Critical pedestrian tasks: Using eye-tracking within a dual task paradigm

Current guidelines for road lighting illuminances on residential streets appear to have little empirical basis. Evidence is needed to determine suitable illuminance levels, and one element of this evidence involves understanding the critical visual tasks o f pedestrians whilst walking after - dark . An eye - tracking study with a concurrent cognitive dual - task has been carried out in order to identify these critical visual tasks . Preliminary work showed that reaction time (RT) to an audio stimulus is impaired by visual distractions. A subsequent experiment was carried out in which participants walked a short route whilst wearing eye - tracking equipment and carrying out a RT task (responding to randomised audio stimuli by pressing a handheld button). The route inclu ded the residential areas adjacent to a university campus and was repeated in daylight and after - dark . It was hypothesised that instances of impaired RT during the route indicated the diversion of attention to some critical task or object in the environmen t. Analyse s of the data involve: i) Using impaired RTs to i dentify moments of distraction; ii) Identify ing objects/areas fixated at these moments of distraction ; iii) Compar ison of critical and non - critical fixations; iv) F ixation duration and frequency for different categories of object/area; and v) mean walking time for discrete sections of the route . These s analys e s will compare the daylight and after - dark conditions to determine any significant differences.