Modeling Platoon Dispersal Pattern of Heterogeneous Road Traffic

2003 ◽  
Vol 1852 (1) ◽  
pp. 175-182 ◽  
Author(s):  
V. Thamizh Arasan ◽  
Shiraj Hussain Kashani

The quality of progression of a road traffic stream is one of the critical characteristics that must be quantified for operational analysis of traffic signals, particularly on urban roads. The parameter that has been found to best describe this characteristic of traffic streams is the arrival type. Though precise quantification of arrival type has been found to be difficult, the platoon ratio is a useful measure for this purpose. Thus, the quality of arrival of a traffic stream can be assessed by knowing the corresponding value of the platoon ratio. Study of arrival type over a wide range of traffic characteristics warrants theoretical modeling of traffic flow. In the study reported, an attempt was made to model heterogeneous traffic flow using an innovative technique. The developed model was used to study the arrival type of traffic streams, queue accumulation, and queue dissipation on approaches to traffic signals. The dispersal pattern of traffic platoons after vehicles pass a traffic signal was studied in detail. The effect of variation in traffic composition on traffic platoons was also analyzed.

Author(s):  
Lizhen Lin ◽  
Hongxia Ge ◽  
Rongjun Cheng

Under the Vehicle-to-Vehicle (V2V) environment, connected vehicles (CVs) can share the traveling information with each other to keep the traffic flow stable. However, the open network cooperation environment makes CVs vulnerable to cyberattacks, which leads to changes in driving behavior. The existing theories divide cyberattacks into three types: bogus information, replay/delay and collusion cyberattacks. In addition, the mixed flow consisting of truck and car is a common form of road traffic. In order to clarify the potential impact of cyberattacks on mixed traffic flow, this paper proposes an extended car-following model considering cyberattacks under CVs environment. Subsequently, the stability of the model is analyzed theoretically, and the stability condition of the model is obtained. The numerical simulation is carried out and the result shows that the cyberattacks lead to different degrees of traffic behavior hazards such as queue time extension, congestion and even rear end collision. Among them, cooperative attack is the most serious.


Author(s):  
Raunak Mishra ◽  
Pallav Kumar ◽  
Shriniwas S. Arkatkar ◽  
Ashoke Kumar Sarkar ◽  
Gaurang J. Joshi

This research was aimed at developing an area occupancy–based method for estimating passenger car unit (PCU) values for vehicle categories under heterogeneous traffic conditions on multilane urban roads for a wide range of traffic flow levels. First, PCU values of vehicle categories were determined according to the Transport and Road Research Laboratory definition and replaced the commonly considered measure of performance speed with area occupancy using simulation. The PCU values obtained were found to be significantly different for different volume-to-capacity ratios; this result shows that the PCU value is dynamic in nature. While the dynamic nature of PCU values is well appreciated, practitioners may prefer a single set of optimized PCU values (unique for each vehicle category). Hence, a new method with a matrix solution was proposed to estimate the optimized or unique set of PCU values with area occupancy as the performance measure. To check the credibility of the proposed method, the estimated PCU values were compared from existing guidelines regulated by the Indian Roads Congress (IRC) and values estimated with the widely accepted dynamic PCU concept of speed–area ratio. Results show that the PCU values suggested by IRC and the dynamic PCU concept using the speed–area ratio underestimate and overestimate the flows, respectively, at different traffic volumes. However, the values obtained with the area-occupancy concept were found to be consistent with the traffic flow in a cars-only traffic situation at different flow conditions. The derived set of optimized PCU values proposed can be useful for traffic engineers, researchers, and practitioners for capacity and level-of-service analysis under heterogeneous traffic conditions.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Akanksha Saxena ◽  
Nilanjan Chatterjee ◽  
Asha Rajvanshi ◽  
Bilal Habib

Abstract Roads impact wildlife in multiple ways, most conspicuous amongst which are animal-vehicle collisions (AVCs). Mitigation measures to reduce AVCs at the local scale are often centred on species-specific crossing zones and collision hotspots. However, at the road network scale, consideration of interactions among road, species and traffic characteristics influencing AVC occurrence is required to design effective mitigation strategies. We modelled traversability—the probability of an animal successfully crossing a road- across an Indian highway for six large mammal species under different scenarios of road and traffic characteristics. Among the study species, group-living and slow-moving animals had higher AVC probabilities that increased significantly with increasing traffic volume and proportions of heavy vehicles in the traffic flow. The risk of AVC was higher for species that were active near roadside habitat during peak traffic hours. Our approach could help identify roads that pose potential mortality risks to animals using empirical data on animal and traffic characteristics. Results suggest that regulating traffic volume and heterogeneity on existing road stretches could potentially reduce animal mortality and barrier effect. Mitigation on roads expected to carry heavy traffic loads passing through ecologically-sensitive areas should be prioritised to ensure traversability for animal communities.


2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Christian Schwartz ◽  
Tobias Hoßfeld ◽  
Frank Lehrieder ◽  
Phuoc Tran-Gia

The popularity of smartphones and mobile applications has experienced a considerable growth during the recent years, and this growth is expected to continue in the future. Since smartphones have only very limited energy resources, battery efficiency is one of the determining factors for a good user experience. Therefore, some smartphones tear down connectionsto the mobile network soon after a completed data transmission to reduce the power consumption of their transmission unit. However, frequent connection reestablishments caused by apps which send or receive small amounts of data often lead to a heavy signalling load within the mobile network. One of the major contributions of this paper is the investigation of the resulting tradeoff between energy consumption at the smartphone and the generated signalling traffic in the mobile network. We explain that this tradeoff can be controlled by the connection release timeout and study the impact of this parameter for a number of popular apps that cover a wide range of traffic characteristics in terms of bandwidth requirements and resulting signalling traffic. Finally, we study the impact of the timer settings on Quality of Experience (QoE) for web traffic. This is an important aspect since connection establishments not only lead to signalling traffic but also increase the load time of web pages.


2011 ◽  
Vol 97-98 ◽  
pp. 531-534
Author(s):  
Xin Qiu ◽  
An Xia Zheng ◽  
Ying Zhu ◽  
Bin Xu

Based on the survey of the traffic flow characteristics in the intersection, combined with the traffic flow basic principle and the existing research results at home and abroad, the road congestion condition is evaluated by determining the microcosmic evaluation index coefficient by VISSIM microcosmic simulation software. Then, the reasonable measures are put forward to improve urban road congestion condition. The analysis shows that the residents’ trip efficiency is improved and the quality of the urban road traffic condition is ameliorated.


10.29007/fzq3 ◽  
2018 ◽  
Author(s):  
Quazi Mishkatul Alam ◽  
Bejon Sarker ◽  
Biplob Biswas ◽  
Kazi Hasan Zubaer ◽  
Tarik Reza Toha ◽  
...  

Microscopic traffic simulators have become efficient tools to conduct different analytic studies on roads, vehicles, behavior of drivers, and critical intersections, which lead to- wards a well-planned traffic solution. Devising a realistic and sustainable traffic solution requires replication of the real traffic scenario in a simulator. For example, to simulate the traffic streams of developing and under developed countries, we need to simulate non-lane based heterogeneous traffic stream, i.e., motorized and non-motorized vehicles, road traffic behaviors such as irregular pedestrian, illegal parking, violation of laws pertaining lanes, etc. However, most of the existing traffic simulators are unable to mimic the unstructured road traffic streams of less developed countries with their diversified behaviors. Therefore, in this work, we propose a new microscopic traffic simulator to handle non-lane based heterogeneous traffic stream and on road traffic behaviors that generally occurred in the road networks of cities in less developed countries. Our simulator receives network topology, traffic routes, and traffic demand flow rates as input, visualizes the traffic flows, and provides traffic statistics. To evaluate sustainability of our proposed simulator in real-life scenarios, we calibrate the simulator using real traffic data. Our evaluation reveals 99% accuracy in terms of travel time.


Author(s):  
Jairo A. Gutiérrez ◽  
Wayne Ting

The objective of enabling the development of higher-level multimedia services with guaranteed quality of service (QoS) on networks has prompted developments that attempt to accommodate these new application requirements. Several architectures have been proposed, and a common basic functionality is emerging. Any new architecture that intends to satisfy the ever-growing need for bandwidth in the Internet while providing support for QoS guarantees needs to concern itself with the following aspects (Zhang, Deering, Estrin, Shenker, Zappala, 1993; Biswas, Lazar, Huard, Lim, Mahjoub, Pau, Suzuki, Torstensson, Wang and Weinstein, 1998): • Flow management: identifying the traffic characteristics of a flow so that the network can specify the QoS to be delivered to that flow • Compatibility with a wide range of routing protocols (Callon, Doolan, Feldman, Fredette, Swallow, Viswanathan, 1997) • Resource reservation • Admission control • Packet scheduling: including packet filtering and classification.


2018 ◽  
Vol 10 (0) ◽  
pp. 1-5
Author(s):  
Algimantas Danilevičius ◽  
Marijonas Bogdevičius

The traffic flows are influenced by various factors. In order to determine the characteristics of traffic flows in response to changing conditions, comprehensive research that is based on the best possible methods for simulating different street situations is necessary. The article determines the influence on transport flows due to changed conditions at the end of the simulated street. It presents the dynamic of the main parameters of the traffic flow (velocity, flow and density) depending on the time of changing traffic signals and the changed traffic flow density at the last simulated street point. The results are based on a discrete, mathematical model of traffic flows. The conditions determined by theoretical investigations determine the negative changes in the dynamics of traffic flows on a simulated street. Santrauka Transporto priemonių srautams turi įtakos įvairūs veiksniai. Norint nustatyti transporto srautų savybes priklausomai nuo pakitusių sąlygų reikalingi išsamūs tyrimai, grindžiami kuo tikslesniais metodais imituojant įvairių situacijų gatvėse modelius. Straipsnyje nustatoma įtaka transporto srautams dėl pakitusių sąlygų modeliuojamos gatvės pabaigoje. Pateikiama transporto srautų pagrindinių parametrų (greičio, eismo intensyvumo ir koncentracijos) dinamika priklausomai nuo šviesoforų signalų perjungimo laiko ir pakitusios transporto srauto koncentracijos paskutiniame modeliuojamos gatvės taške. Rezultatams gauti taikomas diskretinis transporto srautų matematinis modelis. Teoriniais tyrimais nustatytos sąlygos, lemiančios neigiamus pokyčius transporto srautų dinamikai modeliuojamame kelyje.


2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Zhijun Gao ◽  
Jiangfeng Wang ◽  
Xi Zhang ◽  
Jiakuan Dong ◽  
Lei Chen ◽  
...  

Traffic oscillations often occur in road traffic, they make traffic flow unstable, unsafe and inefficient. Emerging connected and autonomous vehicle (CAV) technologies are potential solutions to mitigating the traffic oscillations for the advantages that CAVs are controllable and cooperative. In order to study a control strategy and the effectiveness of CAVs in mitigating traffic oscillations and improving traffic flow and analyse the characteristics of homogeneous traffic flow made up of CAVs and heterogeneous traffic flow made up of CAVs and RVs when traffic oscillations appear in traffic flow. Firstly, the formation and propagation of traffic oscillations in a platoon of RVs are simulated and analysed. Then, a car-following control model is built to control the longitudinal motion of CAVs, and real-time information of preceding CAV is used in the model and this can make the motion of CAVs more cooperative. The model reflects an idea named “slow-in” and “fast-out,” and this idea is helpful to mitigate traffic oscillations. Then, numerical simulations of homogeneous traffic flow of a platoon of CAVs and simulations of heterogeneous traffic flow containing CAVs and RVs are conducted, and different penetration rates (0, 0.2, 0.4, 0.6, 0.8, and 1) of CAVs are considered in the simulations of heterogeneous traffic flow. The characteristics and evolution of traffic flow are analysed and some indexes reflecting traffic efficiency and stability are calculated and analysed. Simulation results show that there are smaller velocity fluctuation, less stopping time and shorter length of road occupied when vehicle platoon contains CAVs (penetration rates are from 0.2 to 1) compared to the platoon containing only RVs (without CAVs). As for the heterogeneous traffic flow containing CAVs and RVs, these three indexes decrease with the increase of penetration rates (from 0.2 to 1) of CAVs. These results indicate that CAVs with the car-following control model in vehicle platoon are beneficial for mitigating traffic oscillations and improving traffic flow.


2019 ◽  
Vol 298 ◽  
pp. 00084
Author(s):  
I. A. Teterina ◽  
E. V. Parsaev

To assess the quality of road traffic organization on environmental indicators, two methods of five regulations operating in the Russian Federation, which take into account the parameters of traffic flow, affecting the volume of emissions Pollutants. The parameter that affects the results of calculations in both methods is the average speed of movement. In real-world conditions on urban highways there are areas where the traffic flow is uneven (braking, acceleration, stopping), which entails an increase in the amount of pollutants from vehicles. At the same time, this uneven traffic is largely due to the existing the road design and traffic engineering on certain elements of the road network. This is the basis for the development of a methodology for calculating pollutant emissions to assess the quality of the traffic engineering, taking into account the uneven flow of traffic.


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