Am I the only one who doesn't think steam rolling is a product of bossiness?
Honestly, usually when I steam roll someone it has nothing to do with the person. It is more that they got caught in the line of fire between me and my goal. The more they stay there the more intense it is.
If you don't want to get caught in it you can align yourself with the goal so you are "running" with them. So, say it is a work scenario. You NEED space to work efficiently. Just provide them with a rundown. What you are working on and what it will take for you to get there.
"I am working on this which I think will really help to secure the *input end result*. I just need a little time to work out a few kinks, and will get back to you as soon as it is completed."
Then follow through. Eventually they will get a feel for how you work best.
If they are just on a power trip..... yeah, sucks to be you. Doesn't really pertain to type. That's more of an attitude issue.