
Analysis Overview
To start, I need a baseline cost of personal car ownership, which obviously varies widely. Depreciation rates, maintenance needs, insurance costs, parking, fuel prices, and driving distance all differ for individuals and their vehicle type. But a few sources like the American Automobile Association and Kelly Blue Book offer a similar ballpark average for newer cars nationwide: about $8,500 per year. That’s across all types of communities in America, so for this analysis I’ve rounded it up to a simple $10,000 to represent an urban area like Seattle with higher fuel costs, paid parking, slower commutes, bumpy roads, and many voter-approved vehicle taxes. A related statistic: personal cars are unused and parked for 95% of their existence. Compared to the value of new cars (in the range of $20,000 to $30,000 or more) we sure don’t use them much. The numbers above only reflect the individual costs. The analysis will not account for the unpriced externalaties of air and water pollution, planetary climate change, congestion, urban sprawl, public health, and traffic injuries and deaths. I and many other experts have written plenty about those problems already and the research is freely available. For this analysis, I’m only focusing on one thing that greatly influences people’s lifestyle choices: their wallet. My analysis starts by accounting only for long-term rental trips–that is, trips that are most similar to the benefits of car ownership: flexibility in schedule, predictability in parking location, and opportunity for spontaneity in route and destination. Therefore, I did not include car2go and ReachNow trips because there was no guarantee of a vehicle being reasonably available. I also excluded Lyft trips because most of them could have been replaced by transit, I don’t use it to travel outside the city, and in many situations I was not in a condition to drive (happy new year!). What it comes down to is mostly my Zipcar trips. Zipcar is an American car-sharing company founded in 2000 and based in Boston. It was bought by the traditional rental company Avis Budget Group in 2013. The company has one million members and 12,000 vehicles in over 500 cities around the world (Autoblog reports membership is growing a massive 10 percent per year).

The Data
Now, the data you’re looking for. Details on trip date, destination, and purpose have been generalized for privacy. See the Notes section at the bottom of this post for details on exclusions and other circumstances.
I averaged about 2,000 miles and 16 trips per year (1.25 per month). I burned approximately 53 gallons of gas per year, resulting in annual carbon emissions of one-half ton. The rental costs averaged about $800 per year, which is less than 50 cents per mile.
The Results
The $10,000 annual car ownership cost established above is based on an average 15,000 miles per year but is largely locked in by depreciation, insurance, taxes, and financing. However, part of it is variable by miles driven. Accounting for all of this and sparing the dry calculations, at a minimum I’m saving an astounding $8,000 annually. This is remarkably consistent with the savings Zipcar reports from its membership. $8,000 is a huge a portion of my income. If I wanted to own a car but save the same amount elsewhere in the budget I’d need to string out my student loan debt many more years or cut my rent in half, which is nigh-impossible in the Seattle housing market. Owning a car would doubtlessly be a net financial loss–not to mention the effects on my carbon footprint and chance of serious injury.

Going Forward
According to Zipcar, a “Transportation Research Board/National Academy of Sciences study finds each shared car takes about 13 private cars off the road”. The expansion and diversification of car-sharing services has massive implications for the built environment and ecological resiliency. More access to this transportation option–along with more robust opportunities to walk, bike, and ride transit–will allow for more compact and livable communities. Cities can shape this type of future by prioritizing the availability of shared cars on public streets and reducing or eliminating minimum parking requirements, especially for residential buildings in established neighborhoods. They can also get creative where parking is built: In Vancouver, B.C., developers may substitute one long-term shared car parking spaces for five private parking spaces. Cities can also help promote shared car services and educate the public on the benefits of living car-free by presenting the financial, environmental, and health data that supports it. It’s not for everyone; some long commutes, job requirements, and family obligations simply aren’t practical on the bus or train. But if even a fraction of a city’s population voluntarily adopts a car-free transportation style the positive impacts can be many, among them lower emissions, better air quality, safer streets, and less expensive housing. If you live in a transit-rich and walkable community with car-sharing services and you consider yourself a steward of the environment, I encourage you to think about ditching your car. Not only will you spend less time searching for a parking spot, it’ll put money in your pocket and will help make your community and our planet a healthier and happier place. I’ll be updating this article with new data annually. Feel free to ping me with questions about living car-free. Notes:- The data includes three traditional rentals through Enterprise.
- I’ve excluded the considerable number of business trips I’ve done with Zipcar. My employer agreed to reimburse the rental fees (and occasional tolls) when I demonstrated the benefits over traditional car rentals. The arrangement is roughly equivalent to being compensated for personal car use.
- I’ve also excluded personal trips that originated outside of Seattle, such as when I used Zipcar for sightseeing during trips to Denver and Los Angeles.
- To reflect true individual costs I’ve noted where the trip expenses were split. Some of the trips go back so far I can’t find a record of the trip purpose and who I was traveling with, so in those cases I assumed the costs were borne only by me.