Return trip effect refers to the illusion that the return trip takes less time than the initial trip, even when the distance and actual time of both trips are the same.

“返程效应”指的是一种错觉，总觉得返程用时间比去程的时间短，而其实路程距离和所花的时间都是一样的。

What causes this so-called "return trip effect"? You might guess that it has something to do with knowing the route -- on the way back, you see landmarks that help you better gauge when you’re close to your destination. Well, you'd be wrong! According to a study, the return trip effect is seen even when people take different routes on the outward and return trips.

那么，产生“返程效应”的原因是什么呢？你可能会觉得是因为返程时你已熟知路线，在返回的途中，你看到的一些地标物可以帮助你估计距离目的地还有多远。可是，你错了！有研究显示，出行和返回时采取不同的路线时还是会有“返程效应”。