Figure 2.
The 2 line graphs plot values against time in minutes. Panel a shows Q 1 t remaining at 0 until t s 25 minutes, increasing to 1 at t p 35 minutes, remaining at 1 until t dep 40 minutes, then decreasing to 0 by about 43 minutes. Panel b shows 3 overlapping train intensity windows. Train r 1, G 1, departure 35, increases from 0 near 20 minutes to 1 near 30 minutes, remains at 1 until about 35 minutes, then decreases to 0 near 38 minutes. Train r 2, G 3, departure 41, increases from 0 near 27 minutes to 1 near 36 minutes, remains at 1 until about 41 minutes, then decreases to 0 near 44 minutes. Train r 3, G 5, departure 47, increases from 0 near 33 minutes to 1 near 42 minutes, remains at 1 until about 47 minutes, then decreases to 0 near 50 minutes.Illustration of boarding-gate congestion windows: (a) congestion evolution for a single train and (b) overlapping congestion windows for multiple trains served by the same gate