Traffic4cast is an interdisciplinary competition on traffic prediction using machine learning, hosted by IARAI. Traffic4cast 2019 dataset includes industrial-scale real-world traffic data with over 100 billion points, provided by HERE Technologies. The dataset is derived from GPS positions of a large fleet of probe vehicles. Traffic data is sampled on 100m x 100m squares every 5 minutes throughout a year in 3 big cities: Berlin, Istanbul, and Moscow. The data is presented as a movie with traffic volume, speed, and direction encoded as RGB color channels. The goal of the competition is to predict the next 15 minutes of traffic in entire cities. The competition results were presented at the largest international machine learning conference NeurIPS 2019.