Was just in Buenos Aires, Argentina. Motorcycles are a major form of transportation there. The bikes are smaller but so are the roads. Splitting lanes is a given for them. They would laugh at our description of splitting lanes and our description of heavy traffic. They commonly split down the sides up the middle and if one of those lanes gets blocked when traffic stops they cut over between the front and rear of vehicles to a more strategic position.
It sounds crazy but it works. Very well actually.
In the Bay Area I often split going on 880. I would say 90% of the vehicles let me through once they realize I'm there. What's common is that once I get through the jam there are vehicles going very slow with a quarter mile of open space in front of them. (No reason for a jam.) When they see/hear me going by it seems to wake them up and they increase their speed. (Distracted) Ten years ago I didn't split in a jam and was rear ended by a guy doing 65 mph.
A dangerous situation can be at intersections. A green light doesn't mean the intersection and crosswalks are safe to proceed. The light turns green and bikes shoot up between cars not moving. Sometimes the cars are not moving because they are letting pedestrians, bicycles, or other vehicles clear the intersection. A couple of years ago in the Bay Area a couple of kids were killed and the father lost a leg when a guy on a Harley sped between stopped cars when the light changed. He happened to be on his third DUI, was sentenced to life and was murdered in prison months later. (Was posted in the News forum)
Impatience can be your enemy when riding but especially when in a traffic jam.
Some people don't like you splitting but they also don't like your clothes, religion, hair style, politics, weight, music, etc., etc. Don't ride in a manner trying to appease everybody because you can't appease everybody and you aren't in your groove.