I really have to give credit to Los Angeles drivers for their courtesy. They aren't required to give you space when you lane split, but they can't block you. Important distinction. I ride everyday. I lane split, at some point, every day. I normally flash my high beam when splitting and they definitely make room. Not all. But some. And I appreciate those that do. I always try to acknowledge them with a wave. The ones who don't move over, i motion that they could move over just an inch, a lot of them do. And many may not see you, but they see the car behind them move over a bit, and they move over a bit too. It might be my bright ass headlight though.