June 9, 2021–While goosing my truck up to 85 miles per hour on Interstate 10 West, I thought back to 1974 when the federal government forced states to drop all speed limits to 55 mph. This was done to 1) save fuel, 2) save lives.
It did neither.
This directly affected me, because during some of those years I was on the road as a musician. Driving 55 made for some long trips when we only had two days between gigs that took us from Fort Rucker, Alabama, to Sault Ste. Marie, Michigan.
States had no choice. Those failing to comply were prohibited from receiving funds from the Department of Transportation. It became another parable in the Realm of Unintended Consequences.
Ostensibly, this edict was a response to the “oil crisis” imposed by OPEC (Organization of Petroleum Exporting Countries) leading to the late 1970s rise in gasoline prices and subsequent lines at gas stations.
Did driving 55 actually save fuel? It’s not a simple calculation. Research showed that test drivers driving 55 on a closed track under ideal conditions could save as much as 20% compared to posted EPA mileage estimates. The trouble was that no one was driving under ideal conditions.
First of all, the 55-mph speed limit instantly became the most broken law of the land. Motorists learned you could goose it up to 64 mph and get past most radar guns. So we start with the concession that no one actually observed the posted speed limit.
In addition, most actual driving is starting, stopping, accelerating, climbing hills, and reacting to distracted drivers rather than cruising down a flat, windless, Buc-cees-free interstate highway.
The best estimate of documented fuel savings I found was 1%. Hardly worth 20 years of being late to everything.
As analysts began acknowledging these numbers, and as the oil crisis eased, states began clamoring for the limits to be lifted. This was especially true out west, where long stretches of two-lane blacktop beckoned.
That’s when the government came back with “55 Saves Lives.” Even if the lower speeds don’t save that much fuel, “isn’t saving even one life worth a few more minutes commuting time?”
The data show the exact opposite happened–traffic fatalities increased. The Cato Institute studied the effects of a 55-mph speed limit and found that after a few months of the legislation the country’s safety record was actually worse than had it had been before.
Accidents at 58 experimental sites where speed limits were lowered increased by 5.4 percent. Accidents at 41 experimental sites where speed limits were raised decreased by 6.7 percent.
Reasons for this again were complex, but mostly because, as we learned during Prohibition, people do not follow the law. Speeding continued. Ticketing went up. Law enforcement numbers had to increase, so costs to municipalities also increased.
Yet the federal government was undeterred. They even went so far as to have car companies print speedometers with a large 55.
Some states pushed back in passive-aggressive ways. Montana made the fine for speeding only $5. Drivers kept a stash of five-dollar bills in their glove boxes just for that purpose.
Eventually, rationality returned. By 1988, Congress allowed states to edge up their speed limits on certain highways.
In 1995, the National Highway System Designation Act returned all speed limit decisions to the states. Most went back to their original speed limits, while Montana had no speed limit at all for awhile.
Looking back, there are so many lessons we could take from this 20-year experiment. One is that you can’t legislate behavior.
It’s hard to believe that for two decades we endured an arbitrary federal law that we didn’t observe and that achieved neither of its main goals.
But we can take solace in knowing it could never happen again.