Yesterday I saw an incident in the street in front of my house. Our street (a residential collector) has curb parallel parking, a bike lane, and one travel lane in each direction. A cyclist was in the bike lane, and was overtaken by a motorist. Shortly after overtaking the cyclist, the motorist set her right turn signal and slowed to a stop, still in the travel lane, maybe 50 feet ahead of the cyclist. The cyclist maintained his pace (still in the bike lane), passed the motorist on the motorist's right, and continued along the bike lane. When the cyclist had passed, the motorist turned right, across the bike lane, into a driveway.

What made the cyclist so confident the motorist was stopped because of courtesy toward him? Maybe there was a cat in the driveway, so the motorist didn't want to turn in until the cat had moved. After the cat moved, the motorist could have turned right, unaware of the cyclist's presence. Or any number of other scenarios...

In a similar situation I would not have overtaken on the right. I would have moved my line of travel to the left, sufficiently far to pass around the motorist's left side. Under no circumstances would I place myself to the right of a vehicle with its right turn signal on, nor on the left side in the case of a left turn signal.