CA Central Valley

We always take 5, then cut over to Bakersfield on 58. From the Bay Area I have to go down 101 to 152 then over to 5. It's a boring ride but I think it's better than 99, with less truck and agri traffic.

If your ultimate destination is Tehachapi I'd take 99. Otherwise you have to cut across to 99 from 5 down near Bakersfield. As already stated, both 5 and 99 are undergoing some major construction projects. Both are torn up through Stockton and 99 is bad through Modesto. A lot of the construction is being done at night so don't think you'll avoid it by going through at night.

Both 99 and 5 have had a lot of repairs over the last couple of years so I don't think there is much difference between the two as far as condition. You'll find bad sections on both.

I drive them both changing based on construction reports or just wanting a change of scenery...not much of a change. Since the speed limit in California is 55 and I am comfortable with RV and toad at around 55 to 60 travel time is not an issue. Both roads are "California Excellent" which means they suffer from deferred maintenance and need repair. There is significantly more merging traffic on the 99 since you enter more small towns with older onramps. So the 5 is an easier drive with less merging traffic, but the 99 is more direct to Bakersfield.
Happy Trails

Thanks, folks.

Well, maybe I should narrow this down.

I'll be leaving Sebastopol and heading for Tehachapi. Normally, I go down 101 and over the GG Bridge. I'm cheap and I don't want to pay the per axle toll again so I thought I'd go south to Petaluma and east eventually on 12. That gives me the choice of 5 or 99 south.

Any other opinions, routes?

Eric

My son was transferred from Woodland to Bakersfield {which he hates} and he travels back and forth every weekend and he says I 5 is much better and faster
than 99. I much prefer I 5 which we travel back and forth to Yuma from Sac three times during the year

Both roads have areas of heavy construction around Stockton. That said, when I go to Bakersfield, I take I-5 to Stockton, Hwy 4 over to Hwy 99, then 99 to Bakersfield. Easiest is 99 all the way.