scholarly journals Research of time headways at roundabout approaches

2021 ◽  
Vol 67 (3) ◽  
pp. 23-28
Author(s):  
Dunja Radović ◽  
Vuk Bogdanović
Keyword(s):  
Traffic Flow ◽  
Flow Characteristics ◽  
Driver Behaviour ◽  
The Road ◽  
Traffic Conditions ◽  
Flow Parameters ◽  
Standard Procedures ◽  
Capacity Calculation ◽  
The Impact

It is known that traffic flow characteristics have significant influence at the capacity of all functional segments of the road and street network. One of the most important traffic flow parameters which affect the capacity of roundabouts is follow-up headway at minor approaches of roundabouts. This traffic flow parameter, like the most others, depends on driver behaviour, i.e. local traffic conditions. This paper presents the research results related to follow-up headway at three roundabouts obtained by the photographic method. This data collection method is chosen because its application completely eliminates the impact of research at behaviour of traffic participants. After the research, a representative sample is formed and its processing and analysis led to conclusions about the value of follow-up headway at roundabouts which can be applied in standard procedures for capacity calculation at roundabouts in midsize cities of our region.

scholarly journals The impact of the average traffic flow speed on occurrence risk of road crash

2019 ◽  
Vol 65 (2) ◽  
pp. 29-36
Author(s):  
Dalibor Pešić ◽  
Boris Antić ◽  
Emir Smailovic ◽  
Bojana Todosijević
Keyword(s):  
Traffic Flow ◽  
Flow Characteristics ◽  
Flow Speed ◽  
Flow Density ◽  
Average Speed ◽  
Flow Parameters ◽  
Flow Speeds ◽  
Road Crash ◽  
The Subject ◽  
The Impact

Traffic flow characteristics have a significant impact on occurrence risk of road crash. The most important characteristics of the traffic flow, the impact of which is the subject of numerous studies, are the traffc flow, density, average traffic flow speed, dispersion of traffic flow speeds, as well as the contents of vehicle in traffic flow. These characteristics are in strong correlation between each other, so changes in one parameter conditional make change of other parameters. Research shows that speed-related traffic flow parameters have a significant impact on occurrence risk of road crash. Therefore, in this study an analysis of the impact of the change in the average speed of the traffic flow on the risk of an accident occurred. The research includes a section of the single carriageway from Preljina to Ljig. After the construction of the highway in the stated section of the signle carriageway, a change in the characteristics of the traffic flow occurred, with this study examining the impact of changing the average speed of the traffic flow to the occurrence risk of road crash. The connection between the speed of traffic flow and the risk of accidents has been confirmed in this study, so with the increase in average speed the risk of accidents increases.

scholarly journals THE COMPARISON OF ROAD CAPACITY OF GREENSHIELD MODEL, GREENBERG MODEL AND UNDERWOOD MODEL TOWARD MKJI 1997 CALCULATION ON THE JENDRAL SUDIRMAN ROAD, BATANG

Pondasi ◽  
2019 ◽  
Vol 24 (1) ◽  
pp. 30
Author(s):  
Farhan Sholahudin ◽  
Abdul Rochim
Keyword(s):  
Traffic Flow ◽  
Flow Characteristics ◽  
Flow Theory ◽  
Flow Speed ◽  
Traffic Flow Theory ◽  
The Road ◽  
Road Capacity ◽  
Estimation Capacity ◽  
Capacity Calculation ◽  
Traffic Behavior

Jendral Sudirman road is one of the streets in Batang Regency which has function as primary artery and it has main access to connect vital locations. It makes Jendral Sudirman road has several transportation problems. In the planning, design and establishment of various transportation system policies, traffic flow theory of movement has very important role. To facilitate the application of traffic flow theory of movement used a mathematical approach which was used to analyze the phenomenon that took place in the traffic flow. One of approach ways to comprehend the traffic behavior was by verifying it into mathematical and graphics relationships with observing to the relationship among the speed (S), density (D) and volume (V) traffic.The objective of this study was to determine traffic flow characteristics on Jendral Sudirman Road consisting of three (3) main parameters such as volume, speed and density by using mathematical models included Greenshield, Greenberg and Underwood Model. In addition, this study also aimed to determine the results of a comparison of one of the chosen model with the road capacity calculation based on MKJI 1997.Based on the data analysis  by using Greenshield model, it was known that the characteristics of the traffic on Jendral Sudirman road values obtained free flow speed (Sf)= 45.53 km/h, density jam (Dj)= 38.31 unit/km and maximum volume or road capacity(Vmax)= 1774.25 unit/hour. The estimation result of model was calculated using Greenshield model and estimation capacity calculations of MKJI 1997 had a difference about 15.49%. This could be evidence that generalize the use of manual book as MKJI 1997 in estimating the value of a certain road location capacity without researching driver behavior, vehicle characteristics and the environment of the road would be at risk in the capacity estimation results obtained. Therefore, the use of existing guidelines such as the 1997 MKJI needs carefulness in assessing the environmental condition of the road and traffic characteristics.Keywords : TrafficCharacteristic, Volume, Speed, Density, Greenshield, Greenberg, Underwood

scholarly journals The influence of the construction of raised pedestrian crossing on traffic conditions on urban segments

2020 ◽  
Vol 72 (08) ◽  
pp. 681-691
Keyword(s):  
Traffic Flow ◽  
Vehicle Speed ◽  
Driver Behaviour ◽  
Research Results ◽  
Traffic Conditions ◽  
Street Networks ◽  
Yield Rate ◽  
Flow Parameters ◽  
Pedestrian Crossing ◽  
Rate Research

One of solutions that is often used in recent times in street networks is vertical shift in pavement level at mid-block pedestrian crossings. This measure is aimed at reducing vehicle speed and increasing the motorist yield rate. Research results about the influence of raised mid-block pedestrian crossings on pedestrian and driver behaviour are presented through analysis of traffic flow parameters. The research was conducted at a mid-block signalised pedestrian crossing prior to and after rehabilitation of that crossing.

scholarly journals Impacts of Snowy Weather Conditions on Expressway Traffic Flow Characteristics

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Jiancheng Weng ◽  
Lili Liu ◽  
Jian Rong
Keyword(s):  
Traffic Flow ◽  
Traffic Management ◽  
Control Strategies ◽  
Flow Characteristics ◽  
Weather Conditions ◽  
Service Levels ◽  
The Road ◽  
Adverse Weather ◽  
Snow Conditions ◽  
The Impact

Snowy weather will significantly degrade expressway operations, reduce service levels, and increase driving difficulty. Furthermore, the impact of snow varies in different types of roads, diverse cities, and snow densities due to different driving behavior. Traffic flow parameters are essential to decide what should be appropriate for weather-related traffic management and control strategies. This paper takes Beijing as a case study and analyzes traffic flow data collected by detectors in expressways. By comparing the performance of traffic flow under normal and snowy weather conditions, this paper quantitatively describes the impact of adverse weather on expressway volume and average speeds. Results indicate that average speeds on the Beijing expressway under heavy snow conditions decrease by 10–20 km/h when compared to those under normal weather conditions, the vehicle headway generally increases by 2–4 seconds, and the road capacity drops by about 33%. This paper also develops a specific expressway traffic parameter reduction model which proposes reduction coefficients of expressway volumes and speeds under various snow density conditions in Beijing. The conclusions paper provide effective foundational parameters for urban expressway controls and traffic management under snow conditions.

Research and Improvement of the Keep-Right-Except-to-Pass Rule

2014 ◽  
Vol 915-916 ◽  
pp. 459-463
Author(s):  
He Quan Zhang
Keyword(s):  
Fluid Mechanics ◽  
Traffic Flow ◽  
Influence Factors ◽  
Traffic Model ◽  
Light Traffic ◽  
The Road ◽  
Model Based ◽  
Light Passing ◽  
Improved Model ◽  
The Impact

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.

scholarly journals Developing a New Spatial Unit for Macroscopic Safety Evaluation Based on Traffic Density Homogeneity

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Chen Wang ◽  
Lin Liu ◽  
Chengcheng Xu
Keyword(s):  
Traffic Flow ◽  
Traffic Control ◽  
Flow Characteristics ◽  
Traffic Density ◽  
Minimization Method ◽  
Spatial Unit ◽  
Flow Parameters ◽  
Safety Knowledge ◽  
Traffic Operation ◽  
Crash Modeling

Macrolevel crash modeling has been extensively applied to investigate the safety effects of demographic, socioeconomic, and land use factors, in order to add safety knowledge into traffic planning and policy-making. In recent years, with the increasing attention to regional traffic management and control, the safety effects of macrolevel traffic flow parameters may also be of interest, in order to provide useful safety knowledge for regional traffic operation. In this paper, a new spatial unit was developed using a recursive half-cut partitioning procedure based on a normalized cut (NC) minimization method and traffic density homogeneity. Two Bayesian lognormal models with different conditional autoregressive (CAR) priors were applied to examine the safety effects of traffic flow characteristics at the NC level. It was found that safety effects of traffic flow exist at such macrolevel, indicating the necessity of considering safety for regional traffic control and management. Furthermore, traffic flow effects were also examined for another two spatial units: Traffic Analysis Zone (TAZ) and Census Tract (CT). It was found that ecological fallacy and atomic fallacy could exist without considering traffic flow parameters at those planning-based levels. In general, safety needs to be considered for regional traffic operation and the effects of traffic flow need to be considered for spatial crash modeling at various spatial levels.

scholarly journals KAJIAN KINERJA PERSIMPANGAN TIDAK BERSINYAL (STUDI KASUS : PERSIMPANGAN TIGA GADUT, JALAN RAYA INDARUNG – BANDAR BUAT, KOTA PADANG)

2019 ◽  
Vol 2 (2) ◽  
Author(s):  
Eko Prayitno ◽  
Veronika Veronika
Keyword(s):  
Traffic Flow ◽  
Environmental Data ◽  
Degree Of Saturation ◽  
Road User ◽  
Total Delay ◽  
The Road ◽  
Traffic Conditions ◽  
Road Capacity ◽  
Side Friction Factor ◽  
Side Friction

The highway is one of the infrastructure for the smooth traffic. One part of the road that are considered necessary to be analyzed and evaluated is an intersection. Three Gadut intersection is non signalized intersection. The traffic flow is quite dense, and lack of discipline of road user factors competing space to pass the crossing, resulting in congestion is very influential on traffic conditions at peak hours in the morning, afternoon and evening. Prior to conducting the survey, the first to do is survey the condition of the intersection that includes geometric characteristics and traffic volume. From the analysis of environmental data, side friction factor to the junction of three Gadut is the criteria being. Rated capacity (C) the smallest is 3706.3 smp/hour, the degree of saturation of 1.1 smp/hour. This value is over the limit permitted values manually indonesian road capacity of 0.8 to 0.9 (1.1> 0.9), it is concluded that the traffic flow is the crossroads of three Gadut saturated traffic flow. The queue probability value between 128.8% - 157.4% with a total delay largest average 11.57 seconds/smp. It is concluded that the chances of a queue at the intersection of three Gadut very large, so it could cause congestion.

scholarly journals Evaluating Impacts of Overloaded Heavy Vehicles on Freeway Traffic Condition by a Novel Multi-Class Traffic Flow Model

2018 ◽  
Vol 10 (12) ◽  
pp. 4694 ◽  
Author(s):  
Xiang Wang ◽  
Po Zhao ◽  
Yanyun Tao
Keyword(s):  
Traffic Flow ◽  
Flow Model ◽  
Management Strategies ◽  
Maximum Speed ◽  
Heavy Vehicles ◽  
Fundamental Diagram ◽  
Traffic Condition ◽  
Traffic Flow Model ◽  
Traffic Conditions ◽  
The Impact

Overloaded heavy vehicles (HVs) have significant negative impacts on traffic conditions due to their inferior driving performance. Highway authorities need to understand the impact of overloaded HVs to assess traffic conditions and set management strategies. We propose a multi-class traffic flow model based on Smulders fundamental diagram to analyze the influence of overloaded HVs on traffic conditions. The relationship between the overloading ratio and maximum speed is established by freeway toll collection data for different types of HVs. Dynamic passenger car equivalent factors are introduced to represent the various impacts of overloaded HVs in different traffic flow patterns. The model is solved analytically and discussed in detail in the appendices. The model validation results show that the proposed model can represent traffic conditions more accurately with consideration for overloaded HVs. The scenario tests indicate that the increase of overloaded HVs leads to both a higher congestion level and longer duration.

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