In some cases the boarding gates are remote from the central terminal (Stansted) or there is a need for interchanging passengers to move from one terminal to another (Heathrow, Frankfurt).

• 有些时候登机门离中央站很远（如斯坦态德机场），或者需要将乘客从一个站点送到另一站点（如希思罗机场，法兰克福机场）。