Rural roads here are often two lanes and 55 MPH. I try to avoid those if at all possible. Most of the roads closer to towns are still two lane and 40-45 MPH or so. Many of those roads are narrow, and either have no shoulder, or an 18" or so wide shoulder, often with rumble strips to alert drivers that they are about to end up in the ditch alongside the road. Those rumble strips make it impractical to ride to the right of the white line, unless you're training for the cobbles of Paris-Roubaix. And, even where there are no rumble strips, I still wouldn't ride there, because it only encourages close passes.
Add to that the recent explosion of building in the area, and the resulting exponential increase in vehicle traffic. When I first moved here, the roads I rode regularly were between fields of grazing cows or peach orchards, with the occasional farm tractor. Now, those roads are lined with housing developments and 100+ unit apartment buildings, but the roads themselves haven't been 'upgraded' to handle the extra traffic.
I ride with a helmet mirror, Varia radar, a blinking headlight, two blinking tail lights (one on my helmet, one on my seat post) and two GoPro cameras (forward and rear facing.) I seldom ride alone anymore, because I believe a group of riders is more visible than a solo rider, and there is some safety in numbers.
All you can do is to make yourself as visible as possible, stay alert and aware of traffic around you, and try to never allow yourself to get into a position where you don't have an escape route if needed.