As a mayoral candidate, Bill de Blasio promised a citywide network of more than 20 “world-class” Bus Rapid Transit routes within four years. More than a year into his term, bus riders are still waiting. Now 17 City Council members are asking the administration to take bolder action on BRT and offering to help NYC DOT and the MTA bring the projects to fruition.

Today council members from all five boroughs aligned with the influential Progressive Caucus sent a letter to Transportation Commissioner Polly Trottenberg and MTA Chair Tom Prendergast [PDF] in anticipation of a council hearing on BRT this afternoon.

“The physical and demographic patterns of the city have changed and the transit system is not changing with it fast enough to ensure equal access,” reads the letter. “Building on the successes of the Select Bus Service program, full-featured BRT is a cost-effective, efficient way of making [the city] more equitable, just, and sustainable.”

The council members offered to meet with Trottenberg, Prendergast, and their staffs to discuss how they “can help bring a network of BRT routes to New York City.”

Studies from the Pratt Center and New York University show that huge swaths of New York City’s low- and moderate-income residents live beyond the reach of the subway, but struggle with the high cost of car ownership. Bus Rapid Transit would be a lifeline to these New Yorkers.

To build effective busways where transit riders don’t get bogged down in traffic, the city will have to claim space from general traffic lanes and parking lanes. Inevitably, some elected officials will fight against prioritizing transit on the street. Today’s letter is the counterpoint showing that many council members want City Hall to act boldly and improve bus service for their constituents. Will de Blasio listen to them?

The mayor did highlight BRT as a component of his affordable housing plan during his State of the City address last week, but it played second fiddle to the headline-grabbing initiative to subsidize ferries.

Once in office, the administration interpreted the 20 world-class BRT routes pledge to mean an additional 13 lines on top of the existing seven Select Bus Service routes. Even by that measure, the de Blasio administration needs to pick up the pace to hit its target.

The administration has cut the ribbon on just one SBS route, the M60 on 125th Street, and has a few more in the planning stages, including the M86, which doesn’t include any bus lanes. And so far, only one project in the works, on Woodhaven and Cross Bay Boulevards, is being designed to the high standard for Bus Rapid Transit that advocates and council members are seeking.

The Progressive Caucus letter was released as the City Council transportation committee began its hearing on the de Blasio Administration’s BRT plans. We’ll have full coverage of the hearing, which also includes a bill to shift more of the city’s fleet to car-share vehicles, later today.