Is it cheaper to bike?

Recently I stated that it was cheaper to bike to work (or anywhere) than drive. I based my statement on a GAO estimate that the operating cost of a bicycle was $0.05 a mile and the AAA estimate that the operating cost of a car was $0.26 a mile.  Some people disagreed with the GAO estimate (and I can no longer find where I got it from) so I wanted to figure out, is it cheaper to bike than drive?

First some ground rules. I am making all of the following assumptions:

1. I'm not considering the cost of ownership for either the car or the bike. No insurance. No car payments. No registration. No taxes. I think it's pretty clear that if riding a bike allows you to get rid of a car, it is financially advantageous.
2. I'm assuming you can park for free and you pay no tolls. If you have to pay for parking, I think biking again easily wins.
3. The mileage is the same whether you bike or drive. (Though for me biking is about a mile shorter because I go farther out of my way to catch highways).
4. I'm not counting health benefits for biking, nor am I counting social cost (environmental damage for example) or differences in safety. I'm also not considering time.
5. I'm not counting extra food you might eat when biking. Americans have weight to spare.
6. I'm assuming you don't use your bike for recreation of exercise.

Cost of operating a car.
This is pretty simple to find. I used AAA's 2005 numbers since they're automobile advocates and are unlikely to overstate the costs. They claim that a car depreciates at $0.2586 per mile. The cost of maintenance, tires, gas and oil ranges from $0.121/per mile to $0.152/per mile. I'll use the lower number. Add the two together and the cost is $0.3796/per mile.

Now let's assume you bike 14 miles each way like this guy. That's 28 miles a day for 240 working days. A total mileage of 6720 miles. That will cost you $2550.91.

Cost of operating a bike
This was a little more difficult to find. Some tried to say that biking was free. Or gave a number without an explanation. Just to play devil's advocate I'm going to pretend you need to throw out everything and buy it all new the next year. What will that cost?

Commuter Bike - $550 to $599 lets call it $600
Rack - $30
Light - $94
Tail light - $12
Trunk - $34
Bell - $9
Extra set of tires - $70
12 tubes (one a month) - $60
Multi-tool, pump etc.. - $24
A mid year tune up - $45
An extra set of brake pads - $8
1 bottle of chain grease - $14
Socks - $8
Helmet - $95
Shorts -$65
Pants - $100
Jersey - $40
Winter Jersey - $109
Gloves - $36
Winter Gloves - $28
Shoes - $95
Booties - $50

Now with anything else, you could spend more for these items. But you could also spend less and certainly this is all you need. Add it all up plus taxes and you get $1711.50 leaving you just under $840 to buy extras of anything, pay for extra maintenance and or even splurge somewhere in there. And, I know most of these things will be able to go 7000 miles without wearing out.  So I feel confident that biking is at least 1/3 cheaper than driving.

Comments

[Contrarian]

I think there are two problems with your comparison.

First, I think your depreciation number is way high. For the sake of comparison, I did a Kelley Blue Book search at www.kbb.com, on a car that I would consider typical of a commuter car at the end of its useful life -- a 1996 Honda Accord, in good condition, in a private sale. I compared two cars, one with 48,000 miles, the other with 104,000 miles -- the only difference is that one was driven an extra seven thousand miles a year over its eight year lifespan. The one with 48,000 miles is worth $4,300 and the one with 104,000 miles is $3,475 -- a difference of $825, or slightly under 1.5 cents/mile. I believe that this plus the cost of maintenance, tires, gas and oil is the true marginal cost of operating the vehicle. I'll accept the maintenance number, which brings us to around 13.6c/mile.

Second, even though your list of bicycle expenses is extensive, and is already up to 24c/mile, I still think you are underestimating the cost of commuting, especially everyday commuting in all weather. From my own experience as a 4,000 mile/year commuter, here is the rough lifespan of certain components:
Tires: 3,000 miles
Chain: 2,000 miles
cassette: 2,000 miles
pedals: 5,000 miles
Brake pads (rim): 400 miles
Brake pads (disc): 2000 miles
Headset: 4000 miles

I break spokes several times a year and probably trash a wheel about once a year.

A $600 bike is actually pretty cheap, and it's unlikely you'd make it through a 7000-mile year with the same wheels and crankset it came with.

If you're going every day, you'll need more than one pair of socks, shoes, shorts, pants, jersey, etc.

To get car-like reliability -- just get in and go, every day of the year -- you're going to need more than one bike.

The topic of expenses is endlessly debated in the commuting forum at www.bikeforums.net. The general pattern is that the longer you have been commuting, the more you are aware of the costs.

[Contrarian]

As a follow-on, I'll add that the low marginal cost of operating an automobile is a serious public policy problem. Once someone has made the decision to commute by car, the incremental cost on an individual basis of driving an extra ten miles a day or so is negligible relative to the fixed costs. However, on an aggregate basis those extra miles create a serious problem in extra pollution and congestion.