So. Calif: I-15 at Cajon Pass and also at Las Vegas

Haven't checked but isn't the Oasis on Boulder hwy almost down where CW is? If so I would take Boulder north past AZ Charlies then jump on the freeway north. I always try to stay in the right lane until I get on I-15 then watch the traffic. If it slows jump into left lanes out of Vegas. Once past the big race track at exit 54 things thin out a bit. By staying on Boulder you will miss a lot of freeway tfc through Vegas.