“…First, we can sort the passengers into three groups, where the passengers with 2 pieces of luggage are arranged in the A area, the ones with 1 piece of luggage are arranged in the B area, and the ones without luggage are arranged in the C area (see Figure 2). The group behavior has effects on each passenger's motion [22,23], so each area should further be sorted into two subareas, i.e., A1, A2, B1, B2, C1, and C2, where the passengers in A1, B1, and C1 have group behavior and those in A2, B2, and C2 have no group behavior (see Figure 3).…”