NYC DOT’s top planner and a key figure in the ongoing evolution of New York City streets is moving on. Deputy Commissioner for Transportation Planning and Management Ryan Russo will be heading to Oakland as the city’s first-ever DOT chief.

Wednesday was Russo’s last day at NYC DOT after a 14-year tenure during which he introduced and implemented new street design concepts, including the city’s first modern, on-street protected bike lanes. DOT is now accepting applications to fill some very big shoes.

The DOT of 2017 is much more nimble and capable of executing projects that prioritize walking, biking, and transit than the agency of 12 years ago, and Russo is a big reason why. He knows the intricacies of both the technical and political aspects of street transformation better than anyone. And while Streetsblog didn’t always see eye-to-eye with his assessments, he leaves behind a remarkable and wide-ranging legacy.

Russo’s career at DOT spanned three commissioners. He began as Downtown Brooklyn Transportation Coordinator under Iris Weinshall in 2003. Among the groundbreaking projects he spearheaded in that time were the proto-protected bike lane on Tillary Street by the Brooklyn Bridge and the design of the Sands Street bikeway.

Starting in 2006, Russo led DOT’s bicycle and pedestrian program through a period of unprecedented growth for biking, walking, and public space improvements. He played a leading role in DOT’s major street redesigns under Transportation Commissioner Janette Sadik-Khan, including but not limited to the transformation of Broadway and its string of plazas from Columbus Circle to Union Square, as well as protected bike lanes on Ninth Avenue, Kent Avenue, Prospect Park West, and elsewhere.

An indispensable contribution during this time was the development of DOT’s low-cost street design toolkit. These are the elements New Yorkers are now used to seeing everywhere DOT redesigns a street — paint, planters, epoxy-and-gravel surfacing, floating concrete islands. Thanks to this in-house menu of materials, the city can go from design to implementation in a matter of months, instead of waiting years (or even decades) for the Department of Design and Construction to finish a job.

In his role as the lead planner under Transportation Commissioner Polly Trottenberg, Russo has overseen DOT’s citywide Vision Zero strategy and implementation, working to expand the scope and extent of safety improvements throughout the five boroughs. NYC has bucked national trends by continuing to reduce traffic deaths each year, as streets like Queens Boulevard, the city’s most notorious motorway, get safer accommodations for walking and biking.

Trottenberg said Russo will be sorely missed. “I look around the city, and I see he’s made our streets so much safer, so much more livable,” she said. “He’s been transformative, and I think his work is going to live on here for generations to come.”

Here he is walking through the Queens Boulevard redesign, in the video that won our readers’ choice award for the best Streetfilm of 2016:

David Meyer contributed reporting for this story.