they're doing a huge amount of construction at 405/22 interchange so when I saw the sign in Irvine that freeway was closed 10-15 miles north I took 55 to 5 back to LA.
as for the dui checkpoint, that's a brilliant revenue scheme/stream for whatever town nabs the drunk drivers (or CHP) but a slow PITA for anyone thinking they'd easily detour around freeway closure. glad I took alternate route that night...and stopped drinking earlier this year (for now, hopefully longer)