Is Driving Better than Cycling?

Hey Mr. Green,
I always chuckle when I see articles like "Two-Wheeled Wonder" (March/April) make claims of bikes having "no emissions." A bicycle produces no greenhouse-gas emissions the same way my home heating and cooling system does: No emissions are produced on-site. But to claim that a bicycle is emission-free fails to take into account the emissions produced by making the bike and fueling its engine. Specifically, what powers my bicycle? Human muscle. It takes corn, beef, and a variety of other food fuels, most of which require the use of carbon-based energy for production. One might even make the claim that bicycling is less efficient than using an automobile given the resources needed to support my engine. --Philip

We've been through this sort of question before, with folks who wrongly think it takes more energy to make a hybrid car than it'll save. These ideas come from "life cycle" analysis, which calculates the cradle-to-grave environmental impacts of products. Such analysis is useful, but really it's making lots of you think way too hard for your own good.

Of course it takes some energy to make and propel a bike, but nowhere near what's required to make and propel cars that weigh 70 or 80 times as much and demand vastly greater energy for maintenance, from oil changes to tires to new fenders and grilles when they get banged up.

Some time ago in Sierra, I noted that the calories in a gallon of orange juice are sufficient to propel a bike rider approximately 48 miles. (Being a sexist wretch, I based the calculation on the caloric needs of an adult male.) Obviously, the energy required to create orange juice has to be included in its cost. So we can first test your theory with a cost comparison. Since propelling the average car 48 miles requires at least two gallons of gas (the average mpg for the U.S. auto fleet is around 23), the cost of the gasoline for the 48-mile trip by car would be around $7. Or about the price of a gallon of orange juice. If the energy alone required to make orange juice was really that pricey, nobody would produce orange juice. If you've got oranges, make orange juice.

Now orange juice is a high-end, high-water product. I only picked it because it comes in the same volume as gasoline and makes a cute comparison. If your cyclist settled for a humbler fuel, like cornmeal, he'd need about 1.25 pounds of it to propel him 48 miles, or less than a dollar's worth, even at trendy health-food stores and even with the escalating price of corn brought on by the ethanol scam. It takes a gallon or so of fossil fuel to produce 50 pounds of corn, so the amount of fossil-fuel energy needed to grow enough corn for the 48-mile ride is a meager .025 gallons. (Milling and transportation are excluded here, but I've also excluded the considerable energy needed to extract, refine, and transport petroleum.)

Even with pricier commodities like beef, the biker rides cheaper than the driver. A pound and a half of cheap, greasy hamburger, sans bun, could power the cruise in question, at a lower cost than gasoline.

The ethanol "alternative"? Well, not really. Instead of burning ethanol in engines, from a transportation standpoint we're far better off ingesting the stuff. Driving 48 miles takes more than two gallons of ethanol, whereas only eight ounces of liquor, a mere half-pint of vodka, can fuel a cyclist for the same distance. Happy trails! [Editor's Note: As pointed out in the comments below, Mr. Green gets more out of his tipple than is mathematically demonstrable. In fact, his vodka-fueled half-century would require 29.5 ounces--that is, a fifth plus four shots. Good luck staying upright after that.]

Comments

[Michael Fox]

One thing that that makes the whole notion of driving being better than walking moot, is that you should be eating the SAME amount of food whether you are walking or driving, the only difference being that if you walk, you just might happen to lose some weight! When you drive, all that energy used is therefore 100% additional to any food energy consumed.

[Cosmo]

Ah, but what about longevity considerations?

Karl Ulrich at the University of Pennsylvania claims that because cyclists tend to live longer than motorists, their reduced impact is inflicted over a longer period of time, thus negating its Earth friendliness.

I've never been swayed by it, but I can't exactly disprove it, either. Thoughts?

-Cosmo
http://cyclocosm.com
http://matternetwork.com

[Nick]

8 ounces of vodka, at 65 calories an ounce, gives us 520 calories - not even close to the 1,950 calories in 1 gallon of orange juice or 1.25 lbs or cornmeal. You would need 30 oz of booze - about 1/4 gallon.

That said, it seems from casual observation that America has a massive, untapped energy reserve - fat. At 3,500 calories per pound and 20 lbs overweight, most of us seem to have at least 36 of the afore mentioned trips already stored up, without even needing a single additional calorie. Put another way, you could bike commute 20 miles round-trip to work for a third of a year on those stored-up energy reserves (5 days a week for 87.5 working days). That saves ~70 gallons of gas (at 24 mpg) with zero collateral damage.

[Grishnakh]

This is all ridiculous.

First, the idea that a hungry person could drink a gallon of orange juice and then bicycle 48 miles is utterly ludicrous. Regardless of the energy contained in juice, humans are not very efficient at extracting that energy and putting it to any use. In fact, most food energy we consume is used simply producing heat, to keep our muscles warm, like any mammal.

Second, to "Cosmo", fat people can't simply not eat, bicycle a few hundred miles, and lose weight. The human body again doesn't work that way; such a person would probably die after 10 miles or so from exhaustion.

While it's certainly true that an in-shape human on a bicycle uses far less resources to travel any distance than any kind of existing car, throwing out numbers like these only makes you look like an idiot.

However, it may actually be more efficient to travel in a car in the future, if we ever get to the point where we have pure-electric vehicles with excellent battery life, powered by solar panels on our homes' roofs. Solar power can't exactly be used as fuel by human bodies, and most of it is wasted anyway, either going off into space, heating our rooftops and asphalt, etc. Harnessing it with solar panels and powering cars would probably require less resources than feeding a human.

[Kennedy Signal]

@ Grishnakh
You're a fat person, aren't you? :)

[zheem]

When I do the math, vodka has four times as many calories per oz as orange juice, so it seems reasonable to say that 1 gallon of oj would equivalent to two pints of vodka. I'd rather try to ride 48 miles on the orange juice, though. (And I think I could, actually.)

[Tim Paton]

Do you really believe that Joe Average Cardriver, living on a diet of drive-through fast food and sugar-based soda drinks, would need to increase his energy intake in order to cycle 5 miles to work instead of drive?

Most people in developed countries eat a massive surplus of energy.

We're fuelling the "engines" of half a billion potential cyclists in North America and Europe, whether they're riding bikes or not. Any suggestion that cycling causes increased emissions due to the fuel demand is absurd.

[Ruth Busch]

When I was younger (35 or so) in the '60s, I used to bike 3 miles to the U of Ariz. from my house. People driving past would yell,"How's your mileage?" "Three miles to the martini," was my answer. Tee martoonies, 3 miles in and 3 out.

[Paul]

Nick misses so many points in the discussion that I have a image of him as a spheroid.

No one suggested that a person bicycle 48 miles powered only by orange juice. However, by drinking 8oz. (1/16 gallon) he could travel three of the 48 miles on the orange juice and use other foods/fuels for the other 45.

No one suggested burning all excess fat before having another meal.

There's nothing idiotic about using a few analogies for comparison purposes. They are intended as food for thought.

Human bodies use solar power for fuel all the time. It has been converted into food by photosynthesis.

[Paul]

My apologies to Nick. It was the post after his, by Grishnakh, that I responded to.

[Paul]

My apologies to Nick. It was the post after his, by Grishnakh, that I responded to.

[Paul]

My apologies to Nick. It was the post after his, by Grishnakh, that I responded to.

[Helena]

If technology can produce a vehicle that weighs about 18lbs, easily lasts 10 years or more, and has an peak output of about 1-2 horsepower... then maybe technology can approach the efficiency of a decent bike powered by a healthy person.

Vehicles transport the person in the vehicle while the person consumes resources directing (and maybe powering) the vehicle. If the vehicle is powered by fossil fuels or by orange juice it still requires more power to move a 4000lb vehicle plus 160lb occupant than it does to move an 18lb vehicle plus 160lb occupant.

I don't advocate everyone get and ride a bike as a sole means of transportation, but for trips 3-4 miles or less it is not only more efficient, it is often faster and more convenient, less expensive, and shows far more grace and poise than even the nicest car. So I guess I am advocating it. ;)

[surfzombo13]

lol, and remember, the folks driving the car are still going to be consuming food, which is definitely not going to powering any kind of means of transport.

[John Satchell]

What would happen if you mixed the 1 gal of OJ and Two pints vodka and drank them all the way to and from work.
Would it make it any easier or more fun? I'd bet it would

[Bekir]

There's another advantage to not driving. You can escape traffic instead of being held captive.

- Bekir

[Rick]

What about the resources "burned" to medically treat the obesity epidemic?

Or the resources "wasted" on a stationary bike at the gym?

[solamic]

I think bike commuting is a good thing (did it yesterday), but I do worry that for most people in America the environmental and dollar costs of building the bicycle and maintaining it, per mile, are more than for a car. This is a usage problem not a theoretical problem. If one were to ride a bicycle every day this would not be an issue, but most bicycle owners I know in America ride their bicycles infrequently, say once every other month on average. There are many more bicycles sitting gathering dust in garages than out on the street and trails. Adult bicycles are designed and sold for occasional recreation here in the USA, not for daily use. I have no actual figures, but just to make some estimates lets say the average American bicycle costs $250 to buy, lasts 5 years before going into the landfill, and is serviced say four times at a cost of $50 per service. If they ride 15 miles every other month that is 450 miles over the bicycle's lifetime, for an ownership cost of about $1 per mile (not including fuel), much more than an automobile. It seems to me that the environmental costs of building the bicycle and then having it end up in the landfill are greater than the environmental costs of driving an existing car 450 extra miles. In other words most car owners in America don't help the environment by owning and occasionally riding a bicycle. Folks that ride often do come out way ahead, but they are unfortunately in the minority.

[C]

well, neither side really delves into a real analysis of the energy production costs for a particular span of travel.

using the calories concept for the humans is good, but then you have to factor in the cost per-gallon of orange juice: fertilizer, man-hours of labor, production, transportation to retail, pickup, and consumption.

for gasoline, you have to factor the energy required for extraction (pro-rating the facilities cost), transportation, refining, more transportation to retail, pickup and consumption.

i think the bicycle would generally win out depending on geography and the type of calories consumed. a 1/4lbs of beef might end up being similar to gasoline.

supply chains are very complex beasts!

[peteathome]

But I think the concept of this analysis is very clever - in general, the market is not going to let the cost of the food be less than the cost of the petroleum products used to produce it. So if the foodstuff needed to bike X miles is cheaper than the cost of fueling a car that distance, you can bet the bicyclist is using less gas.

Regarding resources to build an infrequently ridden bike - sure. But, on the other hand, you start using that bike for your short trips, it will very quickly pay for itself.

While I don't like the quality of these cheap bikes, a coworker I bike to work with has been using a cheap budget bike for about 15 years. He has at least 30,000 miles on it and it is still going strong.

Of course, he has replaced tires, brake pads, chains and rear cogs numerous times, not to mention a failed crank, a rear wheel and other parts. But I still best he got his "carbon footprint" value out of it!

[Milk Run]

Unfair comparison: Car vs Bike
A 50cc scooter would be a much more relevant comparison. The scooter would also have the same benefits and drawbacks of the bicycle.

I would like to know how far a 50cc scooter could go powered on half a liter of ethanol.

[el serracho]

Dear Mr Green,

are people effing stupid or what?

yours,

el serracho

[Aaron Bockelie]

The direct comparison of how many calories are in a gallon of gasoline, which is approx. 31,520 kCal per us gallon for regular unleaded fuel per gallon of orange juice, 1,950 calories. While taking up the same amount of volume, the energy density of gasoline is far higher than the orange juice, which is why your comparison of a 48 mile trip.

Again, comparing the kCal energy equivalent content of gasoline vs. orange juice, you're looking at orange juice being nearly 16 times more expensive as gasoline from a strictly caloric value. (obviously humans can't drink gasoline and derive any energy from it)

Keeping that energy value equivalent in mind, consider the vehicle weight comparison, let's compare the ultimate efficiency between a car and a bicycle:

We'll use a Subaru Forester for the car, with an average mpg of about 24, with the subaru running on regular unleaded and the bicycle rider running on a gallon of orange juice over 48 miles.

Subaru Forester: about 3300lbs (720 lbs 4 passengers) = 4020lbs @ 1313 kcal per mile

Bicycle: about (180 lbs rider + 25 lbs bike and gear) = 205 lbs @ 40.625 kcal per mile

weight sigma (car larger number): 19.6 (4020/205)
kcal sigma (car larger number: 32.8 (1313/40)

weight/kcal sigma (bike on top): 1.6

So, a bicycle from a strictly caloric intake is approximately 60% more efficient than a bicycle rider from a strictly caloric intake.

But wait, the car has 4 passengers, so divide by 4, and now you're noticing that from a caloric standpoint, it's far more efficient to transport four humans by car than bicycle.

All this mathematical posturing really doesn't give us any solutions though. If we all carpooled 4 people to a car and rode bicycles to work for short distances, we'd be way the hell better off than we are now.

And maybe until we can figure out how to pack 31,250 calories worth of orange juice into a 1 gallon container, we're probably better off not comparing bicycle riders to car drivers.

[Travis]

I fail to find the argument compelling.

We are going to eat pretty much the same thing whether we bike or drive. If everyone carpooled, perhaps the argument would make slightly more sense.

But no one carpools.

[Budro]

While this argument is all fun and games...what is not addressed is that your average comuter does not live within reasonable biking distance from their occupation. The point being that no one in their right mind is going to spend 2-3 hours on a bicycle to cover the same distance in their vehicle in 15-20 minutes. This does not even bring into play the relative level of energy one would have at work or other destination much less the viability of the return trip.

I salute all those who are able to do so, but biking is not feasible for most for a variety of reasons.

[el serracho]

Budro,

the average commuter who does not live within reasonable biking distance from work is an idiot. and if it takes you 2-3 hours to bike the same distance you can drive in 15-20 minutes you are driving too fast.

biking is not feasible for people who have crafted idiotic lives for themselves. anyone who's reading a frickin blog on the sierra club web site should have the sense to order their lives in such a way to minimize the amount of time they spend in a car or stop complaining about the cost and time.

living in cars just doesn't sound like a very fun life.

yours,

el serracho

[Ned]

I ride a bike everyday to work. I ride my bike because it's cheaper than gas and it keeps me fit. I still eat the same amount of food I've always eaten, some meals I eat less. The benefits I receive from riding my bike outweigh any type of comparisons. I have plenty of extra cash and no beer belly.

[David Johnson]

"the average commuter who does not live within reasonable biking distance from work is an idiot."

Or someone who can't afford the rents/costs of living that close - nor find a job closer. In Real Life (TM) it's not always easy - or even possible - to do this.

Anywho, in practice, if the only way to continue to commute in this country is by bicycle, then soon very few of us will be able to afford bicycles...

[Tracey Price]

I've been commuting by bicycle for 17 years during warm weather months & I eat no more then if I go swim before work or go to the the gym. It's ridiculous to say "that I'm consuming more energy then it takes to power a car". When the human body is well tuned it functions well with very few added calories.

Ciao,

Tracey P

[Tracey Price]

Also I commute 15 miles round trip per day & it takes me 1 hour. I used to commute 26 miles & it would take 1 1/2 hours, so no excuse for not riding if your physically able. I do think must americans are lazy & can't bear discomfort of any kind & thats why we have cars & air conditioning.

[Dan]

So why isn't anyone talking about pedal-powered busses with everyone pedaling as they're able, maybe each with their own shift lever? And why aren't pedicabs a growing business?

[Fran Taylor]

Don't forget to calculate the resources necessary to manufacture and recycle the car and the bicycle.

And the spare parts, too. Cars chew up engines, transmissions, tires, windshield wipers, filters, oil, etc. in addition to gasoline. Bicycles need new tires, brake pads, cables, chains, etc. but this is far less than a car.

[Fran Taylor]

"easy" and "possible" are concepts that can change meaning pretty quickly as the price of gas goes up and up.

When gas gets to $8 a gallon, 'impossible' becomes 'maybe I should have starting thinking more seriously about this a while ago'.

[flower power]

you're all idiots

[Bosco]

@David Johnson

You have to figure in the cost of your daily commute when calculating affordability. In some areas it works out to be cheaper to live in a more expensive near where you work, but without the transportation costs. Look here for a more thorough analysis:

http://www.worldchanging.com/archives/007963.html

What we need today is more solutions and fewer excuses.

[Jeremy]

The big failing with cars is that they transport a couple tons of extra weight. Thus any great 'efficiency' gains (like solar) could be magnified by applying them to smaller vehicles.

The 'average' American is overweight, and many are trying to lose weight. Thus a more appropriate comparison would be 'energy' consumed building and riding a bike vs. energy consumed driving, building gym equipment and traveling to the gym. Alternatively, you can look at calorie consumption and weight. If we assume a bike rider needs a number of calories above their "baseline" requirement and a gradual weight loss, then eventually, the total calorie requirement could be less than a driver (especially one with gradually increasing weight.)

As for production costs, it would be interesting to see lifetime cost/mile of various bikes and cars. I had spent about $1000 on my previous bike and logged more than 5000 miles before it was stolen. My minivan would need to log about 150000 miles without any additional service costs just to equal that rate. And this doesn't include fuel costs for either.

Then there are infrastructure costs that are external to the calculations. A travel lane for a car takes up more space than a bike lane, and will wear faster (due to the greater weight of cars) Car parking spaces also consume much more area and materials than bike parking spaces. Extra space enables things to be located further apart. Greater distances thus encourage faster travel time, which encourages more freeways and other travel lanes. This in turn requires things to be even more spread out, thus increasing travel distances. (Bikes due consume more space than pedestrians, but not near as much as cars.) Roadways also require soundwalls, landscaping, buffers and other features to minimize the local impact.

From a vehicle perspective, cars and bikes allow traveling greater distances with ease. This benefits the individual, but as society adapts, the distances become the norm, and the vehicles become required.

[Tove A. Elfström]

I have a couple of comments regarding bicycling and fuel and costs. My first one is just a quick one: I would not recommend anyone to use ethanol, first of all, and especially not in traffic. Some think it is a joke, but anyone who has lost relatives to drunken drivers don't. Had alcohol been invented today it would have come with numbers of resrictions.... Traditions are powerful, however!

Jacques d'Iribarne published a book in the seventies where he discussed the cost of the mile on the road. If you add the hours you have to work extra to afford, say a car, to the time you use it and then divide the # of miles by the # of hours spent (driving and working extra to pay for gas, repairs etc.) you arrive at a different mph. Ususally, in a city that mph approximates the speed of a bike! But you can do this for a number of convenience items and things get really interesting. Please keep me posted to comments to this as I am interested in a critical assessment of my posting.
Thanks,
Tove A. Elfström

[Eric Fosburgh]

I'm probably preaching to the choir here, but I've been walking to and from work for 10 years now and despite all my excessive food and alcohol consumption, I'm pretty fit. I haven't done the math, but I'm quite certain that my suburban coworkers - they all like to eat and drink too! - who all drive at least 30 minutes each way daily are using way more fossil fuels than I am...

Eric
in beautiful Seattle

[Joe]

31,250 calories of orange juice may be bulky, but a gallon of olive oil contains over 35,000 kcal. Yummy!

[Seyra]

I feel like we are missing the point to this article. Even if you bike instead of drive just a few times every two weeks, you are saving gas, money, and therefore lessening your impact of greenhouse gases into the atmosphere. The production of a car takes much more energy, labor than does the production of a bicycle. ALso, the longevity of a cyclist rather than a person who only drives is just another statistic put out there that makes us have these conversations that don't get us to finding the solution of the problem. If you are conscious of your actions, and use that consciousness to display your lifestyle to others, that's great, but we also know that many people don't have the choice to choose a bike rather than a car, or to walk rather than ride a car/bus. This is where we need to lay our attention. How about we make it more available for people to be able to take part in these "green" methods of transportation, and make it convenient enough that people won't say no. Partaking in sustainable, or "green" transportation shouldn't just be for the "fortunate", but for all.

[Cynthia Dietzel]

It sounds like the Bike rider could benifit from some cayane pepper to keep from drinking so much... Look on the web search for the "PDR for Herbal Medicine" or go to the book store...

[Josh]

Cynthia, if you're suggesting that bike riders should drink less alcohol, then you don't know bikers very well. Mountain bikers could probably stand to smoke less pot, though.

[Elaine]

It's a cute mathematical problem, but you have to eat, regardless of how you commute. So you can either consume both food and fossil fuels by driving, or you can consume food but stop consuming fossil fuels by biking and not driving.

This argument sounds similar to the old math tricks of finding a roundabout way to "prove" that 2+2=5. Sure, it stretches your brain functions, but it's so obviously wrong that who could take it seriously?

[hpavc]

wtb math for car with multiple people

[Electric Scooters]

Thanks for sharing this information! I believe that scooters are one answer to the growing problem of pollution and global warming! They are perfect for commuting within a city, or for any short trip. I also have a website about scooters that you may wish to check out. Feel free to visit at: http://www.electricscooteroutlet.com Thanks again!

[Zed]

With all due respect, Budro, my commute by car is 20 minutes whereas my commute by bike is 40 minutes. The bike commute is also slightly farther (using lower-traffic roads). My total distance is approximately 9 miles by car, 11 miles by bike.

That's hardly unfeasible.

Just remember to pack a stick of deodorant for when you arrive.

[Vintage Schwinn cycles]

If I could go 48 miles on an orange I wonder how far I could go on a banana. Seriously though, I used to cycle to college everyday and was the fitest I'd ever been. I swore I'd never have a car and that I'd cycle everywhere. Two years after that I discovered my freedom and bought a car. Thanks for the enlightening article.

[Bubba]

All of you who say that riding a bike for a hour or more each day doesn't require an increase in caloric intake are clearly wrong. The increase is rather substantial. You will also need to increase your intake of protein along with your increase in calories.

You don't need to travel four to a car to beat a bike in fuel efficiency either. Two people in a small car (35-40 MPG or so) should be sufficient.

Did I mention that the car is faster and safer?

[online car insurance]

Ignorance is one thing, stupidity is another...

Basically, when comparing carbon footprints between a car with its driver and a bicycle with its cyclist, you don't gain any reasonable leverage by arguing the cyclist consumes more corn, meat, food, etc. Heck, wouldn't the car driver also do the same while eating a corn dog and drinking a starbucks coffee while driving?

[Phnepsilon]

I would like to point out that the more physically active you are, the faster your metabolism is. The faster your metabolism is, the more calories you're going to end up consuming. So, Eat more food, move to the top of a hill with interesting stuff at the bottom,roll down, and take public transit back up. /That's/ how you can maximize efficiency.