There is data available in regards to when the worst time of day is to hit the roads out on the west coast. Larger cities like Los Angeles have been the primary subjects of this research, but the results can largely be assumed to match up just about anywhere a person travels on the west coast.
A lot of people were curious about when the worst times were to be on the roads in Los Angeles recently due to the Thanksgiving holiday and all of the traffic associated with that. Fortunately, thanks to reporting by NBC Los Angeles, we have the answer to that question.
It turns out that the worst time to be on the roads in Los Angeles this past Thanksgiving was between the times of 3:15pm and 6:00pm. This was when the traffic was the heaviest in the city. This probably had a lot to do with when people tend to eat their Thanksgiving meal, and when they want to get out on the road and try to catch some of those infamous Black Friday deals that many retail stores now offer on Thanksgiving day itself.
If traveling in the west during any particular holiday, it is best to try to steer clear of the roads during those times. If it is possible for you to do your driving during the middle of the night, that would probably be the best possible solution. Baring that, try to avoid those mid-afternoon hours as much as you can.