On a related note, Chick-fil-A using Deep Learning models for object detection with MXNet to track how long fries have been waiting: https://www.youtube.com/watch?v=3Uuq_cX8b1M
The project will be financed by the Boring company, not by the city. The Heathrow express in London work on a similar concept, it takes 15 min to go to Heathrow compared to 1h with the tube, and they charge ~10 times the price of a regular tube ticket.