As someone that drives through the merge everyday I would say the only day that would take an hour to get Carlsbad would be Thursday, and some Fridays. Once you get to somewhere around Via De La Valle/Lomas Santa Fe it opens up. Back to the 70’s and 80s. Now I do think there is another bottleneck up around Leucadia or La Costa but I don’t that far very often to know if it’s really a big slow down.
I leave from Genesee up 5 to Birmingham and it rarely takes me over 40 minutes and most days it’s 25 or so around 4:00-4:30.