They must have been doing more than 57 since that's what I was doing while being passed.. It's like "Hey look a Prius, lets pass it!"
So you were only 17 mph over the max speed allowed, and they were worse. George Carlin had something to say on the subject.
PriusTech is right in that a number shown on a yellow sign is a suggestion. A number shown on a white upright rectangular sign is a legal speed limit. That said ... I find, in my Prius, in good weather on a dry road, adding about fifty percent is stretching my limit of comfort. That could be 20 mph more if the yellow sign says 40. Adding 20 mph if the yellow sign says 20, or 15, is not as likely to end well. And I wouldn't go near that percentage with the road wet. (And that calculation is mostly about the risk of losing traction. It may not say much about how well you can react to something you abruptly see around that curve.) I've also noticed different states seem to use different safety factors in setting those suggested speeds. When first driving in California, I tried to treat their yellow speed suggestions the same way I was used to in the midwest. I managed to stay on the road, and learned to treat those California signs a little differently.
I don't think it's because you own a Prius. You are just now noticing that sweet Southern hospitality.
Pro tip: do not apply an "I can always go 20 mph faster" rule when the advisory speed is 20 mph. That would be 100 percent faster.
dang! i must have forgotten this from the drivers test manual 55 years ago, it is confusing though. download now i can picture them in several places, i always slow down at those signs. we have a quarter mile street with a white 25mph sign at the beginning of one end, and 30mph at the other.
