Surprisingly enough, that tends to not be the case - http://www.sehinc.com/news/truth-about-speed-limits-explained-engineer http://www.sehinc.com/news/truth-abo

Surprisingly enough, that tends to not be the case - http://www.sehinc.com/news/truth-about-speed-limits-explained-engineer http://www.sehinc.com/news/truth-about-speed-limits-explaine... My personal anecdotal evidence on this, having recently driven cross country on I-80 (mostly 80MPH speed limits) and through Montana on I-90 (Again, mostly 80 MPH) shows that people drive at a speed that is safe for them. My car, and those that also seemed to drive a few MPH over the limit were all newer, highly capable vehicles, and the largest added risk was the chance of running into excessively slow moving traffic. When the visibility dropped, I slowed down, and when the visibility was clear, there was no additional risk in pushing it up a few MPH.