The A13 is almost empty between those times but is lit up like a Christmas tree, it would be better (and save even more) if they were switched off with a 50 mph limit for safety reasons. When I venture into Kent I notice that even the motorways are not lit at all.
It depends on where the lights illuminate. One of my neighbours had a light on all night illuminating a passage at the side of her house. The problem was due to garages, sheds and high fences and gates anyone standing beneath the light would not be visible from any direction.
I live in an end terrace house and I asked a crime prevention officer about the risk of burglary, he told me that they tend to go for the second house in a terrace as there is less chance of them being seen.