Quote Originally Posted by 924Guy View Post
Fair question.

I'll ask this question - how can you expect the defending driver to actually know you're there if he can't see you?

Don't forget the GCR 9.1.3.D.9.d - "Any interior or exterior mirrors may be used."
If he cannot see you, then how is he the "defending driver"?

Seriously, though, read 6.11.1.D in its entirety:

The overtaking driver is responsible for the decision to pass another
car and to accomplish it safely. The overtaken driver is responsible
to be aware that he is being passed and not to impede or block the
overtaking car. A driver who does not use his rear view mirror or
who appears to be blocking another car attempting to pass may be
black flagged and/or penalized, as specified in Section 7.
Note the phrase "responsible to be aware" and the reference to using mirrors. If one's mirrors don't show the road behind, it's time to adjust them.

In general, I would counsel folks against looking for deep or convoluted meanings in the GCR. Here is an extract from section 1.2.3.A (Interpreting and Applying the GCR):

Interpreting the GCR shall not be strained or tortured and applying
the GCR shall be logical, remembering that the GCR cannot specifically
cover all possible situations.
The simple, straightforward reading is the correct reading.