You must never drive
faster than is safe for the current conditions. Whether
the road surface is rough, wet, steep, narrow, wide or dry.
If the speed limit is 50 mph, but you are driving in icy
conditions and it's unsafe at 30 mph don't go over 30 mph.
You can be cited for driving "too fast for the conditions",
not to mention possibly killing someone. So keep aware,
evaluate the conditions and make adjustments.