Originally Posted by
daredevil
You and two vehicles - one coming from the front, one from behind and you all arrive at the same time, 3 abreast. Especially if the two vehicles are large such as trucks and shoulder space is limited or non existent. That's a risky situation unless you ride right of the fog line all the time.
You make an excellent point...especially about a properly adjusted mirror being like having eyes in the back of your head.
Some of my riding involves similar rural mountain roads, with no shoulders, and moderately high speeds (40-55 mph). With the helmet-mounted Take a Look, I monitor what's going on behind me every few seconds, without wavering a cm, and without losing my forward vision.
If I see an overtaking vehicle that might cause a 3 abreast scenario (especially if it's a wide pick-up, or is towing a trailer), I move to the center of the roadway. I also sit up, and indicate with a rearward facing palm that the driver is not to pass. All the time I'm doing this, I'm keeping an eye on the driver in the mirror. When the car(s) up clear I move over to the right, and signal for them to come around.
99+% of the time this works flawlessly, and allows me to control the situation. With the mirror, I can keep my eye on the overtaking driver while I'm taking the lane...something critical to being able to ride this assertively.
And in the rare circumstance where the driver looks intent on passing anyway, I have lots of room to my right to do so...with the mirror allowing for continuous monitoring of the driver, and his position on the road.
I've found that most drivers respect my assertiveness, realizing it's for both our good. Many elderly drivers wave thanks to me (with all 5 fingers

), for taking the ambiguity out of the situation.
For those who were wondering, "Why Mirrors?", I hope this illustrates how they can be better than riding without.