The 78 should serve as the “go no further” point. I live in S. Carlsbad but my baby goes to day care in N Oceanside/Vista.
I hate everything about having to cross the 78. It is a traffic nightmare because of that damn stoplight to merge onto I-5 south. Another thing I have noticed about Oceanside, the infrastructure was clearly an afterthought when they planned the city. Power lines crossing over major thoroughfares, the lanes aren’t lined up properly, and crossing train tracks.