Some interesting differences in opinion here.
We've got the "never ever" crowd
The "far to the left as possible and get off and walk" crowd
The "be really careful" crowd
and the "you're all gonna dieeee!" bunch.
Sadly yes, cyclists are killed on major roads far too often, but that doesn't mean we should be forced off major roads, or made to feel we can't use them.
Maybe something akin to Reclaim the Night marches, Reclaim the A roads. Critical Mass rides tend to be more about raising awareness on city streets, but there are many major roadways that would be safer if there was occasionally a large cyclist presence, and more thought given to raising driver awareness of cyclists.
*beings planning*
Any road can be dangerous if drivers and cyclists aren't paying enough attention, cycling defensively is a good step to take on any road.