scholarly journals The Impact of Automated Vehicles on Traffic Flow and Road Capacity on Urban Road Networks

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Ji Eun Park ◽  
Wanhee Byun ◽  
Youngchan Kim ◽  
Hyeonjun Ahn ◽  
Doh Kyoum Shin

Automated vehicles (AVs) are believed to have great potential to improve the traffic capacity and efficiency of the current transport systems. Despite positive findings of the impact of AVs on traffic flow and potential road capacity increase for highways, few studies have been performed regarding the impact of AVs on urban roads. Moreover, studies considering traffic volume increase with a mixture of AVs and human-driven vehicles (HDVs) have rarely been conducted. Therefore, this study investigated the impact of gradual increments of AV penetration and traffic volume on urban roads. The study adopted a microsimulation approach using VISSIM with a Wiedmann 74 model for car-following behavior. Parameters for AVs were set at the SAE level 4 of automation. A real road network was chosen for the simulation having 13 intersections in a total distance of 4.5 km. The road network had various numbers of lanes from a single lane to five lanes in one direction. The network consists of a main arterial road and a parallel road serving nearby commercial and residential blocks. In total, 36 scenarios were investigated by a combination of AV penetrations and an increase in traffic volumes. The study found that, as AV penetration increased, traffic flow also improved, with a reduction of the average delay time of up to 31%. Also, as expected, links with three or four lanes had a more significant impact on the delay. In terms of road capacity increase, when the penetration of AVs was saturated at 100%, the road network could accommodate 40% more traffic.

2019 ◽  
Vol 17 ◽  
Author(s):  
Zakiah Ponrahono ◽  
Noorain Mohd Isa ◽  
Ahmad Zaharin Aris ◽  
Rosta Harun

The inbound and outbound traffic flow characteristic of a campus is an important physical component of overall university setting. The traffic circulation generated may create indirect effects on the environment such as, disturbance to lecturetime when traffic congestion occurs during peak-hours, loss of natural environment and greenery, degradation of the visual environment by improper or illegal parking, air pollution from motorized vehicles either moving or in idle mode due to traffic congestion, noise pollution, energy consumption, land use arrangement and health effects on the community of Universiti Putra Malaysia (UPM) Serdang. A traffic volume and Level of Service (LOS) study is required to facilitate better accessibility and improves the road capacity within the campus area. The purpose of this paper is to highlight the traffic volume and Level of Service of the main access the UPM Serdang campus. A traffic survey was conducted over three (3) weekdays during an active semester to understand the traffic flow pattern. The findings on traffic flow during peak hours are highlighted. The conclusions of on-campus traffic flow patterns are also drawn.


2019 ◽  
Vol 2019 (9) ◽  
pp. 29-38
Author(s):  
Nina Kozaczka ◽  
Stanisław Gaca

The article evaluates the impact of autonomous vehicles on road infrastructure de- sign, road traffic conditions and safety based on a review of existing literature. Levels of driv- ing automation and equipment of self-driving vehicles were presented. Attention was drawn to the benefits of developing communication systems between vehicle and the environment. The possible negative impact of autonomous vehicles on mixed traffic capacity was noted. The potential needs to adapt the road infrastructure to the traffic flow of automated vehicles were also presented. Separation of the lane, dedicated to self-driving vehicles, with a high share of these vehicles was presented as an element that improves the flow of traffic and safe- ty. Keywords: Autonomous vehicles; Road infrastructure; Self-driving cars


2021 ◽  
Author(s):  
Sandra Mihalinac ◽  
Maja Ahac ◽  
Saša Ahac ◽  
Miroslav Šimun

It is a well-known fact that the data on road traffic flow characteristics is essential for sustainable road network management. First road traffic volume counts date back to the 1950s when short-term periodic road traffic counts were carried out in cities worldwide. Manual traffic counting is one of the oldest and most technologically simple methods to obtain data on road traffic volume and its composition. Today, because of the ever-growing road transport demand, it has become clear that the development of Intelligent Transport Systems (ITS) is vital to increase safety and tackle increasing emission and congestion problems. The introduction of ITS highly depends on the quality and quantity of traffic data. Under the growing requirement of long-term traffic flow information, various traffic data collection methods have evolved. They allow systematic recording of the traffic flow volume and composition but also vehicle speed, total gross weight, number of axles, axle load and travel destination. This data, which is collected continuously over longer periods, enables a detailed analysis of traffic flows, and represents the basis for decision making in planning, designing, construction and maintenance of road infrastructure. This paper gives an overview of traditional and emerging traffic data collection methods - both fixed and mobile - and the analysis of the current road traffic data collection methods used on the Croatian road network, in terms of their potential and limitations.


2021 ◽  
Author(s):  
Dražen Cvitanić ◽  
Biljana Maljković

Elements of the city road network that determine its capacity are signalized intersections. Their capacity depends of many factors: traffic volume and distribution, traffic flow structure, signal timing, and number of bicyclists and pedestrians. However, the starting parameter for calculation of intersection capacity is saturation headway. This research explores the influence of weather conditions and purpose of trip on saturation headway. Saturation headways were determined on few intersections in the morning peak hour of working and weekend day, in good and bad weather conditions. The impact of different trip purposes and different weather conditions on intersection capacity is analysed, as well as the influence of using mean and median values of saturation headway when calculating the intersection capacity.


2018 ◽  
Vol 181 ◽  
pp. 06001
Author(s):  
Noor Mahmudah ◽  
Rizkie Akbar ◽  
Muchlisin

Due to imbalance of road capacity and traffic volume, so traffic congestion will be occurred either along the road and intersection. Demak Ijo intersection is one of signalized junction located in the western part of Yogyakarta with high traffic volume so traffic congestion is frequently occurred. The aim of this study is to analyze the performance of existing traffic condition and then estimate the congestion cost at signalized intersection by modeling (simulation) using Vissim 9. The analysis results show that existing traffic condition is in very bad condition (level F), average delay of 80 seconds, average queue length of 48.73 meters with congestion cost is about Rp. 2,830,336 per hour.


2021 ◽  
Vol 1202 (1) ◽  
pp. 012034
Author(s):  
Valentina Amare ◽  
Juris Smirnovs

Abstract The highest number of road accidents occurs at junctions. One of the aims of traffic organisation is to improve traffic safety in these areas. Based on a variety of indices – road capacity, points of conflict, number, and severity of road traffic accidents – different alternatives for junctions are evaluated. However, the road network has many junctions and roads serve to travel from point "A" to point "B" at a given time. Therefore, one of the most important tasks when addressing the issue of road safety is to find a rational way of improving the safety without losing the importance of the road. The aim of this paper is to analyse the impact of different junctions on the road network and basing on actual data develop a method for the evaluation of different types of junctions with respect to road class.


2019 ◽  
Vol 17 (10) ◽  
Author(s):  
Zakiah Ponrahono ◽  
Noorain Mohd Isa ◽  
Ahmad Zaharin Aris ◽  
Rosta Harun

The inbound and outbound traffic flow characteristic of a campus is an important physical component of overall university setting. The traffic circulation generated may create indirect effects on the environment such as, disturbance to lecturetime when traffic congestion occurs during peak-hours, loss of natural environment and greenery, degradation of the visual environment by improper or illegal parking, air pollution from motorized vehicles either moving or in idle mode due to traffic congestion, noise pollution, energy consumption, land use arrangement and health effects on the community of Universiti Putra Malaysia (UPM) Serdang. A traffic volume and Level of Service (LOS) study is required to facilitate better accessibility and improves the road capacity within the campus area. The purpose of this paper is to highlight the traffic volume and Level of Service of the main access the UPM Serdang campus. A traffic survey was conducted over three (3) weekdays during an active semester to understand the traffic flow pattern. The findings on traffic flow during peak hours are highlighted. The conclusions of on-campus traffic flow patterns are also drawn.


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.


2017 ◽  
Vol 2017 ◽  
pp. 1-8
Author(s):  
Zhenjun Zhu ◽  
Yang Lu ◽  
Jun Zeng ◽  
Hongsheng Chen

In order to reduce the impact of highway traffic accidents on surrounding road networks, accident influence area should be determined reasonably. According to the relationship between vehicle bypass decision-making index and threshold under accident condition, the vehicles’ route choice behavior at upstream of the accident spot can be divided into two types: bypass and nonbypass. Under nonbypass condition, the method of using traffic wave theory was put forward to determine the upstream influence area. Under bypass condition, the total number of bypass vehicles is determined based on bypass decision-making index being greater than bypass threshold. Assignment algorithms based on routes were proposed. Using improved Logit model to get the selection probability and the traffic flow of each route, then traffic flow of surrounding links could be obtained. At last, the road network influenced by the accident could be determined by comparing with the level of service of each link under normal condition. The paper takes Beijing-Kunming highway as an example, and the results show that the road network formed by the influenced links was highway traffic accident influence area. Comparing with the actual survey results, correctness of the calculation method is verified. Therefore, the analytical method based on bypass decision-making is applicable to determining highway accident influence area.


2021 ◽  
Vol 2021 (24) ◽  
pp. 159-168
Author(s):  
Anatolii Palchyk ◽  

Introduction. The analysis of road capacity is carried out. Problem statement. One of the reasons for the appointment of the road reconstruction or part of it is the deterioration of traffic safety, resulting in an increase in the number of victims and material losses during traffic accidents. Road capacity is an important indicator during highway reconstruction. The analysis of the road section capacity makes it possible to assess the work of the road during its entire life cycle from the moment of its commissioning to the moment of reconstruction. Existing methods for determining the practical traffic lane capacity, the maximum traffic volume on the highway section give ambiguous results that need to be improved. Purpose. The purpose of the work is to study the average speed, which is one of the factors that determine the maximum traffic volume on the road. Materials and methods. Analysis of the results of experimental studies of average speeds of free movement of different type of vehicles on roads of different categories. Results. The general form of equations of dependence of average traffic speed on radii of horizontal curves and speed on a longitudinal slope is established; the impact of road conditions on the traffic speed according to the study of graphs of average speeds before and after the improvement of traffic conditions on road sections was analyzed. Conclusions. Based on the assessment of traffic conditions with the provision of maximum traffic volume on road sections between intersections and junctions, which determine the traffic volume between them, it is possible to address the need for partial or complete reconstruction of the highway. Keywords: road capacity, traffic volume, highway, intersection, junctions, traffic speed, highway reconstruction.


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