Ask yourself - is it safe? is it legal? is it worthwhile?
You must have a planned safe place to stop before you go e.g. a gap in between cars.
Don't make yourself the "meat in the sandwich" between two lines of moving vehicles. If they are stopped it's ok, but you have to be careful about when they start moving again.
I always go at the front at traffic lights even if I'm over the white line, so I put safety ahead of the letter of the law.
Give other vehicles a wave if they help you out e.g. move over for you.
It is a grey area and does take a while to get the hang of it.
Be aware that other vehicels are not expecting you to appear.
