After passengers pass the gates, they walk through a
stair to a platform.
• Passengers from the platform pass to the gate with
uniform delay 2.0-3.0 seconds and then exit each gate
at equally probability.
• Assumptions:
1. A slope is 30% and only a plain slope without a stair
case is simulated.
2. The simulation is able to run in 3D.
3. All dimensions and figures can be adjusted with
suitable scales.
4. Other parameters use default.