I'm afraid you are getting side track.

恐怕你离题了。

Who would turn to go onto the side track?

有谁选择转向一边岔道的？

It was running by some cars on a side track.

它正驶过旁边轨道上的几节车厢。

How many would turn the trolley car onto the side track?

多少人会把电车开上另一条轨道？

So you can turn the trolley car, if you want to, onto the side track.

所以你可以选择把电车拐向那条分岔路。