A Brooklyn Council member unveiled legislation on Thursday that would require the city build 100 miles of protected bike lanes a year, doubling the number that the city is already required to build under the Streets Plan — an escalation that comes after the city failed to reach the existing law’s even lower first-year benchmark.

The bill by Council Member Rita Joseph (D-Flatbush) emphasizes the need for more protected bike lanes to make streets safer and “increase cycling.” But it will present a huge challenge for the Department of Transportation, which failed to hit its 30 mile requirement in 2022 — a requirement that rises to 50 miles this year. Joseph’s bill, co-sponsored by Council Member Lincoln Restler (D–Williamsburg), would raise that to 100 starting this year through the end of 2028.

Joseph was unavailable to comment on Thursday, and Restler deferred to her to comment, as she is the lead on the legislation.

DOT sources told Streetsblog last year — when the DOT only built 26.3 miles of protected lanes — that the agency would not likely even be able to meet the higher, 50-mile benchmark this year.

And that comes after the DOT did even worse for its bus lane requirement of 20 miles, setting up just 4.4 miles of protected transit paths last year. That benchmark rises to 30 miles each coming year.

DOT has suffered staffing shortages under the Adams administration, and Transportation honchos have said from the beginning of the Streets Plan proposal in 2019 that they would need a lot more money, people, and resources to meet the targets.

Advocates have long wanted the city to build out a fully protected bike network, but some also added the city should first focus how to keep bike lanes clear of motor vehicles.

“We appreciate the Council members’ appetite for a comprehensive bike network, but maybe we should table this one until the Council and mayor work out a budget that gets us 50 [miles] per year, and we see some Adams administration commitment to addressing the chronic blockage of ‘protected’ bike lanes by cars and trucks,” said Jon Orcutt of Bike New York.

It could also be difficult to notch a larger number of projects because DOT has to notify community boards 90 days before installing or removing a bike lane, and then wait an additional 45 days after a board hearing to do the work — leaving narrow windows in each year’s warmer weather painting seasons.

“Obviously, I’d love to see the city build 100 miles of bike lanes a year,” said John Tomac of Bike South Brooklyn. “I’d be surprised if they could pull it off right now. That’s not necessarily a knock on DOT, but there are some real obstacles.”

Joseph’s 40th Council District south and east of Prospect Park could definitely use more dedicated lanes for cyclists. It ranks 35th for protected bike lane mileage out of the city’s 51 districts, with just a little over 1 percent of streets including the secure paths for cyclists, even though 61 percent of commuters bike, walk, or ride transit, according to MIT’s Spacial Equity database.

DOT spokesman Vin Barone didn’t say whether the agency would be capable of adding double the lane mileage a year, but the rep said they are reviewing the legislation.