OK, this is have a General Question, and half a bitch about road construction. Why is the hell do they have to close off 8 miles of road to work on 100 yards of it?
Of course I meant half and not have up there.
Well, you’re exagerating, of course. They didn’t seal fof 8 miles just to work on 100 yards. More likely, they sealed off 8 miles to work on 50 yards.
I find your lack of faith in the American Union system disturbing.
Jeez, how did the union get blamed for this?
We need someone who has managed a road project, but I’m guessing that there are efficiencies in “clearing the work table”.
I agree though, it’s maddening to drive mile after mile in a single lane when there is no work being done.
Ok here’s my first official WAG:
Let’s say the job is to replace all the Botts Dots* along a seven-mile stretch of highway. You close off all seven miles at once, plus an eighth mile at the start to squeeze all the traffic gradually into one lane. Each mile of road takes an hour to work on (with an hour off for lunch), plus whatever time it takes to put down the cones and pick them up once you’re done.
That last part is the kicker. It’s much much easier (and safer) to close off the entire worksite at once, rather than move the cones every hour. Not that it matters if you live in a place like L.A., where all the highway work is done at night. 
- Botts Dots: Those noisy reflective bumps that mark the lanes on a highway, named after Caltrans engineer Elbert Botts