Improving the Intelligent Driver Model by Incorporating Vehicle Dynamics: Microscopic Calibration and Macroscopic Validation
Dominik Salles, Steve Oswald, Hans-Christian Reuss
TL;DR
This work addresses the challenge of accurately calibrating microscopic car-following models to reproduce real urban driving behavior and its macroscopic consequences. It extends the Intelligent Driver Model with vehicle-dynamics-based equations (EIDM) and calibrates it against drone-derived trajectories using differential evolution, demonstrating superior microscopic fit and the emergence of realistic macroscopic phenomena such as capacity drop and stop-and-go waves. The results show that EIDM outperforms the standard IDM and Krauss models, and that incorporating dynamics yields additional gains in fidelity. The study provides a practical calibration framework and open-source tools, enabling more reliable city-scale traffic simulations for evaluating infrastructure and automated-vehicle technology scenarios.
Abstract
Microscopic traffic simulations are used to evaluate the impact of infrastructure modifications and evolving vehicle technologies, such as connected and automated driving. Simulated vehicles are controlled via car-following, lane-changing and junction models, which are designed to imitate human driving behavior. However, physics-based car-following models (CFMs) cannot fully replicate measured vehicle trajectories. Therefore, we present model extensions for the Intelligent Driver Model (IDM), of which some are already included in the Extended Intelligent Driver Model (EIDM), to improve calibration and validation results. They consist of equations based on vehicle dynamics and drive off procedures. In addition, parameter selection plays a decisive role. Thus, we introduce a framework to calibrate CFMs using drone data captured at a signalized intersection in Stuttgart, Germany. We compare the calibration error of the Krauss Model with the IDM and EIDM. In this setup, the EIDM achieves a 17.78 % lower mean error than the IDM, based on the distance difference between real world and simulated vehicles. Adding vehicle dynamics equations to the EIDM further improves the results by an additional 18.97 %. The calibrated vehicle-driver combinations are then investigated by simulating the traffic in three different scenarios: at the original intersection, in a closed loop and in a stop-and-go wave. The data shows that the improved calibration process of individual vehicles, openly available at https://www.github.com/stepeos/pycarmodel_calibration, also provides more accurate macroscopic results.
