety. The safety analysis of the truck-designated lane indicated that the speed difference by lane of MPR 100% is 2.5 times higher than that of MPR 0%. This study is meaningful in that it explores traffic flow performance on mobility and safety in the process of platoon formation. The outcomes of this study are expected to be utilized as fundamentals to support the novel traffic operation strategy in platooning environments.


2015 ◽  
Vol 743 ◽  
pp. 526-532 ◽  
Author(s):  
C.M. Jiang ◽  
J.J. Lu ◽  
L.J. Lu

Based on the originally unprocessed data from the Official Platform of“110”Alarming Receiving Center (OP110ARC) of Shanghai Public Security Bureau (SPSB), 529 single-vehicle crashes reported during one year and a half which happened at the thirteen urban road tunnels going across the Huangpu River are used in this study. To investigate the factors affecting the crash influence severity levels, ordered probit regression is established. Several categories of factors are considered as explanatory variables in the models. The study finds that the entrance of the tunnels is the site where severe injury crashes trend to occur. Rainy and snowy days impose vehicles and motorists driving via the tunnel sections in danger. Tunnels with a low speed limit (40 km/h in this study) may be not as safe as we thought before. Two-wheel vehicles without sufficient physical protection for its drivers and heavy vehicles also show a negative effect on the operation safety of single-vehicle at these studied tunnels. Alcohol involved drivers are more likely to suffer from a severe crashes and gets badly hurt.


Electronics ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1221
Author(s):  
Anum Mushtaq ◽  
Irfan ul Haq ◽  
Wajih un Nabi ◽  
Asifullah Khan ◽  
Omair Shafiq

Connected Autonomous Vehicles (AVs) promise innovative solutions for traffic flow management, especially for congestion mitigation. Vehicle-to-Vehicle (V2V) communication depends on wireless technology where vehicles can communicate with each other about obstacles and make cooperative strategies to avoid these obstacles. Vehicle-to-Infrastructure (V2I) also helps vehicles to make use of infrastructural components to navigate through different paths. This paper proposes an approach based on swarm intelligence for the formation and evolution of platoons to maintain traffic flow during congestion and collision avoidance practices using V2V and V2I communications. In this paper, we present a two level approach to improve traffic flow of AVs. At the first level, we reduce the congestion by forming platoons and study how platooning helps vehicles deal with congestion or obstacles in uncertain situations. We performed experiments based on different challenging scenarios during the platoon’s formation and evolution. At the second level, we incorporate a collision avoidance mechanism using V2V and V2I infrastructures. We used SUMO, Omnet++ with veins for simulations. The results show significant improvement in performance in maintaining traffic flow.


Author(s):  
Xiaolong Xu ◽  
Zijie Fang ◽  
Lianyong Qi ◽  
Xuyun Zhang ◽  
Qiang He ◽  
...  

The Internet of Vehicles (IoV) connects vehicles, roadside units (RSUs) and other intelligent objects, enabling data sharing among them, thereby improving the efficiency of urban traffic and safety. Currently, collections of multimedia content, generated by multimedia surveillance equipment, vehicles, and so on, are transmitted to edge servers for implementation, because edge computing is a formidable paradigm for accommodating multimedia services with low-latency resource provisioning. However, the uneven or discrete distribution of the traffic flow covered by edge servers negatively affects the service performance (e.g., overload and underload) of edge servers in multimedia IoV systems. Therefore, how to accurately schedule and dynamically reserve proper numbers of resources for multimedia services in edge servers is still challenging. To address this challenge, a traffic flow prediction driven resource reservation method, called TripRes, is developed in this article. Specifically, the city map is divided into different regions, and the edge servers in a region are treated as a “big edge server” to simplify the complex distribution of edge servers. Then, future traffic flows are predicted using the deep spatiotemporal residual network (ST-ResNet), and future traffic flows are used to estimate the amount of multimedia services each region needs to offload to the edge servers. With the number of services to be offloaded in each region, their offloading destinations are determined through latency-sensitive transmission path selection. Finally, the performance of TripRes is evaluated using real-world big data with over 100M multimedia surveillance records from RSUs in Nanjing China.


Author(s):  
Jianzhong Chen ◽  
Yang Zhou ◽  
Jing Li ◽  
Huan Liang ◽  
Zekai Lv ◽  
...  

In this paper, an improved multianticipative cooperative adaptive cruise control (CACC) model is proposed based on fully utilizing multivehicle information obtained by vehicle-to-vehicle communication. More flexible, effective and practical spacing strategy is embedded into the model. We design a new lane-changing rule for CACC vehicles on the freeway. The rule considers that CACC vehicles are more inclined to form a platoon for coordinated control. Furthermore, we investigate the effect of CACC vehicles on two-lane traffic flow. The results demonstrate that introducing CACC vehicles into mixed traffic and forming CACC platoon to cooperative control can improve traffic efficiency and enhance road capacity to a certain extent.


Author(s):  
Regina Gražulevičienė ◽  
Inga Bendokienė

The aim of the study was to assess the influence of truck traffic on acoustic pollution in two Kaunas districts crossed by highways‐ Eiguliai and Šilainiai. Composition of traffic flow and noise measurements were conducted near the main streets and national highways that cross the districts. GIS and statistical software SPSS 12.01 were used for the data analysis. The study results showed that mean noise level near the main streets was 70 dB(A) in the daytime,‐ 68.6 dB(A) in the evening and at night it was 61.1 dB(A) in Eiguliai, and in Šilainiai it was 67 dB(A), 65 dB(A) and 58 dB(A), correspondingly. On the highways, crossing the districts, heavy vehicles compose about 3 times higher part of total traffic flow during the day and about 2 times in the evening compared to other main streets. The noise level depended on the traffic flow and correlation coefficient fluctuated from 0.77 to 0.85. The modelling of traffic flow showed, that the increase of trucks proportion by 2 percent would increase the traffic noise by 1.1 dB(A) in the streets with traffic flow of 300 veh./hour or more, and by 1.8 dB(A) with traffic flow of 200 veh./hour or less. Our findings suggest that the influence of heavy vehicles on acoustic pollution is higher in the districts with lower traffic flow. Santrauka Tyrimo tikslas – nustatyti krovininio autotransporto įtaką akustinei taršai Kauno mikrorajonuose, kuriuos kerta respublikinės reikšmės magistralės – Islandijos plentas ir vakarinis lankstas. Aplinkos triukšmo lygis ir transporto srautų intensyvumas Eigulių ir Šilainių seniūnijoje buvo matuotas 34 taškuose – dieną, vakare ir naktį. Duomenims apdoroti taikyta geografinių informacinių (GIS) sistemų technologijos, SPSS 12.0.1 ir Statistica 15 statistinės analizės paketai. Tyrimų rezultatai: vidutinis ekvivalentinis triukšmo lygis Eigulių seniūnijoje dieną prie pagrindinių gatvių siekė 70 dBA, vakare – 68,6 dBA, o naktį – 61,1 dBA ir iš esmės nesiskyrė nuo Šilainių seniūnijos, atitinkamai 67 dBA, 65 dBA ir 58 dBA. Magistraliniuose keliuose, kertančiuose Eigulių ir Šilainių seniūnijas, vidutinis transporto srautų intensyvumas dieną ir vakare buvo 5 kartus, naktį 6 kartus didesnis nei vidutinis srautų intensyvumas pagrindinėse gatvėse tuo pačiu metu, o krovininio autotransporto dalis dieną 3 kartus, o vakare 2 kartus viršijo vidutinius pagrindinių gatvių srautus. Nustatyta sąsaja tarp transporto srautų intensyvumo ir triukšmo lygio: Eigulių seniūnijos dienos koreliacijos koeficientas buvo 0,85, vakaro ir nakties – 0,83, o Šilainių seniūnijos – atitinkamai 0,78, 0,77 ir 0,80. Transporto srautų sudėties modeliavimo duomenimis, padidėjus krovininio transporto proporcijai 2 %, gatvėse, kuriose transporto srautas didesnis nei 300 aut./val., triukšmo lygis padidėtų 1,1 dBA, o kur transporto srautas mažesnis nei 200 aut./val., triukšmo lygis padidėtų 1,8 dBA (koreliacijos koeficientas – 0,63). Krovininio transporto įtaka akustinei taršai didesnė mikrorajonuose, kuriuose transporto srautai nedideli. Резюме Целью данной работы было изучить влияние грузового автотранспорта на акустическое загрязнение в микрорайонах города Каунаса, которые пересекают трассы государственного значения. Это шоссе Исландиос и объезд Вакаринис. Состав транспортного потока определялся и уровень шума измерялся около главных улиц микрорайонов. Результаты исследования показали, что средний уровень шума днем был 70 dBA, вечером – 68,6 dBA, ночью – 61,1 dBA. На трассах государственного значения, пересекающих микрорайоны, по сравнению с другими улицами потоки грузовых автомобилей были в 3 раза больше днем и 2 раза больше вечером. Установлена зaвисимость между величиной транспортного потока и шума (r = 0,77–0,85). Моделирование состава транспортного потока показало, что при увеличении на улицах грузового транспорта на 2% с 300 авт./час и больше шум увеличивается на 1,1 dBA, а при количестве грузового транспорта, составляющем 200 авт./час и меньше, шум возрастает на 1,8 dBA. Влияние грузового автотранспорта на акустическое загрязнение больше в микрорайонах с небольшим транспортным потоком.


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