I think it depends on the roads you are turning off of and on to... if they are narrow roads and people had to wait patiently to get around you, passing when they are stopped is kinda rude, IMHO, especially of the road you are turning onto is also narrow and difficult to pass a bike.

If either of the roads make it difficult for drivers to pass then I would wait in line so people do not get frustrated and try to pass me when it is not safe.