A few weeks ago, Clark wrote about truck drivers slowing down to economize on fuel. It’s a great story, but was it a real trend or just anecdote?
Well, I’m here to report that there’s some truth to it. Or at least some truthiness. A recent Congressional Budget Office paper examining the effects of gas prices found: “Freeway motorists have adjusted to higher prices by making fewer trips and driving more slowly.”
That’s surprising to me. I mean, I don’t slow down when gas prices are high; it would never occur to me. Do other folks?
But whether it occurs to anyone or not, it is a rational response to high prices, depending on the circumstances. As the paper explains, slowing from 70 mph to 65 mph reduces a typical vehicle’s fuel consumption by 8.2 percent. That adds up eventually, but whether it’s worth it depends on how much you value your time. (It also depends on how pricey gas is, and how efficient your car is.)
So the paper crunches some additional numbers—fascinating stuff I assure you—and finds that freeway speeds really did decline as gas prices rose. Not by much, mind you, but a little: about a teaspoon of fuel every 2.6 miles. There’s almost no way that the results are intended; it’s almost like individual irrationality adding up to collective rationality. And the paper sort of hints at that:
Such small responses are unlikely to result from concious calculations. Few motorists would have the information required to gauge their responses so acutely, nor the time or inclination to do so. However, higher prices make drivers pay more attention to speed. The modest reductions in speed suggest that drivers may have responded by easing off slightly on the gasoline pedal or dialing back the cruise-control settings a notch. If only a minority of drivers have that response, their reduced speeds could cause nearby drivers to slow down as well, even if gasoline prices alone would not have that effect.
The upshot, I guess, is that there’s an easy way to save the planet. Just reduce your fuel use (and everyone else’s), by getting in the left lane and driving 45 miles per hour. Folks may not appreciate you at first, but you can just hand them the CBO paper and talk about elasticity of demand. They’ll come around soon enough.
1) People tend not to think about it in our rush-rush society, but even over long freeway trip distances the difference in trip time between 65 mph and 70 mph isn’t great (~ 1/2 hour over 500 miles). For short trips it’s even less.2) Your joke at the end is funny but might be misleading. Assuming people DO place value on their time, there isn’t a linear cost savings return to driving slower. Assuming one places a linear constant value on time, trip cost is the sum (time total)(value per time) + (time total)(cost of driving per time). The dependence of efficiency on speed changes that second term but doesn’t affect the first term. Depending on time-value, fuel efficiency, gas cost, and aerodynamics there will likely be some speed that does minimize trip cost (for a given trip distance). A graph of y=1/x+x gives an idea of one possible shape.
There really is a slow car movement. At the UW Focus the Nation event, someone was giving out “Pace Car for the Planet” bumper stickers, and citing very compelling statistics about the ecological benefits of driving no faster than the speed limit. I can’t find his website now though.To the commenter analyzing the optimum speed, don’t forget the ecological impact of car accidents, whose frequency and severity should reduce with speed. Unless maybe you are in the left lane…
Just wanted to mention that Brussels Airlines is also slowing the speed of their planes to increase fuel efficiency. Couldn’t find a link but heard it on KUOW the other day.
“The upshot, I guess, is that there’s an easy way to save the planet. Just reduce your fuel use (and everyone else’s), by getting in the left lane and driving 45 miles per hour.”As tempting as it might be to force people to reduce their carbon footprint this way, it is illegal and dangerous. Quoting from RCW 46.61.100:”(4) It is a traffic infraction to drive continuously in the left lane of a multilane roadway when it impedes the flow of other traffic.”http://apps.leg.wa.gov/RCW/default.aspx?cite=46.61.100
I tried slowing down for years in my Subaru, but could never keep it up for long. Sitting in the slow lane going 55 when cars zoomed past at 75 just seemed pointless after awhile.Then we traded our Subaru for a Prius with the fuel read-out front and center. It not only shows instantaneous mpg…but also a bar chart for every 5 minutes, and overall total. My driving switched instantly. Many folks report the same thing.To me, having feedback in a challenge is everything. Toyota is considering adding these fuel meters to all their cars because their research shows people with them make significant improvements in their mpg.It is exactly the same with home electricity meters. Ontario…and now BC…are going to give every single electricity customer a FREE power monitor for their homes. Why? Experience shows that people with a home power meter in their living space make big cuts in consumption. It gives people control and instant positive feedback.If energy use is out of sight…well, it is out of mind.Now if we could just figure out how to make CO2 visible to everyone we might start making progress on climate chaos. I’m pretty sure if hazy CO2 clouds the size of houses where seen as they come out of cars and planes, we would be doing something about it. Oh, and the best kept secret to better mpg is to not accelerate uphill. In fact I now routinely lose speed gradually on long uphills…ending up at 50mph at the top of long grades. Think biking. If you are a Prius mileage geek, you’ll know this as essential to the big savings.Finally, I’ve noticed increasingly that cars will zoom up behind my Prius on freeway, slow down and tag along for a few minutes or sometimes much longer. I think people know there is a less expensive way to drive and are getting curious and dollar motivated. But without the “immediate reward feedback” eventually most can’t sustain interest in the “slow car movement”.
Josh, your point about Brussels Airlines slowing down to decrease fuel use is exactly right. And the fuel problems of the airline industry are a preview of coming attractions for drivers: both “slow” and “fast”.All airlines are in a desperate fuel efficiency race for solvency and many are losing. In April alone, Aloha Airlines, Oasis, Hong Kong Airlines, ATA, Skybus, Frontier Airlines, Champion Air and Eos Airlines filed for bankruptcy. Delta and NW Airlines reported combined losses of $10.5 billion in the last three months alone. That’s “billion”.Airlines are hemorrhaging dollars because of high fuel prices. They are trying everything from cutting on-board drinking water supplies to reducing food carts to buying lighter silverware to flying slower. They are planning large reductions in flights to force higher occupancy per plane.So why don’t airlines raise fares enough to survive? The reason: Airplanes, like cars, have a large range in fuel efficiency per passenger. Newer planes tend to be more fuel efficient. The difference can be huge. For example the atmosfair.de flight calculator shows a Boeing 707-320 uses 2.5 TIMES as much fuel per passenger than an Airbus A330-300 on a typical middle distance flight. It doesn’t matter how slow you fly the Boeing 707…you can’t make up the efficiency difference. Planes like this are just becoming too expensive to fly.And airplanes last a LONG time. It isn’t economically feasible to scrap the majority of gas hogs in the “used-airplane” fleet. See the automobile connection?So airlines with fleets of gas-hogs are going out of business because they have inefficient, expensive, long-lasting infrastructure. They can’t raise the fares beyond what airlines with newer planes can charge. They keep trying and they keep retreating. It is desperation time for those with gas hogs. (side note: this means that 5% of humanity than can afford to fly is being subsidized in this orgy of fuel consumption to the tune of billions of dollars. Smart climate policy??)Airline woes are fundamentally no different than the one’s facing the nation’s auto fleet: chock full of SUV and truck gas hogs. These also last a long time. Gas prices are getting so high that fuel cost is now the major cost of buying, maintaining and driving a vehicle. As gas prices rise higher we will see the same financial pain for drivers stuck with gas hogs. The difference? Brand new SUV/Truck gas-hogs are still being made by the millions. At least the airlines all stopped buying the worst gas hogs awhile ago.Our failure to restrict carbon consumption/emissions from new infrastructure purchases is going to hurt all but the most wealthy very soon. Investors are starting to revolt against the lack of carbon-transparency and hidden carbon-risk. As this slow car post points out, we all have huge carbon-transparency and carbon-risk liabilities in our own lives as well. Having the fuel consumption info hidden from us, whether in cars or home power or flying-dependent jobs/family lives, is going to cost us too.Likewise, many are finding that it doesn’t matter how “slow” they drive their gas hogs…they just can’t afford the best they can do with them. Many are heading for a forced “no car” movement.
Can anyone tell me how much gas you can save by dropping from 75 to 55 on 100 mile trips with a 6 cylinder car? I have done this for years on the interstate, because I am too cheap to waste my money on gas. Can you tell me how much I might have been saving over the past 10 years?
I’ve found that in our Honda Civic hybrid (which also has a mileage readout that one can reset on trips) slowing from 70 to 55 mph on a typical trip increases my mileage from about 38 mpg to over 50 mpg. I have tested this on trips where I’m rushed getting there (say to the airport) but not rushed getting back home. It’s an interesting and enlightening experiment!
The last statement is not funny nor should it be intended as a suggestion. Driving in the left lane intentionally slow is illegal, bad driving, and dangerous. One would only be leading a fast driver to cause a road rage incident. I’ve seen it many times: a slow, left lane driver being tailgated by an angry one and eventually passed, by the way using lots more gas when he/she floors it to pass the left laner.If you try and impose your beliefs on someone else, they will not follow you, indeed they will never. We have to demonstrate to all how it should be done by decreasing our own carbon usage. Oh and also the folks who we should be imposing our beliefs on are the elected officials. They need more input on what a crappy job they are doing about addressing climate change.
John T Schiffer Jr
God Almighty is not for road kill much less deaths!!!