On a 3-lane 35 mph road, drivers can usually move into the center lane to pass with little delay if the lane is narrow. I am comfortable riding this type road at slow speed with my son on a trailer-bike behind me.

I used to bike commute almost daily on a 3-narrow-lane 45 mph road. I rode on the right side of the travel lane, just a bit to the right of the right tire track. Cars moved into the center lane to pass. I didn't feel the need to "control" my lane because the center lane was almost always available for passing, and drivers didn't seem to hesitate to put their left tires into the center lane. But at locations where the center lane was occupied by traffic or a raised median was installed, I moved into the center of my travel lane.

On 4-lane roads, I always control the rightmost lane if it is narrow. If it is wide, and I'm going a lot slower than other drivers, I ride the right side of the lane.

None of the busy roads on my commute have usable paved shoulders or bike lanes. The only time I ever pull off the road is if there is a 2-lane road with heavy oncoming traffic that has caused a lot of traffic to back up behind me for more than 3/4 of a minute. This happens less than once every few years because I try to avoid long stretches of narrow two-lane roads with heavy traffic so I don't have to deal with this issue.