Reset has written frequently about the benefits of both modern car-sharing systems like Zipcar and not-so-modern car sharing services like San Francisco’s creaky taxies.

New data generated by the University of California, coming to us by way of Sharable Cities, quantifies the benefit of the modern car sharing systems. The new study found that each car-sharing vehicle takes between 9 to 13 private vehicles off the road. And what’s more, this is just one more data point showing how taking cars off the roads puts dollars in our pockets.

The benefits of such reduction are numerous – from reduced air pollution to faster public transit times on less congested roads and even a happier and healthier population freed from the downright dangerous stress of long commutes.

But one of the most immediate benefits is the economic stimulus that comes from the savings realized by shedding cars. Depending on the type of car and your parking situation the cost of owning a car in San Francisco can be above $10,000 per year. The membership fees and costs of car sharing are a fraction of that – meaning that money that was flowing overseas to German carmakers or gulf oil producers is now sloshing around San Francisco, creating local jobs and more local tax revenues.

The economic impact of taxi-based car sharing is not as well studied, but there is growing support for the idea that a better functioning system means fewer private cars on the road. One of New York City’s leading tax experts noted recently that “a healthy taxi market gives people an alternative to private car ownership.”

The key word there is “healthy.” As our San Francisco taxi system wheezes along, this new study is one more reminder to the SFMTA that healing our ailing taxi system should be a top priority. And this authoritative study from UC is one more data point that car sharing generates substantial Civic Return on Investment.