The start time of breakdown versus inflows classified by desired speed. (a) Box-plot for the reference scenario, (b) box-plot for pedestrians with medium heterogeneity in desired speed, (c) box-plot for pedestrians with large heterogeneity in desired speed, (d) box-plot for pedestrians with homogeneous low desired speed, (e) box-plot for pedestrians with homogeneous high desired speed, (f) box-plot for pedestrians with two different desired speeds.