The effect of roadside on speed perception

The study examines how various roadside elements, such as flat areas, trees, slopes, and buildings, influence speed perception. Data from multiple previous studies were combined and reanalyzed using newly established criteria to assess the proximity and nature of roadside features. The dataset includes 9 776 speed estimates, gathered from a wide range of road types and surroundings, allowing for an analysis of how these elements affect speed estimation accuracy.The findings suggest that flat areas consistently lead to overestimations of speed, likely due to the lack of physical cues that provide visual references. In contrast, trees and forested environments have a stabilizing effect, helping individuals to estimate speed more accurately. Built environments, such as industrial zones and urban areas, tend to lead to significant overestimations of speed. These results highlight the importance of roadside environments in influencing speed perception, with natural settings like forests providing clearer visual cues that help drivers and observers better estimate speed.