Investigating the impact of speed hump heights on vehicle speed reduction

Abstract

This study investigates the impact of the height of speed humps on vehicular speed reduction, focusing on two common heights of 50mm and 75mm. Drones were used to capture the motion of vehicles prior and after passing the speed humps. Those surveys were performed in August 2023 in two straight road sections in Kurunagala, Sri Lanka. Tracking software was used to extract the speed trajectories from which speed of each vehicle at 5-meter intervals up to 70 meters before and after the speed hump were obtained. The study encompassed five vehicle categories. Analysis revealed a consistent reduction in vehicle speeds across all vehicle categories in response to height of speed humps. Two-sample t-test conducted for each vehicle category indicate statistically significant differences in speed reduction between the 50mm and 75mm hump heights, with p-values ranging from 0.023 to 0.037 well below the standard significance level of 0.05 for Three-wheelers, Cars, Small vehicles, and Heavy vehicles, respectively. However, Motorbikes exhibited a p-value of 0.286, indicating there is no statistically significant difference in speed reduction based on hump height. These findings provide a valuable foundation for evidence-based decision-making in urban road infrastructure development and maintenance, ultimately fostering safer and more comfortable transportation systems.