From Vegas heading to Cali:
Take 15 to Victorville  
Turn off at 18
Take 18 to 14 (pearblossom highway)
14 to 5
Bam you are in LA

No need to sit in traffic staring at car dealerships
It's an older highway one lane each way but it's all beautiful desert and farmland driving all the way across the north of the mountains
I use this route to and from LA every time and it SAVES TIME!
even though the speed limit is slower ..there's usually noone else going that way (although this week during i15 closure it will be mayhem)
I get to LA an hour faster than taking the 14/605/10 route.

truck drivers and bikers use this route ...because they know  

I used to own a trucking company so I'm always searching for better routes