Q&A - Are we legally required to use flashers at a controlled left hand turn intersection?

1. You can't assume that other vehicles, pedestrians, and cyclists are aware of the sign s and road markings facing you - so yes, you should signal even in a committed turn lane.

2. One is never required to signal what you're doing - that's obvious.  But you are required to signal intent.

3. Your wife should chill out.  Wrapping the flasher unit with a piece of dense foam might help ... 

I agree, regardless of whether it is required by law or not, a defensive driver will signal all turns and lane changes.

The law requires:

Signals on turning

170  (1) If traffic may be affected by turning a vehicle, a person must not turn it without giving the appropriate signal under sections 171 and 172.

(2) If a signal of intention to turn right or left is required, a driver must give it continuously for sufficient distance before making the turn to warn traffic.

(3) If there is an opportunity to give a signal, a driver must not stop or suddenly decrease the speed of a vehicle without first giving the appropriate signal under sections 171 and 172.

So, if no one else was around, you would not have to signal the turn. You would have to signal the lane change into the left turn lane though:

Driving on laned roadway

151  A driver who is driving a vehicle on a laned roadway

(c) must not drive it from one lane to another without first signalling his or her intention to do so by hand and arm or approved mechanical device in the manner prescribed by sections 171 and 172,