Oh, THAT bites! I've taken that route a BUNCH of times myself. It was also a heavy trucking route to supply Phoenix with all of the stuff that came in from overseas, as the LA basin is a much bigger port area than San Diego is.
It's been teasing around 100 here in Dallas for a couple of weeks, but all things considered it's still fucking hotter in Phoenix. To those of you that say "yeah, but it's a DRY heat": please, TRY it yourself sometime in July when it's 115 to 128 in Phoenix. They broke a record around 20 years ago for the maximum number of days in a row where the LOW temperature at night never fell below 100F. That's not the kind of record you want to break. My air conditioner NEVER FUCKING STOPPED during those 10 (?) days. I had an electric attic fan to exhaust heat out of the attic when the air temp in the attic was over 140F, and it didn't shut off until about 3 or 4 AM during that period.
Luckily Phoenix hasn't had one of those killer July record-breakers for a while.