On Sunday, Select Bus Service launched on a route that stretches from 125th Street in Harlem to LaGuardia Airport. Public officials marked the occasion — the first SBS route to debut during the de Blasio era — at a Harlem press conference today. With off-board fare collection and dedicated bus lanes (on part of the route), the upgrades will speed cross-town trips for 33,000 bus riders daily, on both the M60 SBS route and local routes that will benefit from the bus lanes only.

Not that long ago, it seemed like SBS on 125th Street might never happen. The bus lanes were originally planned to extend between Second and Morningside Avenues, but after State Senator Bill Perkins led objections to the planning process, the plan was scaled back, calling for bus lanes between Second Avenue and Lenox. The entire project appeared dead soon after, then was revived in October after closed-door meetings with Perkins and other erstwhile opponents.

At today’s press conference, elected officials made the case for extending the bus lanes west to Morningside.

“While it’s a fabulous day for East Harlem, it’s a slightly less wonderful day for Central and West Harlem, because a key feature of this route, which is the bus-only lane you see right here, stops — comes to an abrupt halt — at Lenox Avenue,” said Council Member Mark Levine. “That’s simply not fair to residents in the western part of this wonderful street.”

Levine, whose call for extending the bus lane was echoed by State Senator Adriano Espaillat, said he hoped that it could be implemented as soon as this fall.

City Council Speaker Melissa Mark-Viverito thinks success on the initial segment will lead to westward expansion. “Once people start using this and really seeing the benefits, you’re going to start getting the support of people asking and clamoring for more,” she said. “Some of us, we thought this wouldn’t move forward.”

“DOT had to navigate some very choppy political waters in installing this,” Levine said as Mark-Viverito shared a smile with Transportation Commissioner Polly Trottenberg. “They were persistent, and I want to commend them for that.”

A few people were noticeably absent from today’s press conference, including Perkins and Council Member Inez Dickens, who both represent the area where today’s event was held and were part of the opposition that almost killed the project.

Also missing: Mayor Bill de Blasio, who has promised to bring the total number of SBS lines up to 20 within four years — a big increase over the initial six routes launched since 2008 under Mayor Michael Bloomberg. As mayor, Bloomberg attended the launch of each SBS route.

The twelve SBS stops on 125th Street (six in each direction) include wayfinding signage and Bus Time arrival information, which will help crosstown riders determine whether to purchase a ticket for the M60 SBS at a fare machine on the sidewalk, or wait to swipe their MetroCards on board a local bus. The signs cost approximately $30,000 each. The project costs a total $3.7 million, split between federal, state, and city funds.

So far, 125th Street does not include curb extensions or bus bulbs, but DOT Director of Transit Development Eric Beaton said the agency is in discussions with locals about where those types of upgrades could be installed.

The plan includes new left-turn restrictions from 125th to Fifth and Lexington Avenues, as well as some measures to address double parking. DOT adjusted parking regulations in advance of the SBS launch — adding rush hour loading zones on 125th and adding overnight parking spaces on 124th and 126th. But the agency did not introduce pricing reforms that it has used to manage demand and prevent double-parking on other commercial streets.

Another deterrent to double-parked drivers: The bus lanes will be camera-enforced to keep them clear. State legislation allowing bus lane cameras restricts them to six routes. Unless Albany changes the law, that would leave the city’s next SBS route (and the existing Webster Avenue route in the Bronx) without camera-enforced lanes. “The city’s going to need expanded authority in order to enforce our Select Bus Service lanes,” Trottenberg said. “That is also on our to-do list up in Albany.”

Going without cameras might not be a big problem for SBS on Woodhaven Boulevard, where DOT and the MTA recently began the project planning process. “We’re looking at that as sort of the closest thing to full BRT in the city,” Trottenberg said when asked about physically-separated bus lanes. She estimated the total cost of that line at approximately $100 million, compared to the $3.7 million spent on the M60.

The mayor’s budget includes $49 million in DOT capital funds for Select Bus Service expansion. Not all of that is going to Woodhaven Boulevard. Trottenberg, who has said the de Blasio administration will implement 13 more SBS lines by the end of the mayor’s four-year term, hinted at another SBS project on the way: “A couple weeks from now,” she said, “we’re going to start some of our outreach with the Flushing-Jamaica line.”