I was in L.A. a few weeks ago and ALL riders ride between lanes (on the line) on the freeways. Even the Harley cops do it.
We'd be at a total stand-still in a traffic jam in our rental cage and all kinds of bikes would jet by us at about 50 klicks.
Weird to see... saw lots of very close calls too. Is it lawful? Either way, it's insanity in my mind.