I don’t understand how car sharing can be profitable. You run into the same problem that public transit has—expensive vehicles with a long life offered to a people who could buy or lease their own car. While the cars are shiny and new now, in 5 years they will not be. Perhaps the zip-car’s of the world buy new cars regularly, and sell their old cars used.
On the other hand, the shared bike market looks better, especially considering that the two biggest players (from a quick search of the internet) are advertisers (JCDecaux and Clear Channel). They sell minicipalities a shared bike system in return for advertising space. The capital costs are low, and the risks are therefore minimal. Insurance is probably higher in North America with our crazy high speed limits in cities, but probably on-par with running a car sharing program.
And when you tot up the cost of going green, the bike share program really shines. A fleet of 10 electric hybrid cars would be a huge capital investment, and would help, oh, 20 people (being generous) give up their internal combustion engine vehicles. For the same money, presuming $40k per car (the Chevy Volt is supposed to be $35k, so add tax and more mark up and round off) you get $400k. How to spend this on a bike scheme? while the bikes are cheaper, you’d have to spend more on locking infrastructure. Still, supposing the costs are too outrageous, you could buy 200 bikes at $500 each and still have $300k left over for the “stations.” The DC plan charges a nominal fee of $40 per year per subscriber. The JCDecaux approach charges a few bucks per rental for an hour or so, then adds charges for more time, the idea being you can get anywhere you need to be withing a half hour, so keep that free and then get the bike back into circulation. Oh, and you’d need a van or two to help out with circulation of bikes (driving them back uphill!), so subtract $20k from the $300k for infrastructure.
At the very least, perhaps this could help people leave their cars in the parking lot when they go to lunch.
But of course, our roads in SoCal are designed for cars, not bikes.