We live in Burbank - which is just past Hollywood. This is often the time frame we drive down to the park. Get on the 101 freeway, which will dump you into the 5 freeway.
We have never had it take us more than 1 hour 15 minutes or so during that time - usually it's about 50 minutes. The only thing that will take you longer is if there is an accident.
Traffic is slow, but it's fairly safe to drive. When we use words like "nightmarish", it just scares folks unneedlessly. I feel safer driving in LA than in most parts of the country. (I'm a St. Louis native and travelled for work in a different city every week once upon my career....)
Now, Boston - that traffic scares me!