There are lots of places where merges and splits, or (former) toll stations widen the road. But to be considered an n-lane road, it ought to be n lanes for a significant distance, without counting short temporary lanes. I-15 south of Escondido, CA has about 13 miles of 14-lane highway, five regular lanes in each direction, plus four express lanes with a zipper barrier which is usually 2:2 but switch to 3S:1N for most of the morning. That's because it was built through comparatively empty land.