A long-discussed bike-share program in Portland took another incremental step forward on Thursday when city officials asked vendors to help explore options and potential costs of launching a citywide system.

Bike-share programs offer communal bicycles that are available to the public or to program members for short-term use. In most major programs, users pick up and drop off the bicycles at specific “bike stations” for a fee.

The programs have surged in popularity in many large cities such as Washington, D.C., and Boston and are hailed as a way to reduce vehicle congestion and related pollution while encouraging healthy lifestyles. Portland officials began planning for a bike-share system in 2013 with help from a roughly $25,000 grant from the U.S. Environmental Protection Agency.

On Thursday, the city announced a “request for information” asking for venders to help “evaluate options for business and organizational bike share models” and compile cost estimates for the program. That information is intended to help city planning staff before Portland moves forward with the next step, which would likely be a formal request for proposals.

Vendors will not be paid for providing the information and the process will not end with a vendor being selected to run the program.

“As we worked on this issue and spoke to companies and other cities pursuing bike sharing, two things became clear,” Jeff Levine, Portland’s director of planning and urban development, said in a statement. “One is that the city is not going to be able to fund or implement a system on its own, and will need regional partners like the Bicycle Coalition of Maine and private companies to bring a system to town. The second is that many successful communities have brought on an industry partner in a similar fashion, early on in their program development, to help develop a business plan and funding strategy.”

Portland already has one bike-share station – operated by the company Zagster for Northern New England Passenger Rail Authority – but it is located at the Portland Transportation Center and only allows rentals for the day. The program envisioned by Portland officials and bicycling advocacy groups would be citywide with multiple stations allowing shorter-term use of the bikes.

South Portland is also exploring a separate bike-share program.

Boston’s bike-share system, known as New Balance Hubway, features more than 1,300 bicycles at 140 bike stations in Boston, Cambridge, Brookline and Somerville. The system reported more than 1 million total trips between its launch in July 2011 and July 2013.