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Author

Gitakrishnan Ramadurai

Bio: Gitakrishnan Ramadurai is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Traffic flow & Bottleneck. The author has an hindex of 17, co-authored 61 publications receiving 1108 citations. Previous affiliations of Gitakrishnan Ramadurai include Rensselaer Polytechnic Institute & Indian Institutes of Technology.


Papers
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Journal ArticleDOI
TL;DR: In this article, the link of land use and road design on pedestrian safety and the effect of the level of spatial aggregation on the frequency of pedestrian accidents was investigated for New York City based on an extensive dataset collected from different sources over a period of 5 years.

222 citations

Journal ArticleDOI
TL;DR: A method and results on sensitivity analysis and automatic calibration of VISSIM model using data from an intersection in Chennai has heavy flows during the peak time and Genetic Algorithm was used to find the optimal combination of sensitive parameters during calibration.

89 citations

Journal ArticleDOI
TL;DR: The authors formulates the dynamic equilibrium conditions for a single bottleneck model with heterogeneous commuters as a linear complementarity problem and presents theoretical proofs for solution existence and uniqueness, and numerical results and insights for different heterogeneity assumptions.
Abstract: This paper formulates the dynamic equilibrium conditions for a single bottleneck model with heterogeneous commuters as a linear complementarity problem. This novel formulation offers a formal framework for the rigorous study and solution of a single bottleneck model with general heterogeneity parameter assumptions, enabling the adoption of well established complementarity theory and methods to analyze the model, and providing a significant contribution to the existing literature that either lacks a rigorous formulation or solves the problem under a limited set of heterogeneity parameter assumptions. The paper presents theoretical proofs for solution existence and uniqueness, and numerical results and insights for different heterogeneity assumptions.

87 citations

Journal ArticleDOI
TL;DR: A new approach-robust system optimal signal control model is proposed; a supply-side within day operational transportation model where future transportation demand is assumed to be uncertain and a robust dynamic system optimal model with an embedded cell transmission model is formulated.

84 citations

Journal ArticleDOI
TL;DR: In this paper, the authors analyzed changes in sociodemographic, activity, land use, and mobility patterns and their effects on travel dimensions in the context of a developing country.
Abstract: This study analyzes changes in sociodemographic, activity, land use, and mobility patterns and their effects on travel dimensions in the context of a developing country. More specifically, increase in vehicle ownership (both two-wheelers and cars) and changes in mode choice over time are observed and analyzed with the use of household data from Chennai, India. Three sources of dynamics are analyzed: exogenous variable dynamics, sensitivity changes over time, and the influence of lagged and persistent effects. The key drivers of growth in travel demand include the increase in vehicle ownership, the number of workers, and the increase in female drivers. The influence of social and technological factors on vehicle ownership and mode choice such as peer pressure and mobile phone ownership are also significant. In addition, the effect of land use, accessibility, and activity has been investigated. Results show significant evidence of differences in travel decisions across different user segments (on the basis ...

70 citations


Cited by
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11 Feb 2010
TL;DR: The American Community Survey (ACS) as discussed by the authors has been conducted on an ongoing basis for the entire country since 2005 and has been shown to be more accurate than the traditional decennial census.
Abstract: Historically, most demographic data for states and substate areas were collected from the long version of the decennial census questionnaire. A “snapshot” of the characteristics of the population on the April 1 census date was available once every 10 years. The long form of the decennial census has been replaced by the American Community Survey (ACS) that has been conducted on an ongoing basis for the entire country since 2005. Instead of a snapshot in which all of the data are gathered at one time, the ACS aggregates data collected over time, making the results more difficult to interpret. However, the ACS data are updated annually.

691 citations

Book
01 Jan 1997
TL;DR: This book presents a coherent approach to the analysis of transportation networks based on the concept of network equilibrium and the application of convex programming methods, and indicates promising areas for further research.
Abstract: Transportation Networks. Optimality. Cost Functions. Deterministic User Equilibrium Assignment. Stochastic User Equilibrium Assignment. Trip Table Estimation. Network Reliability. Network Design. Conclusions. References. Index.

584 citations

Journal ArticleDOI
TL;DR: In this paper, a linear programming formulation for autonomous intersection control (LPAIC) is proposed to account for traffic dynamics within a connected vehicle environment, where a lane based bi-level optimization model is introduced to propagate traffic flows in the network, accounting for dynamic departure time, dynamic route choice, and autonomous intersections control in the context of system optimum network model.
Abstract: This paper develops a novel linear programming formulation for autonomous intersection control (LPAIC) accounting for traffic dynamics within a connected vehicle environment. Firstly, a lane based bi-level optimization model is introduced to propagate traffic flows in the network, accounting for dynamic departure time, dynamic route choice, and autonomous intersection control in the context of system optimum network model. Then the bi-level optimization model is transformed to the linear programming formulation by relaxing the nonlinear constraints with a set of linear inequalities. One special feature of the LPAIC formulation is that the entries of the constraint matrix has only {−1, 0, 1} values. Moreover, it is proved that the constraint matrix is totally unimodular, the optimal solution exists and contains only integer values. It is also shown that the traffic flows from different lanes pass through the conflict points of the intersection safely and there are no holding flows in the solution. Three numerical case studies are conducted to demonstrate the properties and effectiveness of the LPAIC formulation to solve autonomous intersection control.

216 citations