A number of studies have attempted to put a figure on the reduction in vehicles that results from car sharing services. Research from UC Berkeley's Susan Shaheen goes a step further and quantifies how car sharing reduces driving. Even though most customers didn't own their own cars before subscribing, Shaheen found that the overall impact of car sharing is to lower all customers' vehicle mileage by about a quarter.
Chris Smith at Portland Transport spotted a write-up of Shaheen's research in the SF Bay Guardian, and it bolstered his belief that car sharing reduces driving because it makes the cost of each trip more transparent to users:
This article looks at car sharing, attempting to figure out how many cars are removed from our streets, and what the impact on VMT is.
The consensus is 9-13 cars per sharing vehicle (compared to claims of up to 32 cars).
But the really interesting finding is that there is substantial VMT reduction even though many car-sharing customers are from car-free households. The conclusion is that over time you learn how to use the car less and less, as you get better and better at using other modes.
That matches my personal, anecdotal experience. I think a big part of that is because when each car-share trip becomes an incremental expense, the pricing signals encourage you to think harder about the alternatives.
Elsewhere on the Network today: Biking in the Upstate explains how bike planning can help with "town-gown" relations. Urban Cincy announces that Cincinnati's form-based code zoning update earned a top prize from the Congress for New Urbanism. And the State Smart Transportation Initiative reports on the regulations that local governments are implementing in response to the rapid rise of the ride-sharing industry.
