What is the safest and most courteous way to ride on a two-lane road? There is a one-mile two-lane road close to my home with no bike lane, but with a large sidewalk. I ride this road every day, and it got me curious what I should be doing. The speed limit is 35 and the roads are pretty empty except during rush hour.

Most riders either stay close to the curb like below.



And I have noticed that cars pass them on the left, and it seems very unsafe to me when there is another lane.

Other riders use the sidewalk like the below. But since there is a lot of foot traffic and trees and such you would be very slow.



And I do the below.



I hog the whole lane so no cars pass me on the left. I average around 16-18&nbsp;mph on this road, and it's only a mile long. Most of the time it's fine, but during traffic I feel like am not courteous.

And once in a while there are cars parked although very rare like the below. Which I really like because the whole lane is for me, and I can go around the cars.
I use the method in your 3rd picture - I take the middle of the lane when there are no bike lanes. I am helped in these cases by the fact that these roads in my city usually specify the right-most lane as a shared car and bike lane.

Besides the speed issue you state when riding on the sidewalk, it is also hazardous for both the cyclist and pedestrians.

I feel that riding far to the right, while still in the lane, just invites cars to pass you even when there isn't enough room. 

Taking the middle of the lane is my way of encouraging them to overtake the proper way by fully moving into the left lane.