Been lane splitting in California for 40+ years with no problems. I try to do it under 40 mph though because above 30-40 mph gaps open in the traffic and cagers will start darting in and out without checking their mirrors. I also try not to go more than 10-15 mph faster than the cages when doing it so they have more time to see me coming up behind them. When people move over for me I give them the two finger wave. Most are nice, but even I get startled when I'm in my cage and some zipperhead goes by 40 mph faster than everyone else.