Program will bring 750 bikes at 75 stations around town.

Portland’s planned bike-sharing system could bring 750 bikes available for short-term use, to be picked up at 75 different stations around town.

The Portland City Council expects to authorize a five-year contract on Wednesday with Portland-based Alta Bike Share to launch and operate the local bike-share program, pegged to cost $4.6 million to launch.

Portland is getting $2 million in federal funds to create the program, and will use up to $1.8 million of that money to reimburse Alta’s installation costs. The city’s contribution for the project, according to the proposed ordinance, is $1,820,000.

Bike share systems enable people to use a bike for short hops around the city instead of walking or using transit or automobiles. Such systems have proven successful at cities around the world.

The city hopes the service will result in 500,000 trips during the first year of service.