What does it take to get progress in walkability and great urban spaces? According to Gil Penalosa, founder of 8-80 Cities, the primary issue is not money or the details of a particular engineering solution, but pure political will. If we want to see what that looks like, we don’t have to look very far for a woman who is making an enormous positive impact in terms of getting a city’s infrastructure ready for the 21st century.

Janette Sadik-Khan was appointed by Michael Bloomberg as the Commissioner for the Department of Transportation in New York in 2007. There are those who might say that New York is a great, world-class city that doesn’t need any improvement. Not Janette Sadik-Kahn. She has launched head-first into a sustained burst of activity focused on livability and green transportation that has seen hundreds of miles of new bike lanes installed, pedestrian safety officers recruited, widespread new neighborhood traffic calming measures instituted, the pedestrianization of Times Square (!) and the launch of the nation’s biggest shared-bike program, Citibike. It’s good reason why Business Insider rated her #8 in their series ’50 Women Who Are Changing The World”.

Sadik-Khan clearly recognizes that in the 21st century, you don’t stay top by staying the same. Even in a great city like New York, it is necessary to constantly seek to provide the best living experience possible, or risk seeing talent go elsewhere. In 2013, that means enhancing public spaces for people, and taking real steps to prioritize green, active transportation and livable public spaces instead of using your downtown as a thoroughfare for cars / open parking lot.

It wasn’t easy for Sadik-Khan. People were skeptical about the changes she was implementing. Newspaper columnists wrote scathing, screaming attacks on her plans. Residents sued her, and demanded that she be fired. The New York Observer compared Sadik-Khan’s policies to Trotskyism. Another writer accused her grandfather of being an Islamist Nazi-collaborator, and argued that Sadik-Khan was deliberately making it harder for people to drive cars in New York in revenge for the Allied victory in World War II (yes- really!) Perhaps more damaging was the New York Times openly hand-wringing about whether it was all too much too soon.

This brings us to Sadik-Khan’s statement “When you push the status quo, the status quo pushes back at you.” There will always be people who will say we need to go more slowly, or that the case has not been fully made, or “that’s not the way we do things around here”. But if you want to have a green, walkable, livable town then you have to do things, not just talk about doing things. That is going to upset some people but if you’re like Janette Sadik-Khan, you stay the course. People everywhere are nervous about change, and it is often only years after the change has happened that they see the benefits. For example, even erstwhile critics of the bike lanes Sadik-Khan installed now find reason to praise them.

That’s what you get with Janette Sadik-Khan has brought vision, courage and leadership to New York. Now who’s going to be Princeton’s Janette?