Browsing by Author "Raj, P."

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    Assessment of Impact of Roadside Bus-Stops on Capacity of Urban Divided Roads Using Microscopic Simulation Model
    (Springer Science and Business Media Deutschland GmbH, 2022) Raj, P.; Asaithambi, G.; Ravi Shankar, A.U.
    In developing countries, traffic congestion is not only due to substantial vehicular growth but also due to many roadside activities which affects the performance of roads. Among the various roadside activities, the presence of bus-stops has a significant influence on capacity of roads as the demand of public transport buses in urban areas of developing countries is relatively high. Researchers have attempted to study the impact of bus-stops on traffic flow characteristics. However, limited attempts have been made to study the influence of bus-stops on capacity using simulation models under mixed traffic. Thus, this study aims to assess the impact of roadside bus-stops on capacity of roads using a microscopic simulation model developed specifically for urban divided roads. The validated model was then applied to study the impact of bus-stop on capacity of urban roads. The percentage reduction in capacity due to the influence of bus-stop was obtained by performing sensitivity analysis by varying bus proportion. This study finds interesting applications in developing standards related to capacity estimation and reduction due to side frictions in Indian traffic. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.
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    Effect of curbside bus stops on passenger car units and capacity in disordered traffic using simulation model
    (Taylor and Francis Ltd., 2022) Raj, P.; Asaithambi, G.; Ravi Shankar, A.U.
    Representation of traffic in terms of Passenger Car Unit (PCU) is imperative to estimate capacity in disordered traffic. Many studies have been conducted on investigation of impacts of traffic and geometric conditions on traffic characteristics and PCUs. However, the sensitivity of PCUs due to roadside frictions are not adequately studied. To address this gap, this study aims to estimate PCU values for vehicles under the influence of curbside bus stop, which is the most common roadside friction in developing countries. Lack of space for providing exclusive bus bays and higher demand for public transport buses in urban roads justify the need for this study. Methodology of this study involves development and validation of a microscopic simulation model to quantify the impact of curbside bus stop on PCU as well as capacity. The results indicate the significant differences in PCU values due to the presence of curbside bus stop with varying traffic volume and composition. © 2020 Informa UK Limited, trading as Taylor & Francis Group.
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    Modeling lateral placement and movement of vehicles on urban undivided roads in mixed traffic: A case study of India
    (2019) Kotagi, P.B.; Raj, P.; Asaithambi, G.
    In India, the majority of urban roads are undivided where the behavior of flows in a particular direction is predominantly influenced by the opposing traffic. Due to lack of lane segregation, the vehicles in ongoing direction occupy the opposing lane, which increases the lateral interactions between vehicles. These lateral interactions are influenced by various parameters such as vehicle types, driver behavior and vehicular speeds. Study of such complex interactions plays an important role in evaluating various management measures using microscopic simulation models. The lateral characteristics of vehicles, such as placement, separation and movement, act as necessary input for simulation models. The present study aims to analyze and model the lateral characteristics of vehicles on two-lane urban undivided roads. To achieve this, traffic flow data were collected from an urban undivided mid-block section in Bangalore City, India, using video graphic technique. Multiple linear regression model was developed for predicting the lateral placement of subject vehicle and it was found that lateral placement of subject vehicle is influenced by types and speeds of subject and opposing vehicles. Lateral separation for different types of ongoing (subject) and opposing pairs was also analyzed. The results show that both the ongoing and opposing vehicles have less freedom to move laterally when their sizes increase and hence, lateral separation decreases. The choice of path of vehicles' lateral shifts (left, current and right) on urban undivided roads was modeled using multinomial logistic regression. Lateral shift of a vehicle is influenced by speeds of subject vehicle and leader vehicle in current path, speed of leader vehicle in target path, and lateral gap between leader vehicles in current path and target path. 2019 The Authors
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    Modeling lateral placement and movement of vehicles on urban undivided roads in mixed traffic: A case study of India
    (Chang'an University, 2020) Kotagi, P.B.; Raj, P.; Asaithambi, G.
    In India, the majority of urban roads are undivided where the behavior of flows in a particular direction is predominantly influenced by the opposing traffic. Due to lack of lane segregation, the vehicles in ongoing direction occupy the opposing lane, which increases the lateral interactions between vehicles. These lateral interactions are influenced by various parameters such as vehicle types, driver behavior and vehicular speeds. Study of such complex interactions plays an important role in evaluating various management measures using microscopic simulation models. The lateral characteristics of vehicles, such as placement, separation and movement, act as necessary input for simulation models. The present study aims to analyze and model the lateral characteristics of vehicles on two-lane urban undivided roads. To achieve this, traffic flow data were collected from an urban undivided mid-block section in Bangalore City, India, using video graphic technique. Multiple linear regression model was developed for predicting the lateral placement of subject vehicle and it was found that lateral placement of subject vehicle is influenced by types and speeds of subject and opposing vehicles. Lateral separation for different types of ongoing (subject) and opposing pairs was also analyzed. The results show that both the ongoing and opposing vehicles have less freedom to move laterally when their sizes increase and hence, lateral separation decreases. The choice of path of vehicles' lateral shifts (left, current and right) on urban undivided roads was modeled using multinomial logistic regression. Lateral shift of a vehicle is influenced by speeds of subject vehicle and leader vehicle in current path, speed of leader vehicle in target path, and lateral gap between leader vehicles in current path and target path. © 2019 The Authors
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    Review of Methods for Estimation of Passenger Car Unit Values of Vehicles
    (American Society of Civil Engineers (ASCE) onlinejls@asce.org 1801 Alexander Bell DriveGEO Reston VA 20191 Alabama, 2019) Raj, P.; Sivagnanasundaram, K.; Asaithambi, G.; Ravi Shankar, A.U.
    Estimation of passenger car unit (PCU) values is very important for traffic capacity analysis and other relevant applications such as level of service (LOS) measures, determination of saturation flow rate, signal design and coordination, and development of traffic flow models. Because of such wide applications, the accuracy of PCU values is highly significant in traffic flow analysis. Many research works have been carried out on estimation of PCUs in the past few decades. In developed countries, various methods were developed for estimating PCU values for different types of facilities which carry trucks and buses of lesser composition. But these methods are not completely analogous for mixed traffic due to the presence of wide variety of vehicle types, nonlane discipline, intraclass variability of vehicles and their maneuverability. With this consideration, various methods used for estimating PCUs for different facility types under homogeneous and mixed traffic conditions are reviewed and the drawbacks of the existing methods are identified in this paper. The challenges in estimating PCU values and future directions for improving the PCU estimation methods are also presented. © 2019 American Society of Civil Engineers.
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    Review of Methods for Estimation of Passenger Car Unit Values of Vehicles
    (American Society of Civil Engineers (ASCE) onlinejls@asce.org 1801 Alexander Bell DriveGEO Reston VA 20191 Alabama, 2019) Raj, P.; Sivagnanasundaram, K.; Asaithambi, G.; Ravi Shankar, A.U.
    Estimation of passenger car unit (PCU) values is very important for traffic capacity analysis and other relevant applications such as level of service (LOS) measures, determination of saturation flow rate, signal design and coordination, and development of traffic flow models. Because of such wide applications, the accuracy of PCU values is highly significant in traffic flow analysis. Many research works have been carried out on estimation of PCUs in the past few decades. In developed countries, various methods were developed for estimating PCU values for different types of facilities which carry trucks and buses of lesser composition. But these methods are not completely analogous for mixed traffic due to the presence of wide variety of vehicle types, nonlane discipline, intraclass variability of vehicles and their maneuverability. With this consideration, various methods used for estimating PCUs for different facility types under homogeneous and mixed traffic conditions are reviewed and the drawbacks of the existing methods are identified in this paper. The challenges in estimating PCU values and future directions for improving the PCU estimation methods are also presented. © 2019 American Society of Civil Engineers.
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    Simulation on Motion of a Trebuchet
    (Springer Science and Business Media Deutschland GmbH, 2022) Mulamuttal, K.B.; Kattigenahally, K.K.; Kalluvalappil, G.V.; Raj, P.; Narasimhamurthy, N.K.; Vankalkunti, S.
    In this paper, an innovative approach to analyze the performance of one of the basic mechanical system “Trebuchet†is discussed. An efficient simulation approach is developed for ‘The motion of a Trebuchet’ analysis. The developed simulation tool provides the access for all possible parametric variations so that the theoretical concepts are visualized easily by very simple simulation process. The process of development of the simulator is briefed in this paper. Simulations can be efficiently used to analyze the behavior of a Trebuchet system. For diverse patterns of control parameters, the system design can be tested using simulations and the most efficient system can be implemented in real time. Likewise, this paper explains in detail how the motion of a trebuchet is effectively analyzed using simulation by giving extreme conditional parameters. HTML, CSS and JavaScript tools are used to develop this simulation. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.