In California, California Vehicle Code § 21209(a)(3) expressly permits a motor vehicle to enter a bicycle lane “to prepare for a turn within a distance of 200 feet from the intersection” -- among other cases. (The vehicle must yield to cyclists in the lane.)
The vehicle code not only permits cars to enter the bike lane prior to a turn, it requires them to do so (https://leginfo.legislature.ca.gov/faces/codes_displaySectio....). My brother failed his first driving test because he didn’t know that he had to enter a bike lane on the left side of Fell St right outside the DMV (back before they separated the bike lane).
I hope that means yield to cyclists ahead of them. To me the whole point of getting in the bike lane is to avoid cases where the cyclist going straight is in a blind spot during the car's right turn. As a cyclist I'll sometimes get into the car lane at intersections to make sure I'm seen. seems like the car being required to let the bike behind them go straight is exactly what you'd want to avoid
Merging into the bike lane before turning right is safer for cyclists. Drivers are supposed to do shoulder checks when changing lanes (I mean they're also supposed to do them when turning but you know) so they likely won't hit a cyclist when merging into the lane.
Once the car is in the bike lane, any bike going straight is forced to remain safely behind the car until the car completes its turn.
In California, California Vehicle Code § 21209(a)(3) expressly permits a motor vehicle to enter a bicycle lane “to prepare for a turn within a distance of 200 feet from the intersection” -- among other cases. (The vehicle must yield to cyclists in the lane.)