I use the bicyle lane when there is one. But in the city with cars parked on the road side I simply have to keep 1 meter distance to the side to avoid dooring (google it!) and that puts me into into the middle of the lane. Which in turn means that cars behind me have to use the oncoming lane to overtake me. If I were cycling more to the side the cars behind me a) wouldn't slow down b) overtake me with little to no space around me and thus endanger me in all those unexpected siutations on the road. Also, who said those roads are just for cars? Roads have been around since roman times, unlike cars.