The same thing happened to me and my sister when I was driving from Vegas to Mammoth Lakes after having picked her up from the airport. Only the semi did that right in front of us, and were on the edge of the roadway as it illegally passed another semi so that there were three of us abreast on a two-lane highway in the middle of a blizzard! It was absolutely terrifying and my sister screamed the whole time! After the ordeal, she complimented me on my driving, and has done so ever since! Ha ha.