If there's no tire tracks there, or has been there long enough to be iced over, it's no longer part of the roadway anyway. When you take a lane, you demonstrate this.
'Cept as filtersweep says - you can't see what your brain doesn't comprehend as a possible reality, say, a person riding a bicycle in winter temperatures or conditions. if that's the case, you have to take a lane too, if those types will never see you anyway.