Failure to move for sirens

[Tingle]

"Failure to move for emergency vehicles" was previously a fineable offence but now it is not. What was the reason behind this? Does it fall under any of the other offence categories that remain in place?

I've noticed an increasing tendency for cars not to move for sirens or to at least not properly move for sirens, in that although they might shift to the right of the road, they will maintain their speed. Hence, why I am curious.