The city's bike share program is expanding. 

Alta Bicycle Share is taking ownership of Citi Bike, and officials say the new firm will double the size of the current system and improve service. 

The bike share is expected to have 12,000 bikes and 700 stations citywide by 2017. The expansion will eventually bring bikes to the northern half of Brooklyn, from Park Slope through Bushwick and Bed-Stuy. 

Borough President Eric Adams, an avid Citi Bike rider himself, released a statement saying in part, "We cannot underestimate the impact that this initiative has had on multiple facets of our daily life, improving our environment and public health while providing New Yorkers an easy alternative to getting from Point A to Point B."