Cyclist gaze behavior in urban space: An eye-tracking experiment on the bicycle network of Bologna

The increase of cyclist presence in urban areas and of the number of cyclist accidents on roads lead researchers to explore the in-traffic visual behavior and hazard perception of cyclists. In this study the actual cyclist gaze behavior while cycling on bicycle tracks-exclusive or shared with pedestrians is analyzed. The intent is to allow a better comprehension of those elements representing interferences, which can influence user's trip. Field tests were performed in the urban center of Bologna, Italy. 16 participants were asked to wear mobile eye tracking glasses and cycle along a defined route. From gaze data recorded by the mobile eye detector, we analyzed which visual information are detected. By applying fixations detection algorithm and then a frame-by-frame analysis we calculated the proportion of fixations-number and duration-across different areas of interest. Proportion of fixations and fixation time are assumed as a proxy of visual workload. Thus, the relative frequency of fixation has been used to rank those elements that draw cyclist attention. Three are the main outcomes: first, an equilibrium of attention location between the central ( trajectory) and lateral parts of the visual scene can be assumed as the optimal cycling visual condition. This condition results compromised when the presence of pedestrians is high. Second, discontinuities of the path ( like intersections and crosswalks) and the presence of pedestrians are the elements requiring more attention. Third, the absence of physical and visual separation between cyclists and pedestrians seems to lead to a lack of attention to these risk elements. These outcomes about cyclists' visual behavior allowed to recommend design measures to increase comfort and safety on shared-with pedestrian-cycling paths. Thus, suggestions are addressed in the conclusions. (C) 2016 World Conference on Transport Research Society. Published by Elsevier Ltd. All rights reserved.