In QLD we are limited to a speed of 30 Kph when filtering, and I believe this helps. But you need to be aware of where you can and can't filter safely . We can also use bicycle lanes at traffic lights as long as we stay 1 metre away from bicycles, which you can do most of the time. Japanese and Italian crotch rockets tend to blast through when highway traffic is stalled, but what they don't realise is that this is a trial, and if they don't follow the guide lines lane filtering could be banned.
Regards Martin.