Almost half of the rides taken on Citi Bike last for under 10 minutes, and riders use the service as a way to get to and from major transit hubs, according to a new study of the bike share system by NYU's Rudin Center for Transportation Policy and Management.

The Rudin Center report shows that most of the trips on the service are taken in Manhattan, which isn't surprising given that 366 of the 614 total stations are in the borough. In September 2016, 83% of trips began or ended in the Manhattan, and the island was also home to all 10 of the 10 most frequently used stations in the system.

Even with the use of the system centered in Manhattan, 85% of the rides taken in September were by annual members (presumably mostly residents), with 24-hour and 7-day pass riders only accounting for 15% of the rides. Of those rides, 98 percent of them lasted for under 45 minutes, and 48 percent of them lasted for under 10 minutes, which according to the study's authors means that "riders are using Citi Bike to make short trips around their neighborhoods or as last-mile connections to transit for longer trips."

Three major Manhattan transit hubs are especially flush with Citi Bike options, according to the study. There are 1,092 bikes within half a mile of Penn Station, 1,132 within half a mile of Grand Central and 1,125 within half a mile of the Port Authority.

And while Manhattan south of Central Park is well-served by the layout of the Citi Bike system at the moment, the Rudin Center study suggests that there's "potential" for the system to work in the less dense outer borough areas that are somewhat underserved by Citi Bike. While admitting that the population density in Brooklyn and Queens wouldn't support the kinds of ridership numbers in Manhattan, the study's authors suggest that the usage patterns in the system prove Citi Bike can serve both act as a backup transit option for neighborhoods served by just one transit line.

"Citi Bike can continue to provide short trips, connecting neighborhoods that are currently underserved by more traditional transit methods, and offering a last mile option in areas further away from transit stops," the study argues.

However, due to the potential for less frequent usage, the report suggests that any expansion would "require new sources of private and public funding support for both capital and operations." This issue came up during a City Council hearing on Citi Bike's expansion in November last year. Jay Walder, the CEO of Citi Bike owner Motivate, told the council that he didn't think Citi Bike could expand "without some degree of public support." Council Member Ydanis Rodriguez suggested that he and other council members were ready to help expand the system with public money, but DOT commissioner Polly Trottenberg warned the Council that a higher level of public money and its attendant higher level of oversight would make things "challenging."