Étienne Tremblay
Hi, I'm Étienne! I am responsible for developing machine learning solutions to rider problems, and turning them into features that help Transit users in their journeys. Before working at Transit, I was building databases and analysis tools for the aerospace industry. I was also been involved in the mobility professorship at Polytechnique Montréal. I hold a B. Eng. in Aerospace from Polytechnique Montréal.
Session
In the twisting vaults of a subway, metro, or U-Bahn, there’s often no reliable cell service, wifi, or GPS. Which means riders had no good way of keeping track of their stops or ETA when underground.
After collecting extensive ground truth data, we trained a motion classifier using the phone's accelerometer to identify a moving train. This prediction is fed into a location model that combines it with the train schedule to estimate a location, even when GPS fails. We cover our unique data pipeline, feature engineering, and the optimization for high-scale, offline edge deployment to millions of users.