Then I'm REALLY surprised you're still alive!
Do you slow down for fog, heavy rain, snow, possible ice, etc?
It sounds like YOU are the horrible driver here. Aside from reducing one's speed in the conditions above there is no reason to significantly lower your speed below the limit. Doing so would cause far more accidents then would be avoided. You have to be afraid of nearly everything on the road to slow your vehicle down merely because its dark out perhaps driving isn't for you. As for me when it rains, snows, and fogs I prefer to increase my speed so I get through it quicker thus I am out of the danger sooner.