Actually, this is a potential reason not to increase the speed limits. Not because people are too stupid to accelerate on them (which they are), but because some of them are so short as to make it difficult to accelerate to traffic speed before being forced to merge now.

This right here is a big problem in Colorado Springs at one intersection. It is under construction and the entrance ramp is rather short, due to a bridge shortly after it forcing people to merge (5 lanes on the bridge right now and the median, bridge will eventually hold 3 normal lanes). Speed limit in that area is 45, but people average 65-70 due to it being about a mile away from where the limit was 75 for those traveling between Colorado Springs and Denver.

Police set up speed traps there with 4 motorcycle cops and have no downtime. After seeing some of the accidents there from people unable to go anywhere when things go bad, I always slow to 50 max, and usually sit in the left lane. It's pissed quite a few people off, but it prevented a few people from causing more accidents.