Tesla has extended its Austin Robotaxi service from 10pm to 11pm, and Elon Musk says the reason it cannot go later is that the cars have trouble seeing pets at night. In a post, he described the challenge as 'grey kittens on grey tarmac in the dark.' That is a classic low-light, low-contrast scenario for cameras, which rely on reflected light and visual contrast to detect objects.
Cameras are passive sensors; lidar and radar are active. Lidar fires laser pulses and measures their return time, building a 3D picture that works in darkness regardless of color. Radar does similar with radio waves and adds speed information. Tesla removed radar from its cars in 2021 and ultrasonic sensors in 2022, and has never shipped lidar. Musk has previously called lidar a 'fool's errand' and a 'seductive local maximum.' Waymo, by contrast, equips its vehicles with cameras, lidar, and radar, and runs roughly 4,000 driverless cars around the clock.
Electrek notes that the extra hour still leaves the service closing earlier than it did on day one, when it ran until midnight. The outlet also points out that customer Teslas with Full Self-Driving use the same camera-only system at any hour, with no curfew. No sensor suite is perfect — a Waymo once ran over a cat in San Francisco — but Tesla is the only operator whose CEO says the car cannot see the animal in the first place.