Yea, I hate road construction. There is about a ten mile section at the end of the video where the eastbound and westbound lanes are actually bridges that hug the canyon walls over the Colorado river. On this day, the eastbound lanes were closed for construction and traffic was diverted to the westbound lanes. If you look, when the traffic gets down to one lane, you can see the eastbound bridge down to the right, just above the river.
It's a cool section of road...if you're into that sort of thing.