Understanding visual behaviour within the urban environment to optimise lighting

A review of the literature suggests that current guidelines for road lighting lack a clear empirical basis. Where there is evidence, this tends to be based on motorists or pedestrians: there is little, if any, consideration given to the needs of cyclists. This thesis presents an investigation of lighting for cycling after dark within an urban environment. Three empirical investigations were conducted. A field survey was conducted to investigate the influence of the ambient light level on the tendency to cycle. Mobile eye-tracking was used to investigate the gaze behaviour of cyclists in natural settings, using two parallel measurements to reveal the critical of these fixations: performance on an audio dual-task and skin conductance response (SCR), and by that improved the ecological validity of previous similar research. A laboratory experiment was conducted to investigate obstacle detection under variations in the type, location, and level of lighting. The field study revealed that cycling increases when the ambient light level is higher. This suggests that road lighting might be a tool to encourage more cycling. The eye-tracking study suggested that observing the path ahead is a critical task, reflecting a tendency to search for possible obstacles on the road. Post hoc analysis of the eye-tracking data also suggested an influence of ambient light level on gaze towards aesthetic elements (architectural features) of the environment with such elements are suggested by the literature to be associated with positive cycling experience: this suggests that appropriate road lighting motivates the choice to cycle. The detection experiment revealed two significant effects: first; that road lighting and bicycle lighting may conflict. In other words, using bicycle lighting on a lit road may impair detection performance, not improve it. Second; that detection is improved when the front bicycle lamp is located on the wheel hub rather than the handlebar.