Quantifying the impact of static and dynamic side friction on urban traffic performance in Hilla city

Abstract

This study investigates the impact of side friction (SF) on traffic movements for selected urban roads in Hilla, focusing on how static and dynamic friction elements influence traffic flow and speed. The primary SF elements observed include parked vehicles and pedestrian movements with more dynamic interactions, such as erratic road crossings. Traffic data collection was conducted on four distinct Hilla streets using elevated video cameras that recorded traffic volume, vehicle speed, and SF events. Data recording occurred on Sundays, Mondays, and Wednesdays, both in the morning and in the evening. An analysis of the recorded data revealed significant variations in traffic behavior due to SF elements. On streets with high commercial activity and educational centers, a notable reduction in average vehicle speed was found to be correlated with periods of high SF activity. During the busiest hours, the speed reduction reached 51% in comparison to periods of low SF activity. This substantial impact underscores the sensitivity of urban traffic flow to side friction factors, particularly during peak hours. Dynamic SF events, such as pedestrians crossing roads erratically, had the highest frequency during evening hours, aligning with the end of business and school activities.