A dark rainy night can already be a dangerous situation due to the slick road surface and the reduced ability to see at a distance, but it also seems like it makes the roads darker, making them harder to navigate.
When you are driving down a dark road, the light from your headlights scatters off the rough road surface and some of it is reflected back to you. When the surface is wet, it becomes more reflective. More light is reflected away and less light is scattered back to you.
