July 14, 2008
"It took me sixteen hours to get to LA"

Virginia Senator John Warner's proposal to reinstate a national speed limit is back in the news.

[Sen. Warner] says it's time to start the conversation about an energy-saving national speed limit to help spare Americans from usurious fuel costs.

The 55-mph limit was imposed by federal law during the energy crisis of the mid-1970s, remained in effect for 20 years and ultimately was booted off the roadways by Congress in 1995 amid near-universal contempt among motorists.

Warner hasn't specified what a new limit should be, but he points out that Americans saved 167,000 barrels of petroleum a day when the 55-mph speed limit was in effect. He told fellow senators this week that he'll probably proceed with legislation after the Energy Department determines the most fuel-efficient speed limit for the nation's highways.


In Congress, the idea of reinstituting a national speed limit was below the radar for most lawmakers until Warner began endorsing it. Many lawmakers are likely to be unwilling to resurrect any variation of a highway rule widely condemned and ultimately ignored.

"It's not a real solution," said Sen. John Cornyn, R-Texas.

Sen. Mel Martinez, R-Fla., said the 55-mph limit "didn't work so well the last time," though he acknowledged that it would save fuel.

Well, if the goal is to use less oil, then it clearly is a real solution and it did work pretty well last time. The fact that many people routinely ignored it is certainly a concern, and I for one would have far more qualms about creating more opportunities for traffic stops now than I would have had 35 years ago, but the plain fact is that we as a nation consumed less oil with a 55 MPH speed limit. Just about every other scheme you can think of, from "Drill here, drill now" to the Pickens plan, would take years to have any effect. Lowering the speed limit would reap benefits almost immediately - basically, as soon as you could get the signs up - and it would be a boost to the environment and public safety as well as being dirt cheap. I don't believe for a minute this would actually pass - the Republicans clearly aren't interested in anything that involves conservation, and the Democrats are way too chicken to push something like this through; even if they did, Bush would veto it in a heartbeat - but let's not pretend that it wouldn't do any good.

Posted by Charles Kuffner on July 14, 2008 to Planes, Trains, and Automobiles

167,000 barrels per day? That was back in the 1980s? So maybe we would save about 250,000 barrels per day in 2009. The U.S. uses 21,000,000 barrels of oil per day, so we'd be saving about 1% of our oil. Is that worth it, considering all of the side effects that go along with this including reduced economic activity and
disregard for the law in general and contempt for law enforcement? I don't think so.

Many people are already VOLUNTARILY changing their driving habits, either by driving less, carpooling, or slowing down a bit.

Posted by: E.P. on July 14, 2008 9:40 AM

I must admit that abolishing the 55 mph speed limit was one part of the Republican revolution that I liked.

Posted by: Ron in Houston on July 14, 2008 11:07 AM

I drive 50 miles/day, mostly on the Gulf Freeway and south loop, and the average speed has definitely slowed down since we got close to $4/gallon. I have my cruise control set at 63 (vs. 67 3 months ago) and I am still one of the faster drivers on the road.

And my mileage is much better.

I don't think I'd feel safe at 55 unless a lot more people (ie, TRUCKERS) were also going that slowly. Maybe that's where the political issue is, in the trucking industry.

Posted by: karen on July 14, 2008 4:24 PM

The idea is a joke.

In 1974, vehicles traveling faster than 55MPH started burning additional fuel to go faster. With today's modern fuel injected, computer controlled engines, overdrive transmissions and such, the "economy curve" doesn't see a decrease in efficiency until somewhere above 85MPH.

That said, we will burn more fuel setting in slow moving traffic than we would ever save by such a reduction in speed.

Posted by: Michael W. Jones on July 14, 2008 10:34 PM

@ Michael W. Jones
Cars still burn gasoline to go faster. When you press on the gas pedal more fuel is going to the engine. That hasn't changed. The primary obstacle to fuel inefficiency at those speeds is wind resistance, not engine efficiency. Cars have become more streamlined to reduce wind resistance, but I bet there's still a significant fuel savings to driving 55 or even 65 versus 75.

Posted by: markcov on July 15, 2008 2:52 PM
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