Users would likely pay from $75 to $125 a year to join the system, with lower daily and weekly rates for tourists or others who want just to try it, according to preliminary financial projections.
Registered users would be issued a membership card with an electronic code that would allow them to remove a bicycle from any station, use it as desired, and return it to another station.
Extra charges of $20 or $25 would discourage members from keeping bikes overnight, according to Andrew Stober, chief of staff to Rina Cutler, deputy mayor for transportation and utilities.
"The system's not intended for that kind of use," Stober said. "We expect the average trip would be just a mile and a half. Most people are not going to bike more than three miles. It will take too long, or you'll get too sweaty doing it."
In Washington, Capital Bikeshare has been operating for three years, with members recording more than four million trips. To encourage short trips and keep the bikes circulating, the bikes are free for the first 30 minutes and cost $1.50 for the next half-hour, with escalating rates, up to $12 an hour, for longer trips.
New York City launched its Citibike program at the end of May - sponsored by Citibank, which spent $41 million for naming rights - and already has 70,000 members putting up $95 a year each to join, Stober said.
Philadelphia has not yet decided on its fee structure. The city is soliciting business sponsors, who would pay to locate bicycle stations near their companies, and hosts, who would be willing to put stations on their property free.
Within a couple of months, Stober said, the city expects to put out a request for proposals from companies interested in managing the program.
In a news release, Mayor Nutter described the project as a relatively inexpensive way "to create a new form of convenient, affordable, and healthy public transportation."
The city has $3 million in its capital budget to get the program off the ground and expects to raise an additional $10 million to $12 million from state and federal grants and private sponsors, using the money to build the network of secure bike stations and buy specially made bicycles. The bikes the city wants are designed to be sturdy, not fancy - and unattractive to thieves, because the parts will be incompatible with other bikes.
Officials are hoping to begin implementing the program next summer, with installation of bike stations in a limited geographic area, including Center City from river to river and extending across the Schuylkill into University City. Member sign-ups and usage would likely start in the fall of 2014.
It would take to the fall of 2017 to expand into broad sections of South, West, and North Philadelphia, according to the city's still-fluid projections.
The full strategic plan is on the city's website at www.phila.gov/bikeshare - along with a link to the site where visitors can mark suggested bike-station locations on a map of the region.
Contact Bob Warner at 215-854-5885 or firstname.lastname@example.org.