Complex sentence: Since 2006, it has followed either all or portions of Highways 4,3,2,216,16, and 43; the alignment has shifted slightly over the years as the component highways have been upgraded, reconstructed, and renumbered.
Split into simpler sentences: Since 2006, it has followed either all or portions of Highways 4,3,2,216,16, and 43. The alignment has shifted slightly over the years as the component highways have been upgraded, reconstructed, and renumbered.