This is South Florida-centric, but I’ll bet this applies to a lot of other places.
The Palmetto Expressway in South Florida (SR 826) has been in various phases of construction since… well, since I lived here in the 1970’s. A major reconstruction of the interchange with the Dolphin Expressway (SR 836) has been underway since 2009 and is scheduled to be finished early 2016. Then they’ll tear up another portion of it.
LOL