Speed Limit Or No Limit

Most of us have driven or ridden in a car, right?  Don't you get really aggravated when the speed limit is too slow?  I mean there are several reasons why we have speed limits, and I do respect that because if there was no limit then careless drivers would be worse.  But honestly, imagine if they had no speed limit, or they made the speed limit higher...Well they have, but where is that?What road should have a different speed limit, and what is your preferred speed?