Signaling turns and stops.

“The driver or operator of a vehicle upon a highway before turning to the left or right at any intersection or into a private road or driveway or from one lane for traffic to another lane for traffic or to leave the roadway shall first see that the movement can be made in safety, and if the operation of any other vehicle may be affected by the movement shall give a signal plainly visible to the driver or operator of the other vehicle of the intention to make the movement.” 142. Signaling turns and stops – Highway Traffic Act.

And what do most of us do? We turn our signals on at the same time we make the movement, disobey the HTA and deprive other drivers of any warning. It’s not that hard: signal first, then slow down, then turn.