San Diego to las Vegas Nevada

Stay on the I-15. There is some construction work on the I-215 between the 60 Fwy and the I-10.

Either is fine. Check Google Maps for traffic on a similar day to know what to expect.
Check traffic again just before you roll. Often an accident on one route will have you drive plan B.

X2 on I15. We live in San Diego area and use this route a lot. BTW "white knuckle" are the constant in SoCal.

You don't have many choices.
Years ago, being in Palm Springs I took short cut to Las Vegas.
I drove SUV and shortcut saved us 60 miles, but than 60 miles driven on sand roads at the time when GPS were not available sure gave us some adrenaline boost.
Good part, on sand road I was driving faster than average I-15 speed.

X3 I-15

You'll run into slow spots in several areas, however once you reach the top of Cajon Pass and drop down into Hesperia/Victorville it will be smoother sailing.

Tara361 wrote:
Having never driven in Calif., I am trying to determine Which is the best route going north (congestion, etc.)

A Straight up I15 all the way

B I15 to I215 to I15

Not necessarily looking for the fastest or shortest, looking for the least amount of white knuckles ha ha

Thanks Bob

Tara,
Well, that route sucks, any time. The main reason is, it's the primary artery between the two towns. It's used by a few zillion trucks, on an every minute basis. We lived in San Diego for 50 years and, drove that route many, many times, and due to the fact that, it was the primary route to points north, Utah, Colorado, Yellowstone, Glacier, and a whole lot more, above that town of Vegas.

But, we had to do 'cause it was basically the straightest one. Well, because of that, EVERYONE ELSE USES IT TOO! Now, depending on what you're intending on seeing and doing in Vegas, what your schedule is, and general plans, and of course, your thoughts for driving at night, doing that run from San Diego to Vegas in the middle of the night is SERIOSLY EASIER and a infinitely less traffic than in the middle of the day.

I know, I've done it way more than once. Not nearly as many trucks and, general travelers. Besides, in all reality, there is absolutely NOTHING to see, between the two towns, besides desert. So, you're not missing any SIGHTS, if driven at night. Some folks have a hard time driving at night due to eye problems, judgement issues and more. I enjoy it, especially if I know I'm not missing anything. Everyone's travel mode is different. Your choice.
Scott

Stay out of either route during prime rush. Avoid Friday at all cost unless you get thru early in the day. I would go straight up the 15 fwy both routes are under construction. You may hit slow traffic between the 91 and the 210 on the 15

Like rkentzel mentioned, if you are taking 15 it can be a parking lot all the way to Vegas on Friday starting around noon, and a parking lot all the way back on Sunday starting around noon. And I thought it would be better in the summer since I didn't think that many people would head from LA to Vegas when it was 115 in Vegas... I was wrong. They still go there. And don't go anywhere near 15 on a three day weekend.

rkentzel wrote:
Stay out of either route during prime rush. Avoid Friday at all cost unless you get thru early in the day. I would go straight up the 15 fwy both routes are under construction. You may hit slow traffic between the 91 and the 210 on the 15

This is why I suggested that if, you absolutely have to use that route, do it in the middle of the night. Waaaaaaay less traffic.
Scott

BTW Prim Valley and Jane are RV friendly casinos and allow RV overnight.
Better parking in Jane, but more attractions in Prim.