The latest version of Tesla’s vehicle software enables Autopilot to automatically stop at stop signs and traffic lights. Currently, Autopilot stops at all traffic lights, including green lights. To continue through a green light, the user has to press on the accelerator or pull the stalk next to the steering wheel. Every time a user does this, they label a traffic light as green. (Elon Musk confirmed this on Tesla’s Q1 2020 earnings call.) In the machine learning world, this is known as weak supervision.

Weak supervision can also be applied to free space: space without obstacles in it. People typically drive through space where there are no obstacles. So, when a person drives somewhere, they label it as free space. Conversely, when a person brakes unexpectedly, that action could potentially be used to label an area as not free space.

Tesla's competitive advantage isn't just that it has a fleet of over 800,000 vehicles. It also has a workforce of over 800,000 human labellers.