Timothy J. Lee wrote:
> Suppose you are in the following situation:
>
> -------------------------
> other>
> - - - - - - - - - - - - -
> you>
> -------------------------
>
> The other vehicle is behind you, not overlapping, going about the
> same speed as you are. You are approaching a place where the road
> splits. The right lane must turn right, and the left lane must
> turn left.
>
> You intend to go left. You turn on your left turn signal. Then
> the other vehicle speeds up to pass, then cuts closely in front of
> you in order to barely make the right turn.
>
> Why the pointless and risky passing in this case when the other
> driver could have just gone in behind you, knowing that you would
> soon be out of his/her way (because you were signaling that you
> were about to go the other way from where s/he wants to go)?

I agree, but in your shoes I would prevent the problem -- by not
signaling. This is a great example of a case where signaling a lane
change can do only harm.