scholarly journals Space Occupancy Method for Estimation of PCUs of Vehicles at Different Speed and Flow Ranges on Urban Road

2019 ◽  
Vol 11 (02) ◽  
pp. 77-84
Author(s):  
S. Srikanth
Keyword(s):  
Heterogeneous Traffic ◽  
Vehicle Dynamic ◽  
Passenger Cars ◽  
Projected Area ◽  
Traffic Condition ◽  
Urban Road ◽  
Data Space ◽  
Speed Flow ◽  
Different Types ◽  
Road Space

The problem of quantification of volume under heterogeneous traffic has been addressed by converting the different types of vehicles into equivalent passenger cars and expressing the volume or capacity of roads in terms of PCU per hour. The traffic movement under heterogeneous traffic condition differs, however, significantly from that of homogeneous traffic in respect of the pattern of occupancy of road space by vehicles. Video graphic technique was used for the traffic flow data collection. A Traffic Enumeration Software was used for extracting speed, flow and headway data. Space occupancy method was used for PCU determination where in the space headway of each vehicle was also taken into consideration along with the projected area of the vehicle. Dynamic PCU values of different vehicles were found out corresponding to both speed and flow ranges. Reliability of dynamic PCU values of different vehicles is also determined by using density.

LATERAL MOVEMENT OF VEHICLES UNDER WEAK-LANE DISCIPLINE HETEROGENEOUS TRAFFIC

2016 ◽  
Vol 78 (4) ◽  
Author(s):  
Geetimukta Mahapatra ◽  
Akhilesh Kumar Maurya ◽  
Anil Minhans
Keyword(s):  
Vehicle Dynamics ◽  
Important Variable ◽  
Heterogeneous Traffic ◽  
Lateral Acceleration ◽  
Initial Increase ◽  
Lateral Movement ◽  
Traffic Condition ◽  
Safe Driving ◽  
Different Types ◽  
Road Geometry

Safe driving can be achieved by prevention of risky situations which requires the knowledge of the vehicle dynamics and road geometry. The Indian traffic condition is heterogeneous in nature and has weak lane discipline. Hence, vehicles interactions takes place laterally also along with their longitudinal interaction. Vehicles lateral movements (interactions) are quite high due to absence of lane discipline. Therefore, the lateral acceleration of vehicles are an important variable which characterizes the corresponding vehicle dynamics. Several studies have been done by various authors on lateral acceleration in curves, however, lateral movement study of vehicles on straight road section is also important to analyze vehicles’ maneuver in such traffic (i.e. traffic stream with weak lane discipline). Therefore, the present study is about the observation of lateral movements of vehicles over different types of roads in three metropolitan cities of India (Kolkata, Mumbai and Pune) under moderate traffic conditions. Lateral acceleration variation of five different types of vehicles (SUV cars, Sedan cars, Hutch Back cars, motorized three wheeler and two wheeler) have been recorded to investigate its relationship with vehicles longitudinal characteristics (i.e. longitudinal speed) in Indian heterogeneous and weak lane disciplined traffic. Lateral acceleration values quickly rises with initial increase in speed afterward lateral acceleration values reduces with further increase in vehicles longitudinal speed.  Impact of vehicle type and locations on the lateral maneuvering of vehicles have also been studied

The Analysis of Urban Road Traffic State Based on Kinds Floating Car Data

2014 ◽  
Vol 694 ◽  
pp. 80-84
Author(s):  
Xiao Tong Yin ◽  
Chao Qun Ma ◽  
Liang Peng Qu
Keyword(s):  
Road Traffic ◽  
Velocity Estimation ◽  
Least Square ◽  
Single Type ◽  
Estimation Model ◽  
Average Speed ◽  
Urban Road ◽  
Traffic State ◽  
Floating Car Data ◽  
Different Types

The analysis of the unban road traffic state based on kinds of floating car data, is based on the model and algorithm of floating car data preprocessing and map matching, etc. Firstly, according to the characteristics of the different types of urban road, the urban road section division has been carried on the elaboration and optimization. And this paper introduces the method of calculating the section average speed with single floating car data, also applies the dynamic consolidation of sections to estimate the section average velocity.Then the minimum sample size of floating car data is studied, and section average velocity estimation model based on single type of floating car data in the different case of floating car data sample sizes has been built. Finally, the section average speed of floating car in different types is fitted to the section average car speed by the least square method, using section average speed as the judgment standard, the grade division standard of urban road traffic state is established to obtain the information of road traffic state.

scholarly journals Factors related to the increasing number of seriously injured cyclists and pedestrians in a Swedish urban region 2003–17

2019 ◽  
Vol 42 (2) ◽  
pp. e158-e164 ◽  
Author(s):  
Astrid Värnild ◽  
Per Tillgren ◽  
Peter Larm
Keyword(s):  
Road Safety ◽  
Urban Region ◽  
Elderly Persons ◽  
Urban Road ◽  
Road Space ◽  
Accident Data ◽  
Serious Injury ◽  
National Road ◽  
Serious Injuries ◽  
Vision Zero

Abstract Background The number of seriously injured unprotected road users has increased during implementation of a road safety policy Vision Zero. The aim of the study is to identify factors associated with the increase in serious injuries among cyclists and pedestrians (even single pedestrian accidents) that occurred in an urban road space in a Swedish region 2003–17. The urban road space includes roads, pavements and tracks for walking and cycling. Methods Data were retrieved from STRADA (Swedish Traffic Accident Data Acquisition) and NVDB (National Road Database). Descriptive statistics and logistic regression with odds ratios for sex, age and part of road space were assessed. Results The number of seriously injured cyclists and pedestrians more than doubled from 2003 to 2017, with the greatest increase for pedestrians. Older age increased the probability of serious injury since 2012 for the group ≥ 80 years and since 2015 for the group 65–79 years. No significant effect of sex. Most injuries occur in areas not transformed by Vision Zero. Conclusions An increasing number of elderly persons in the generation born in the 1940s and increased life expectancy are important factors. There is a need to increase road safety measures that also promote active mobility.

An Approach Based on Generic Label Correcting Algorithm for Supply Chain Modeling

2013 ◽  
Vol 411-414 ◽  
pp. 2085-2088
Author(s):  
Xiao Qing Geng ◽  
Yu Wang
Keyword(s):  
Supply Chain ◽  
Set Theory ◽  
Rough Set ◽  
Rough Set Theory ◽  
Decision Rules ◽  
Data Space ◽  
Different Types ◽  
Supply Chain Modeling

In this paper, the rough set theory is applied to reduce the complexity of data space and to induct decision rules. It proposes the generic label correcting (GLC) algorithm incorporated with the decision rules to solve supply chain modeling problems. This proposed approach is agile because by combining various operators and comparators, different types of paths in the reduced networks can be solved with one algorithm.

scholarly journals Study on the Annual Reduction Rate of Vehicle Emission Factors for Carbon Monoxide: A Case Study of Urban Road Tunnels in Shenzhen, China

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Weiwei Liu ◽  
Jianxun Chen ◽  
Yanbin Luo ◽  
Zhou Shi ◽  
Xiang Ji ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Reduction Rate ◽  
Emission Factors ◽  
Pollutant Emission ◽  
Passenger Cars ◽  
Urban Road ◽  
Road Tunnels ◽  
Measurement Results ◽  
Annual Reduction ◽  
Co Emission

Environmental pollution and energy conservation in urban tunnels have become important issues that affect the scientific design and sustainable development of urban tunnels. The carbon monoxide (CO) concentration in urban road tunnels is regarded as a direct reflection and a useful tracer of the intensity of anthropogenic transportation activities. Previous studies in recent years have paid more attention to pollutant emission factors, but less to the calculation parameters of ventilation design for tunnels. This paper aims to study a reasonable annual reduction rate of CO base emission factors. Therefore, a detailed field measurement was carried out in the four typical urban road tunnels, Henglongshan Tunnel, Cejiexian Tunnel, Jiuweiling Tunnel, and Dameisha Tunnel in Shenzhen, China, from March 29 to September 16, 2014. Measurement results showed that the traffic flow of the four urban tunnels had been approaching the design value, or even beyond the limit. The average daily air velocities in the four tunnels were all within 5 m/s, whereas the maximum air velocity had exceeded the limit of 10 m/s. The CO concentrations in Henglongshan Tunnel, Cejiexian Tunnel, Jiuweiling Tunnel, and Dameisha Tunnel were 17 ppm, 7 ppm, 39 ppm, and 8 ppm, respectively. Moreover, it was found that the average CO emission factors of Henglongshan Tunnel, Cejiexian Tunnel, Jiuweiling Tunnel, and Dameisha Tunnel were 1.075 g/(km·veh), 1.245 g/(km·veh), 4.154 g/(km·veh), and 1.739 g/(km·veh), respectively. Based on the statistical data, the CO emission factors of mixed traffic and passenger cars decrease by an average of 16.4% and 33.3%, respectively, per year through the regression method and by an average of 17.4% and 29.0%, respectively, per year through the extremum method. Finally, when considering the safety factor of 20%, it is more reasonable for the CO base emission to adopt 4% as an annual reduction rate for ventilation design in urban tunnels.

Saturation Flow Model for Signalized Intersection under Mixed Traffic Condition

2018 ◽  
Vol 2672 (15) ◽  
pp. 55-65 ◽  
Author(s):  
Sabyasachi Biswas ◽  
Souvik Chakraborty ◽  
Indrajit Ghosh ◽  
Satish Chandra
Keyword(s):  
Conventional Method ◽  
Detailed Comparison ◽  
Heterogeneous Traffic ◽  
Signalized Intersection ◽  
Percentage Error ◽  
Mixed Traffic ◽  
Kriging Method ◽  
Traffic Condition ◽  
Saturation Flow ◽  
The Impact

Saturation flow is one of the most important functional parameters at signalized intersections. It is to be noted that saturation flow is a functional measure of the intersection operation, which indicates the probable capacity if working in an ideal situation. However, determination of the saturation flow is a challenging task in developing countries like India where vehicles with diverse static and dynamic characteristics use the same carriageway. At the same time, it is influenced by several other factors. In this context, the present research is carried out to examine the effects of traffic composition, approach width and right-turning movements on saturation flow under heterogeneous traffic conditions. This paper proposes a model for computing saturation flow at the signalized intersection under mixed traffic condition based on Kriging approach. A detailed comparison of the mean saturation flow values obtained by the conventional method, regression method, and Kriging method has also been presented. Low mean absolute percentage error values (<5%) have been obtained for saturation flow by Kriging method with respect to the conventional method. Finally, the proposed models are used to evaluate the impact of right-turning vehicles on saturation flow under shared lane condition.

scholarly journals Concept of queue clearance rate for estimation of equivalency factors at priority junctions

2016 ◽  
Vol 43 (7) ◽  
pp. 593-598 ◽  
Author(s):  
Mithun Mohan ◽  
Satish Chandra
Keyword(s):  
Developing Countries ◽  
Clearance Rate ◽  
Developed Countries ◽  
Traffic Volume ◽  
Heterogeneous Traffic ◽  
Passenger Cars ◽  
Passenger Car ◽  
Traffic Conditions ◽  
Equivalency Factors ◽  
Equivalent Number

Traffic in developing countries is often distinguished from others for its diversity in vehicular composition and passenger car equivalents (PCE) becomes essential in such conditions for expressing traffic volume in terms of equivalent number of passenger cars. The PCE estimation at two-way stop-controlled intersections in developing countries is further complicated by the lack of movement priority and lane discipline. The study introduces a method to find PCE factors based on the time taken by a queue of vehicles to completely clear the intersection and composition of the queue. The method is validated through simulations in VISSIM software and was then used to derive PCE factors for three intersections in India. Although the method is developed and tested to estimate PCE factors under highly heterogeneous traffic at priority junctions in India, it is quite general in nature and can be used in traffic conditions found in developed countries as well.

scholarly journals Capacity Estimation of Multilane Highways under Heterogeneous Traffic Conditions using Micro-Simulation Technique

2020 ◽  
Vol 12 (01) ◽  
pp. 20-25
Author(s):  
Tanumoy Ghosh ◽  
Sudip Kumar Roy ◽  
Subhamay Gangopadhyay
Keyword(s):  
Simulation Model ◽  
Traffic Flow ◽  
Flow Characteristics ◽  
Simulation Models ◽  
Heterogeneous Traffic ◽  
Traffic Condition ◽  
Traffic Conditions ◽  
Geometric Conditions ◽  
Micro Simulation ◽  
Traffic Flow Characteristics

The behavior of a driver of any vehicle is important in estimating heterogeneous traffic conditions with no strict lane discipline. In the present study, a micro-simulation model is used to analyze the mixed traffic condition with different drivers’ behavior parameters. The field data collected on traffic flow characteristics of multilane highways are used in the calibration and validation of the simulation model. Out of the ten coefficient of correlation (CC) parameters in the simulation model, five are used in the present study to make a model of simulation for heterogeneous traffic; the other five parameters are not considered for testing their influence on simulated capacity values as they represent very typical behavior of a driver, either in car-following, or in free-flow conditions. Two separate simulation models are made by changing the CC (CC0, CC1, CC2, CC7, and CC8) parameters, each for a four-lane divided and a six-lane divided highway as the geometric conditions of the roads and the traffic flow is different for both the cases. These models are then applied on two other sections of a four-lane divided and a six-lane divided highway to validate the parameters of the model developed earlier for other sections.

scholarly journals MULTIPLE ACCESS TECHNIQUES FOR 5G NETWORKS

2020 ◽  
Vol 5 (2) ◽  
pp. 305-314
Author(s):  
Mrs. Rinkoo Bhatia
Keyword(s):  
Multiple Access ◽  
Heterogeneous Traffic ◽  
5G Networks ◽  
Comprehensive Overview ◽  
Fifth Generation ◽  
Power Domain ◽  
Different Types ◽  
Code Domain ◽  
Multiple Access Schemes ◽  
Multiple Domains

Fifth generation (5G) wireless networks face various challenges in order to support largescale heterogeneous traffic and users, therefore new modulation and multiple access (MA) schemes are being developed to meet the changing demands. As this research space is ever increasing, it becomes more important to analyze the various approaches, therefore, in this article we present a comprehensive overview of the most promising Multiple Access schemes for 5G networks. Our article focuses on various types of non-orthogonal multiple access (NOMA) techniques. Specifically, we first introduce different types of modulation schemes, potential for OMA. We then pay close attention to various types of NOMA candidates, including power-domain NOMA, code-domain NOMA, and NOMA multiplexing in multiple domains. From this exploration, we can identify the opportunities and challenges that will have the most significant impacts on modulation and MA designs for 5G networks.

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