Lane splitting is legal in California.

But honestly, how does this reduce congestion? My experience is that these motorcycles often dart between cars causing drivers to swerve slightly and tap their brakes.

I would argue this makes congestion worse as it causes more cautious drivers to brake (sometimes abruptly) and almost always slow down.

Finally, it is important to consider that as a vehicle, most of us are not looking for you and make small changes from left to right while in our lanes. It is not a goal of mine to accommodate motorcycle riders while driving. Splitter beware.

I'm all for sharing the road-- be we all need to subject to the same rules.