Sorry for the wording, but not sure how else to ask this, and I have NO idea where to look for something this specific. Would anyone know whether supply lines drove completely during the day, or whether they had drove at night? I bring this up because of a horror story I'm writing that has a section with a convoy getting ambushed by... a thing in the middle of the night. But I wondered, would they be driving at that time? Or would they consider it too risky because of Vietcong? If they did drive at night, was it a special circumstance? Curious about this. Please fill me in on this if you can, and if there's an obvious source I'm missing on this, please point me to it.