Calibration and Validation of Microscopic Simulation Model of Ambedkar Statue Junction Based on VISSIM

Abstract

VISSIM has become one of the most useful and reliable programs utilized by contemporary engineers and researchers in the processes of evaluation of control operations and strategies of transportation. In this study calibration and validation techniques of VISSIM parameters that derive from the need to accurately match the simulations results of the models with the observed field data. Micro-simulation is a widely used and one of the most effective ways to predict traffic behavior of urban intersections. The advanced microscopic traffic simulator is PTV VISSIM. It has been used to evaluate the peak-hour traffic operating conditions to replicate the total scenario several local vehicles are modelled. The model was duly calibrated using field data and validated using Geoffrey E. Heavers (GEH) statistics comparisons or GEH values, F-Distribution, T-distribution and Chi-squared test. A key component of simulation modeling is the calibration and validation stage of the model building process. Calibration is defined as the adjustment of computer simulation model parameters to accurately reflect prevailing conditions of the roadway network. Validation is defined as the process of comparing simulated model results with field measurements in order to determine the accuracy of the simulation model. In a metropolitan city of a developing country, for instance Ambedkar Statue Junction model has been calibrated from the actual field data and using the outcome the total speed and volume for an intersection of that corridor was estimated.

Introduction

Traffic growth in large cities of developing countries poses significant challenges for traffic engineers, making traffic consideration essential in urban planning. Simulation, especially microscopic traffic simulation, is an effective and safe tool to analyze traffic operations and forecast the impact of new developments on road networks. A critical part of simulation modeling is calibrating and validating models to ensure accuracy by aligning simulated data with real-world traffic observations.

This study focuses on the Ambedkar Statue Junction in Hyderabad, India, a key intersection near Hussainsagar Tank bund and Telugu Thalli flyover. The research objectives include collecting physical features and traffic data of the junction, estimating peak hour volumes and vehicle compositions, improving intersection design using AutoCAD, and validating traffic models statistically.

The methodology involved collecting traffic volume counts for all approach roads, refining the intersection design, and calibrating a VISSIM microscopic simulation model. The calibrated model was validated against independent field data using statistical tests such as GEH statistics, Chi-squared test, F-distribution, and T-distribution to assess goodness of fit and significance of differences between observed and simulated traffic volumes.

Key results showed good fit in GEH statistics for most approaches, while Chi-squared test indicated some lack of fit, and F-distribution suggested significant differences in certain runs. Overall, the study demonstrated the utility of microscopic traffic simulation and rigorous statistical validation to analyze and improve traffic conditions at complex urban intersections in developing countries.

Conclusion

Ambedkar statue was selected for concluding various parameters. On the basis of on-site traffic data collection the peak hour volume, peak hour timing and vehicular composition of Ambedkar statue junction were calculated • Peak Hour Volume: The peak hour volume for Liberty to Tank bund was found to be 3150 veh/hr • Peak Hour flow: The peak hour Timings for Liberty to Tank Bund was found to be 10:00-11:00 AM A. Vehicular Composition Vehicle composition for 2-wheelers, 3-wheelers, cars, buses are as follows: 2-wheelers were observed to be 54% to 64%, 3-wheelers were 5% to 15%, Cars were 22% to 36%, and Buses were 3% to 5% The volume of the Ambedkar statue Junction is calibrated and validated by using the following four methods and is checked for goodness of fit 1) GEH Statistics: The GEH values varies from 1.73 to 3.78 for peak hour traffic flow.The GEH values varies from 1.34 to 2.10 for non peak hour traffic flow.Observed traffic with simulated traffic data is used to calculate GEH values of the AMBEDKAR STATUE JUNCTION inVISSIM .The GEH values are less than 5.0 which indicate good fit.The difference between the observed and simulated traffic volume varies from 12.79% to 34.78 % for peak hour flow.For non peak hour flow the difference varies from 7.50 % to 32.48% Therefore,the GEH statistics is recommended for further statistical studies 2) CHI-Squared Test: From the observed and simulated data . ?2 (observed) > ?2 (critical) the observed data do not show good fit. Therefore, it is not recommended for further studies 3) F-Distribution: From the observed and simulted data. F(Simulated) > Fi(Observed), therefore the difference is significant. Therefore ,the F-Distribution indicate good fit.It is recommended for further statistical studies 4) T-Distribution: From the observed and simulated data. T (Simulated) > Ti(Observed) ,therefore the difference is significant. The T-Distribution indicate good fit. It is recommended for further statistical studies

References

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Copyright

Copyright © 2025 Mrs. Soniya Grace. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.