You asked why the drivers pass you in the same lane when there is a generous berth in the other lane. My question for you is where do you ride in the lane? If you ride really close to the edge of the road the driver might assume he can squeeze by. For me, I ride about 1/2 - 1 foot to the LEFT of the fog line. This benefits me by forcing the driver to go around me to pass, as well as if i have a troublesome river i can scramble out of the way to let him get by me. Also if you ride where I ride you avoid road debris that can puncture your tires. That is my two cents.