It's coldest at night, so morning ice would be worse than evening, when daily highs are reaches and roads have been driven on more.

Generally the coldest part of the day is just after sunrise. The warmest part of the day is typically in the early afternoon, around 1-4 pm.

This makes a few driving hazards more likely or more intense in mornings, including fog, sleet, and ice. Also tires have less traction when they are colder. In the morning it is less likely for snowplows or earlier traffic to have cleared paths on secondary roads.

Driver assist systems tend to have more trouble with sensor fogging, frosting, or icing in the morning.

That's not to say evening is a piece of cake. Evening tends to have denser traffic which increases the risk of accidents. Places that are in shadow for much of the day might maintain ice while most of the morning ice melts, or might start developing new evening ice earlier than places the heated up more in the day which could be particularly bad--if most of the road is ice free in the evening people might let down their guard.