I agree that people will tend to not drive faster than what they feel comfortable at. I have even heard stories about places around my old town where they drew the lanes closer together (width and lane length) to make it feel like you are going faster to get you to slow down and it has had positive effects on how fast people drive.
However, people have vastly different "feelings" for what is comfortable. I've been in multiple different driving experiences in an awd subaru where I was going 30 under the speed limit because the weather was terrible and people were flying past me in their 2wd cars.
Shit, I even had an experience where I and literally 75% of other cars full on stopped on the side of a highway with our hazard lights on because we couldn't see more than 200 feet in front of us and people were still driving 30 mph past us.
I shit you not that was one of the scariest moments of my life because as the visibility got worse and worse, everyone starting putting on their hazard lights and going like 30, most cars turned off but we thought it was OK until the rain and fog got so bad the cars in front and behind us completely disappeared in the grey rain/fog. We drove for about a minute going like 25 MPH (I was slowing down to get more comfortable because I was freaking out) and I risked turning off onto the shoulder preying I didn't randomly ram one of the cars pulled off and we got lucky and were able to sit their until it got better.