You’re just about to board the plane when you hear an announcement at your gate: All carry-on bags now need to be checked. This can be a huge relief (less weight to lug around!), but it can also be a hassle when you’re waiting around at baggage claim and wondering whether your luggage is lost somewhere far away.

当你正准备登机时，或许会在门口听到这样的通知：所有随身行李现在都需要托运。这既意味着减轻了巨大的负担 (随身携带的东西少了)，同时也会带来巨大的麻烦：当你在行李提取处苦苦等待时，可能会怀疑自己的行李早就被弄丢了。

The reason airlines sometimes make you check your bags at the last minute might not be what you’re expecting, though. According to Vox, it has less to do with the amount of available space in the overhead bins and more to do with the time that’s being wasted by waiting for fliers to secure their carry-on bags. Aviation economics expert Samuel Engel told Vox that airlines lose money for every minute that the plane isn’t flying. He said carry-on bags are the biggest holdup when it comes to boarding delays, so there's a lot of incentive to speed up the process. “You have this $35 million asset you want to make sure you’re flying 10 or 11 hours of the day,” he said.

事实上，航空公司有时会让你在最后一刻托运行李的原因，可能并非如你所想。根据Vox网站的说法，这与你座位头顶储藏箱内的可用容量关系不大，更多则与乘客们确保随身行李安全时所浪费的时间有关。航空经济学专家Samuel Engel透漏道，航空公司在飞机未起飞的每一分钟都在赔钱。他还表示随身行李是导致登机延误的最大麻烦，因此才会有很多措施来加快这一过程。他对此解释道：「要是你有这架3500万美元的资产，也会想确保每天飞行10或11个小时」。

A gate agent at Dallas Fort Worth's airport also told Vox that the staff has just 20 minutes to shepherd passengers onto the plane, and if they take any longer than that, they’re held responsible and could lose their jobs.

此外，一名在达拉斯沃思堡机场工作长达30年的检票员也透漏道，工作人员只有20分钟将乘客们带上飞机，如果他们花费了更长的时间，就将为此承担责任，甚至还有可能失去工作。

Sometimes, though, the mandatory baggage check is related to space. Gate agents often keep track of the number of passengers who board with carry-on bags that are too large to fit underneath their seats. Planes don’t have enough overhead bin space to allow every passenger to bring a carry-on bag, so there has to be a cut-off at some point.

但有时候，强制行李托运确实也与空间有关。检票员会与空乘人员进行飞行前会议，他们需要为登机过程提前制定计划，特别是在航班满员的情况下。与此同时，一些经验丰富的检票员通常也会记录下手提行李太大而无法放在座位下面的乘客数量。由于所有飞机都没有足够的顶部空间来让每位乘客都存放随身行李，因此才必须在某个时刻进行拦截。

To make sure you'll have everything you'll need while traveling, try to pack essential items (like medications and your toothbrush) in your personal item bag instead of a carry-on. You wouldn’t want to lose your carry-on and not have a single pair of clean underwear to change into.

所以说，为了确保你会拥有旅行时所需的一切，请将必需品(如药物和牙刷)装入个人物品袋中，而不是随身行李内。你可不会想在丢失随身行李后没有一套干净的内衣可换。