In the UK filtering between lanes is both legal, encouraged, and widely accepted on both motor bikes and bicycles

Legally speaking filtering is fine for both bicycles and motorcycles in the UK. I imagine if someone is the type to get mad at a motorcyclist doing this then they'd probably get mad at a cyclist too.

I will say that there's a massive size disparity between the two, with motorbikes capable of weighing 400kg while the average road bike is closer to 10kg. I know which one I would be more nervous about when I see it weaving by me.

If you were on a motorbike test, you'd fail it if you didn't filter. Much more dangerous to sit in traffic.

So many people inventing laws on this thread.