I can't speak for all fwy's but I can sure speak for a few. Here is my opinion of traffic on select fwys in the LA Basin (note this excludes car pool lanes which make life quite a bit easier)

Mornings:

Harbor Freeway (110) North from the 405/110 interchange to the 5/110 Interchange just north of DTown. Southbound is fine in the morning from the 10/110 interchange. however the Pasadena Fwy (110 still) southbound from Pasadena to the 10 Fwy, it is slow in the morning and Northbound in the a.m. from DT to Pas is open in the morning.

105 Freeway: Westbound to LAX is slow in the morning. Eastbound is clear at least to the Harbor Fwy.

SD Fwy (405): always sucks, and that is the truth.

Hollywood Fwy (101) always sucks near DT; from the Valley to the 405 its Southbound traffic in the a.m.

Afternoon/Evening:

Harbor Fwy, opposite of the morning
Note: DT is always congested especially near the Hollywood Fwy (101)

Hollywood Fwy at night sucks northbound to the valley

Pasadena Fwy: opposite of the morning

105 : Eastbound is slow from LAX to at least the harbor fwy

SD fwy, see morning as it never changes

Another major artery although not a fwy is Sepulveda Blvd which sort of runs along the 405 and is bad Southbound in the evening and Northbound in the a.m. especially in the South Bay.

Now that this sounds bad, the one incredible thing about LA is that if one fwy sucks there is always another one you can use and no stinking tolls.