NEW YORK, Nov. 30 (Xinhua) -- U.S. bike-share operator Citi Bike will double its service area and more than triple its fleet of bicycles in New York City (NYC) over the next five years, after its new owner Lyft planned to pour 100 million U.S. dollars into the company.

The NYC government and the U.S. Department of Transportation (DOT) announced on Thursday the investment, after Lyft said it had finished the acquisition of the NYC-based mobility startup Motivate, Citi Bike's initial parent company.

The expansion program will increase the number of Citi bikes on the streets to 40,000, double its service area by 35 square miles (around 90.6 million square meters), as well as add 12 new valet stations and more pedal-assist bikes. Yet it remained undetermined as to where the new bikes will be placed.

"This expansion means tens of thousands more New Yorkers are going to have a fast and inexpensive way to get around their city," said NYC Mayor Bill de Blasio in a Thursday statement.

Citi Bike is currently the largest U.S. bike-share company with roughly 12,000 docked bikes, 750 stations and exclusive operating rights within its service areas, including its current reach of Manhattan, Brooklyn and Queens.

Such locations have raised widespread criticism that they cater to wealthy riders in downtown areas. NYC has been developing dockless bike-share systems with other private companies to cover the Staten Island and the Bronx, two boroughs beyond Citi Bike's coverage.

Lyft's acquisition of Motivate came a few months after Uber bought dockless bike-share service Jump, one of the private companies currently piloting dockless bike-share programs in NYC.

As cycling in NYC has been growing faster than any other mode of travel to get around the city, private firms have been calling on the city government to allow more players to compete for better solutions for the city's public transportation, which has been under stress due to aging infrastructure and frequent congestion.

"The city should work with all parties to ensure access to everyone who wants to ride a bike to get around their communities -- not one company which has long left outer borough New Yorkers stranded," Uber spokeswoman Alix Anfang said in a statement.

The DOT and Citi Bike will soon hold public meetings across the city to discuss future services in potential new neighborhoods, Citi Bike said on Thursday night on Twitter.