When you’re in Manhattan and certain parts of Brooklyn and Queens, the blue bicycle is everywhere.

Citi Bike has, in many ways, become part of NYC’s transportation landscape. In the two years since Motivate, a company led by former MTA chief Jay Walder, took over Citi Bike, the program has become a success, growing to 10,000 bicycles and 14 million rides in 2016.

Now, the program is at a crossroads. It’s in its final year of a planned expansion, and its success has led advocates to hope for further growth. After all, there are no Citi Bikes in the Bronx or Staten Island, and many parts of Queens and Brooklyn remain unserved, too.

But it’s not that simple. Motivate executives say they can’t expand more without public money, noting that operations in other cities, like Boston, are entirely publicly funded. Bikes in areas that are less dense or have lower incomes won’t bring in enough revenue, they say. And, they add, there aren’t enough new private funding options.

For now, we have no way to know. Motivate estimates capital costs at about $6,000 per new bicycle, but won’t publicly detail its operating expenses. That means we don’t know how much the program costs. And we also don’t know enough about Motivate’s revenue or profits. And finally, Motivate hasn’t tested Citi Bike in the Bronx or Staten Island, so it’s unclear whether it can succeed.

Motivate wants taxpayer money to fund Citi Bike’s expansion. The company has to do more to show taxpayers why. The company has to detail exactly how much the program costs, and why private funds won’t cover it. Does it really cost $6,000 per new bicycle? What are the operating costs? And are their profit margins that thin? Meanwhile, Motivate should find ways to bring in new private investment, and should consider a pilot program in a neighborhood in the Bronx or in a transit desert of Queens or Brooklyn, to determine the demand and potential for expansion.

There are going to be plenty of demands on this year’s NYC budget. Without more information, bike-sharing doesn’t ride to the front of that list.