Zhenhui (Jessie) Li --- Large-scale mobility data can be collected from mobile phones, car navigation systems, road surveillance cameras, and loop sensors. Turning such raw data into knowledge can provide insights about our city and empower the city to be more intelligent. In this talk, I would like to share new data mining and machine learning technologies to addressing challenges in travel demand prediction, travel time estimation, and intelligent traffic signal control. In addition, I would like to share an opportunity of City Brain project, which I will soon start working on from summer 2018. This project will be in collaboration with traffic police department of Hangzhou, China. We will be exploring AI-empowered data-driven traffic signal control system.