Again, sticking to the ACA routes will generally keep cyclists off the highways, even the ones with wide shoulders. There are spots with nil shoulders that simply cannot be avoided e.g. 101 south of Crescent City. My experience has been that motorists, whether they like it or not, will be as accommodating as possible. While it may seem daunting, it just is not that bad. Cyclists that are visible and that ride sensibly will have little trouble. It sure beats staying at home. If you're going to worry about this, then no amount of words here are going to assuage you. Like I said earlier, there are hundreds of cyclists that ride this route every year in sun and rain. There's very little to worry about.