unescorted

The President's unescorted vehicle was ambushed just outside the capital.

刚出首都，总统无人护卫的汽车就遭到了伏击。

Such a visitor wouldn't have been allowed into the plant unescorted.

这样的来访者就不会无人陪同而被允许进入厂内.

Unescorted children are not allowed beyond this point.

小孩无人陪同不允许走出这个地方。