This document provides a profile of Janette Sadik-Khan, the commissioner of the New York City Department of Transportation. As commissioner, she has overseen many ambitious changes to New York City's transportation infrastructure, closing streets to cars and expanding bike lanes and pedestrian plazas. She uses data to justify her plans and convince skeptics. Some see her as a visionary updating the city, while others see her as disruptive. She works quickly to implement "pilot projects" and circumvent community approval processes to accelerate changes.