Citi Bike may make for a nice ride on a beautiful day, but the bike-share program is also becoming a feature of the city's transportation network.

A study this week from NYU's Rudin Center for Transportation Policy and Management says the density of Citi Bike docks and their closeness to subway stations have made the blue bicycle an attractive transit alternative for completing "last mile" of a trip.

"You get off the subway and the Citi Bike is right there, that's going to make you more likely to hop on a bike and use it for a short trip," said the report's co-author, Lily Gordon-Koven.

There are nearly 20 Citi Bike docks within a square mile and 2.1 of them for every subway station within the bike share system's footprint. About three-quarters of docks are within a five-minute walk of a subway stop, with most stations within a half-mile, according to the report.

The report also details how closeness to a subway stop affects the popularity of a Citi Bike dock. o. Citi Bike stations that see the most action, including taking out a bike or docking one, are outside major transportation hubs such as Union Square, Penn Station and Grand Central Terminal -- "places that are already hubs of all kinds of activity but especially transportation," Gordon-Koven said.

Outerborough community leaders and lawmakers are clamoring for Citi Bikes in their neighborhoods to ease the issues of traveling through the city's "hub and spoke" transit system.

Councilman Jimmy Van Bramer, who has lobbied for Citi Bike docks in western Queens, said bike share can make trips between Brooklyn and Queens easier.

"There are gaps in connectivity and I think Citi Bike could help fill those gaps," he said.