Evaluating Traffic Delay at Urban Intersections: Field Measurements vs. VISSIM Modeling (Barzani Namr Ring Road, Erbil)

Smail, Helen Sirwan; Talabany, Aso Faiz Saeed · 2025 · Crossref

DOI: 10.37649/ajes-25-015

archive: archived pipeline: cataloged verified

Get this paper ↗ (DOI — opens at the source; we link to it, we don't host it)

Summary

This study addresses the challenge of urban traffic congestion in Erbil, Iraq, specifically focusing on quantifying and modeling control delays at signalized intersections. The research was motivated by the need for accurate performance metrics to inform traffic management, as conventional analytical models often fail to capture the complexities of local driving behaviors, such as aggressive maneuvers. The primary objective was to develop and validate a calibrated microsimulation model using PTV VISSIM that accurately replicates field-measured delays, thereby providing a reliable tool for traffic engineers and policymakers. The methodology involved a comparative analysis of field measurements and simulation outputs at eight signalized intersections along the Barzani Namr Ring Road. Data collection included video recordings during morning and evening peak hours to determine traffic volumes, queue lengths, and signal timing parameters (cycle length, green, yellow, and all-red times). Geometric data were sourced from official design specifications. The VISSIM model was constructed by replicating the physical geometry and traffic signal plans of each intersection. Crucially, the model underwent rigorous calibration to adjust default German-based driving behavior parameters (e.g., car-following, lane-changing, and acceleration/deceleration patterns) to reflect the specific traffic dynamics of Erbil. Validation was performed using statistical metrics, including the Average Absolute Error (AAE), Root Mean Square Error (RMSE), Mean Absolute Error (MAE), and GEH statistics, ensuring the model’s fidelity against observed conditions. The results demonstrated a high degree of accuracy in the calibrated simulation model. Statistical comparison revealed a strong correlation coefficient ($R = 0.938$) and a coefficient of determination ($R^2 = 0.879$), indicating that nearly 88% of the variation in simulated delay was explained by observed field conditions. Error metrics further supported the model's reliability, with an RMSE of 7.31 seconds per vehicle and an MAE of 5.92 seconds. Additionally, GEH statistics remained consistently below the accepted threshold of 2, confirming that the simulated traffic flows closely matched the observed volumes. These findings validate the effectiveness of the manual calibration process in adapting the software to local driving behaviors. The significance of this study lies in its provision of a localized, data-driven foundation for improving urban mobility in Erbil. By demonstrating that VISSIM can accurately model local traffic conditions when properly calibrated, the research supports the use of microsimulation for traffic planning and intersection optimization. The authors recommend adopting adaptive signal control systems and integrating intelligent transportation technologies to enhance intersection performance. Future research is suggested to expand the model to multiple intersections, incorporate real-time data, and assess environmental impacts, thereby extending the utility of simulation-based planning for broader urban traffic management.

Provenance

The full processing record for this entry. Every stage of this paper's journey through the pipeline is logged — what ran, with which tool and model, how many attempts it took, and when it last completed.

Summary generated by qwen3.6-27b-prismaquant on 2026-06-26; verification: verified.

Topics

Ranked by relevance to this paper. Hover a topic for its definition.

• simulator validity fidelity