Your desire to be near population is admirable - however, it is not always prudent to aim to land on a highway/motorway/autobahn.
How are these road normally lit? - Well - by lights on poles or lights strung across them! What do they tend to have on the side of them.....signposts! What uses them....motor vehicles.
Heard say of a guy who successfully put it down on a highway only to then get run over by an 18-wheeler! Not sure how true that one is.
Go as direct as possible, as high as possible and be speaking to someone at all times. Pick towns or other features that are known to be lit as your turning points - you can't always guarantee a road junction or river or rail crossing will be lit sufficiently at night.
One of the most memorable flights I've had is a night return from Yuma to San Diego, following the border with Mexico. Well lit all the way up to the border on the southern side - hardly a light on the northern side. Wasn't too worried about motors going pop on that one....had two of them!
