The most common type of fatal accident that occurs in the dark is single-car accidents.
About 40% of all single-car accidents happen in darkness or at dawn and about 30% of all fatal accidents are single-car accidents.
Most fatal accidents that happen in darkness or at dawn are likely due to fatigue. That the drivers simply fell asleep, or just nodded off for a second, behind the wheel and drove off the road.
It is important to recognize and listen to your body's signs of fatigue. Never driver if you are too tired!