The Lane Changing Capabilities doesn’t appear to react to brake lights or turn signals, it can’t anticipate what other drivers will do, it has a tendency to cut off other drivers when making lane changes, according to CR’s tests.
After changing lanes in heavy traffic, the Model 3 “often immediately applies the brakes to create space behind the follow car—this can be a rude surprise to the vehicle you cut off,”
The rear cameras didn’t seem able to see very far behind the vehicle. Autopilot has forward-facing radar to help detect vehicles ahead of the car and measure their speed, but it lacks rear-facing radar that would give the car advance warning of vehicles approaching quickly from the rear. The result: CR found that the Model 3 tended to cut off cars that were approaching rapidly from behind.