I have been a proponent of higher speed limits on the Interstates ever since the Safety Nazis and the Anti-Destination League managed to get the 55 MPH national speed limit codified in law back in the 70's by manipulating traffic safety data. When setting speed limits was returned to the purview of the states, I, like many others, rejoiced. The dreaded and universally ignored nationwide speed limit was going to go away. Many others, including the aforementioned Safety Nazis and Anti-Destination League, screamed that doing so would create carnage on the highways at a level never seen in history.
It turns out that they were wrong, and not just a little wrong. They were a lot wrong. The carnage didn't happen. In fact, the fatality and injury rates went down.
Once allowed to do so, many states immediately raised their speed limits back to their pre-55 limits. Others, like my home state of New Hampshire, raised the limit to 65 MPH. The pre-55 the speed limit had been 70 MPH. Today the 65 MPH limit in New Hampshire is, for the most part, ignored. Most of the folks I see on New Hampshire's limited access highways are driving between 70 and 75, not 65. It's not just here in New Hampshire I see this, but in Massachusetts as well. Because of this I believe it's time to raise the limit in New Hampshire to 70 or 75 MPH. Let me tell you why.
Back in the good old days speed limits on major roads and highways were set a number of ways. One of the most prevalent methods traffic engineers used for setting speed limits on limited access highways was the 85th percentile, meaning that the speed limit was set for the speed that that at least 85 percent of the cars and trucks on that highway were traveling.
It has been known that people will drive at the speed that is comfortable for them, regardless of the posted speed limit. They will rarely venture above or below that speed because it makes them uncomfortable to do so. (It is one of the main reasons the 55 MPH limit was universally ignored: it was too damn slow for the road conditions and highway design.) Some have argued that raising the speed limit here in New Hampshire will only encourage people to drive even faster, to 80 or even 90 MPH. But that isn't true. Remember, people will drive at the speed at which they are comfortable. For most folks, it won't be 80 or 90. It is true that there are the few speed demons out there that will drive that fast, but they are doing that already with the speed limit set at 65.
Even if the evidence that increased speed limits hasn't led to hundreds of thousands of additional deaths and maimings doesn't change one's mind about increasing the speed limit, one must keep in mind that lower speed limits decrease the capacity of any given highway. Doing that at a time when traffic totals are going up makes no sense, particularly when it is unlikely that any new highways will be built any time soon. At best all we can hope for is upgrades to existing highways to widen them. Even then there are limits as to how wide they can be made and how quickly such upgrades can be completed.
Let's set the limits to more reasonable levels, one to which a majority of the motoring public will abide.
NOTE: I had started writing this Friday morning after reading the OpinionJournal piece about speed limits but didn't finish it until today. Then I find out Glenn Reynolds had already linked to the Journal piece, so I expanded the original post to include a more personal insight to the issue.