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

Abstract 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.

[1]  J. Henderson,et al.  The Role of Fixation Position in Detecting Scene Changes Across Saccades , 1999 .

[2]  Chandra R. Bhat,et al.  Commuter Bicyclist Route Choice: Analysis Using a Stated Preference Survey , 2003 .

[3]  Michelle L. Reyes,et al.  Effects of cognitive load presence and duration on driver eye movements and event detection performance , 2008 .

[4]  Ying Wang,et al.  The sensitivity of different methodologies for characterizing drivers’ gaze concentration under increased cognitive demand , 2014, Transportation Research Part F: Traffic Psychology and Behaviour.

[5]  M Levasseur Cycling aspects of Austroads guides , 2014 .

[6]  Peter Veelaert,et al.  Cycling around a Curve: The Effect of Cycling Speed on Steering and Gaze Behavior , 2014, PloS one.

[7]  Johan Engström,et al.  Sensitivity of eye-movement measures to in-vehicle task difficulty , 2005 .

[8]  L Aultman-Hall,et al.  Ottawa-Carleton commuter cyclist on- and off-road incident rates. , 1998, Accident; analysis and prevention.

[9]  Chandra R. Bhat,et al.  An analysis of bicycle route choice preferences in Texas, US , 2009 .

[10]  Marc-Antoine Nüssli Dual Eye-Tracking Methods for the Study of Remote Collaborative Problem Solving , 2011 .

[11]  Fred Wegman,et al.  A conceptual framework for road safety and mobility applied to cycling safety. , 2014, Accident; analysis and prevention.

[12]  Michael F. Land,et al.  Predictable eye-head coordination during driving , 1992, Nature.

[13]  Raphael Grzebieta,et al.  Relative injury severity among vulnerable non-motorised road users: comparative analysis of injury arising from bicycle-motor vehicle and bicycle-pedestrian collisions. , 2010, Accident; analysis and prevention.

[14]  Jean Underwood,et al.  Visual attention while driving: sequences of eye fixations made by experienced and novice drivers , 2003, Ergonomics.

[15]  Venkat R. Vattikuti,et al.  Real-Time Human Perceptions: Toward a Bicycle Level of Service , 1997 .

[16]  Karen E. Adolph,et al.  Visually guided navigation: Head-mounted eye-tracking of natural locomotion in children and adults , 2010, Vision Research.

[17]  M. Land Vision, eye movements, and natural behavior , 2009, Visual Neuroscience.

[18]  F A Miles,et al.  Initiation of saccades during fixation or pursuit: evidence in humans for a single mechanism. , 1996, Journal of neurophysiology.

[19]  D A M Twisk,et al.  Studying the role of vision in cycling: critique on restricting research to fixation behaviour. , 2013, Accident; analysis and prevention.

[20]  Gudmundur F. Ulfarsson,et al.  Bicyclist injury severities in bicycle-motor vehicle accidents. , 2007, Accident; analysis and prevention.

[21]  Greet Cardon,et al.  Visual guidance during bicycle steering through narrow lanes: a study in children. , 2015, Accident; analysis and prevention.

[22]  Greet Cardon,et al.  The visual control of bicycle steering: The effects of speed and path width. , 2013, Accident; analysis and prevention.

[23]  Rajesh P. N. Rao,et al.  PSYCHOLOGICAL SCIENCE Research Article EYE MOVEMENTS REVEAL THE SPATIOTEMPORAL DYNAMICS OE VISUAL SEARCH , 2022 .

[24]  M. A. Recarte,et al.  Mental workload while driving: effects on visual search, discrimination, and decision making. , 2003, Journal of experimental psychology. Applied.

[25]  Chandra R. Bhat,et al.  An Analysis of Commuter Bicyclist Route Choice Using a Stated Preference Survey , 2003 .

[26]  Laurie Bayet,et al.  Subjective report of eye fixations during serial search , 2015, Consciousness and Cognition.

[27]  Kristian Trøjelsgaard,et al.  Beta Diversity of Plant-Pollinator Networks and the Spatial Turnover of Pairwise Interactions , 2014, PloS one.

[28]  Hein Botma,et al.  METHOD TO DETERMINE LEVEL OF SERVICE FOR BICYCLE PATHS AND PEDESTRIAN-BICYCLE PATHS , 1995 .

[29]  Kay W. Axhausen,et al.  Route choice of cyclists in Zurich , 2010 .

[30]  Joseph H. Goldberg,et al.  Identifying fixations and saccades in eye-tracking protocols , 2000, ETRA.

[31]  Johan Engström,et al.  Effects of visual and cognitive load in real and simulated motorway driving , 2005 .

[32]  Michiel Christoph,et al.  Speed choice and mental workload of elderly cyclists on e-bikes in simple and complex traffic situations: a field experiment. , 2015, Accident; analysis and prevention.

[33]  Valeria Vignali,et al.  Looking behavior for vertical road signs , 2014 .

[34]  Peter A Cripton,et al.  Route infrastructure and the risk of injuries to bicyclists: a case-crossover study. , 2012, American journal of public health.

[35]  Greet Cardon,et al.  The implications of low quality bicycle paths on gaze behavior of cyclists: a field test , 2014 .

[36]  Nagui M. Rouphail,et al.  Operational Analysis of Uninterrupted Bicycle Facilities , 1998 .

[37]  R. Fuller,et al.  Iconography : Task difficulty and risk in the determination of driver behaviour , 2007 .

[38]  Federico Rupi,et al.  An Analysis of Bicycle Travel Speed and Disturbances on Off-street and On-street Facilities☆ , 2015 .

[39]  Greet Cardon,et al.  Dealing with head-mounted eye-tracking data: comparison of a frame-by-frame and a fixation-based analysis , 2013, ETSA '13.

[40]  John Parkin,et al.  The effects of cycle lanes, vehicle to kerb distance and vehicle type on cyclists' attention allocation during junction negotiation. , 2014, Accident; analysis and prevention.

[41]  Andrew T Duchowski,et al.  A breadth-first survey of eye-tracking applications , 2002, Behavior research methods, instruments, & computers : a journal of the Psychonomic Society, Inc.

[42]  Moshe Eizenman,et al.  An on-road assessment of cognitive distraction: impacts on drivers' visual behavior and braking performance. , 2007, Accident; analysis and prevention.

[43]  Joan N. Vickers,et al.  How far ahead do we look when required to step on specific locations in the travel path during locomotion? , 2002, Experimental Brain Research.