Cutting thru traffic or "weaving" is illegal. However when traffic is stopped at a traffic light it currently is legal for a motorbike to cut thru to the front, altho they are trying to make it illegal. But once traffic starts moving again they must fall back into line and stop weaving thru the cars. It is highly dangerous, if someone was to open a door at a traffic light to remove their seatbelt/dress caught in the door, or to get a bee out of the car or any reason, someone could be seriously injured or killed. Most motorbikes assume that they can accelerate faster than the average car, so they don't think much of it when they take off from the lights and then drift into the middle of the lane, however they get a massive shock when they realise there is a car right behind them.

Riding a bike is dangerous, and always will be because some bike riders put them selves in stupid situations. Several times i have gone to change lanes fairly certain there is no one around me, then when i look over my shoulder just to be sure, i see a fucken bike sitting in my blind spot. Used to happen heaps on the way home from work. Its fucken annoying.