The Mayor visited France and came back with the idea of the city renting bicycles. You can read an in-depth article here on the success of this type of program in Europe. But we don't live in Europe and if you read further down the article, you'll see what the motivation really is. Washington, D.C. is about to launch a program called SmartBikeDC:
"Clear Channel Inc.'s Adshel, an outdoor advertising and furniture company, will administer the project. The company is no stranger to bike sharing, having launched the programs in Rennes and Barcelona, among others. Clear Channel will give Washington, D.C. $153,000,000 and a share in its advertising revenue as part of a broader 20-year bus shelter deal that treats public bicycles as an amenity."
Check this out for why Share-A-Bike European style won't work here. We've had Share-A-Bike, Chicago-style for a long time.
Scratchin' My Head,