Around San Diego, we rarely use any freeways but the I-5, and SR-56.
From what I’ve seen on those particular freeways, tailgaters, speeders, and my personal favorites–those who don’t know how to make a turn and finish it in the same lane–especially when entering or exiting a freeway ramp–seem to come in all varieties, so I can’t say I’ve noticed any particular group of offenders.
Trouble is that apart from maybe 163 via Balboa Park, your freeways are EASY to drive on. Which lends itself to idiocy. Imagine driving the following at night … 60 mph speeds, no shoulders, no exit ramp to speak of:
Then again, you have some amazing mountain roads (76, 78, 79 whatever) in east County, and I marvel how well and quickly local drivers run them!