With the Democratic primary a week away, StreetsPAC, NYC’s first-ever livable streets political action committee, today endorsed Bill de Blasio to succeed Michael Bloomberg as mayor.

The group cited de Blasio’s commitment to the expansion of the city’s bike lane network and bike-share, improving bus service outside Manhattan, and dramatically reducing traffic injuries and deaths.

“Bill understands how important biking, walking and transit are to the future of New York City,” said StreetsPAC founding board member Steve Vaccaro, via a press release. “He knows that safe streets are no accident and he has promised to wage an aggressive campaign to reduce injuries and fatalities caused by motor-vehicle crashes. Bill is committed to working with communities to expand the benefits of better bus service, pedestrian-safety measures and improved and connected biking across all five boroughs as mayor. StreetsPAC supports his progressive, equitable vision.”

StreetsPAC distributed questionnaires to mayoral candidates, and conducted interviews with de Blasio and Christine Quinn. The group told Dana Rubinstein at Capital New York that Bill Thompson, who unveiled his auto-centric transportation plans in August, returned the StreetsPAC questionnaire, but “didn’t show up” for an interview. Republican frontrunners Joe Lhota and John Catsimatidis did not return the questionnaire.

“The fact that [Quinn and de Blasio] were willing to meet with us shortly before the election and Thompson wasn’t told us that Thompson wasn’t taking us seriously, and wasn’t taking transportation as seriously as a campaign issue as de Blasio and Quinn were,” said Eric McClure, another founding board member, to CapNY.

Ultimately, StreetsPAC chose de Blasio over Quinn based on the scope of his transpo platform, which includes a pledge to adopt a “Vision Zero” approach to street safety.

“[H]e of all the candidates has the most quantifiable, measurable goals for how he is going to increase the safety and [livability] of city streets,” said founding board member Doug Gordon.

Said de Blasio, in a statement that accompanied the StreetsPAC announcement: “This is part of the bedrock of making New York City more sustainable, more livable and safer for every family. We’re going to make sure that neighborhoods that have waited for change on their streets have it, and we’ll make sure New York City remains an innovator of ways to make biking, walking and public transit safer and more accessible to every single New Yorker.”