No one has greater influence over the safety and design of New York City’s streets than its mayor. During Mike Bloomberg’s tenure, and especially in the six years since he wisely appointed Janette Sadik-Khan to run the Department of Transportation, New York’s streets have undergone a transformation, making the city a safer and more pleasant place. But much work remains to be done.

After careful consideration of the candidates’ records, position papers and public statements, review of their responses to our detailed questionnaire, and in-person interviews, we are endorsing Bill de Blasio for mayor in the New York City Democratic primary election. Mr. de Blasio’s pledge to change leadership in the NYPD and crack down on dangerous driving, his embrace of the “Vision Zero” program to eliminate preventable traffic deaths, and his commitment to expand the city’s bike-lane network and bike-share system were among the key factors in our decision.

“Of all the Mayoral candidates, Bill de Blasio has laid out the most progressive vision for continuing to make New York City’s streets safer and more accessible to everyone, regardless of mode of transportation,” said Steve Vaccaro, a StreetsPAC board member. “Bill’s commitment to reform the way the NYPD does traffic enforcement, his conviction that we can and should eliminate road deaths, and his belief that access to reliable transit is a fundamental equity issue make him the clear choice for livable-streets voters.”

StreetsPAC’s choice of Mr. de Blasio was not made without careful consideration of his chief rival in the primary race, City Council Speaker Christine Quinn. Clearly, Speaker Quinn takes transportation issues seriously. She has been generally supportive of initiatives like the expansion of the bike-lane network, pedestrian plazas, and neighborhood slow zones. She’s committed to making the streets safer and to improving transit. But Mr. de Blasio has laid out a more complete and compelling vision.

Beyond Ms. Quinn, Sal Albanese deserves special mention for elevating the discourse among the candidates on transportation issues, especially with his embrace of a smart fair-tolling plan that would ease congestion and raise revenue for the transit system. Other candidates, however, have failed to put forth any meaningful ideas. In many cases, their views on transportation appear firmly rooted in the last century. It was not difficult to eliminate them from consideration.

Mr. de Blasio, by contrast, has outlined a number of positions long urged by advocates for safe and complete streets. He has pledged to appoint a new police commissioner and prioritize enforcement of the most dangerous traffic violations – speeding and failure to yield – which are among the leading causes of crashes that kill or seriously injure pedestrians and cyclists, as well as other motorists. He has stated clearly that he believes the NYPD must crack down on reckless and distracted driving.

Mr. de Blasio’s embrace of Vision Zero also sets him apart from his competitors. Achieving Vision Zero – the goal of reducing fatalities on our streets to zero – would save hundreds of lives a year. Toward that end, Mr. de Blasio has pledged to quadruple the number of Neighborhood Slow Zones in New York City in four years, to expand NYPD crash investigations to include all crashes causing serious injury, and to push for home rule that would empower the city to deploy hundreds more speed-enforcement and red-light cameras.

In addition to making streets safer, Mr. de Blasio is committed to making them more accessible and equitable, especially in under-served outer-borough neighborhoods. He is committed to creating a world-class Bus Rapid Transit system, and to expanding the bike-lane network and bike-share program throughout the city. His goal of 6% bicycle mode share by 2020 would put New York on par with the most bike-friendly U.S. cities.

“Bill de Blasio clearly understands that a successful 21st century city is one that embraces safe and complete streets,” said StreetsPAC board member Joanna Oltman Smith. “It’s fundamental not only to quality of life, but to a vibrant and competitive economy. New York City has made great strides in transforming its streets and public spaces over the past decade, and we believe that Bill de Blasio is the best choice to keep us on that path.”