“Highway speeds” sounds a bit dramatic.

In a snow storm on icy roads it’s safe to assume the speeds would be as slow as safety dictates, just as the speeds should also be for humans in the same conditions.

Also, computerized traction control is amazing, especially with electric drive and no transmission lag. When driven by a human it’s not infallible, but if the car doesn’t have the flawed yet behaviors that humans sometimes have, it could be pretty competent. They’ll have to get it to the point of being able to do without lane lines too of course.