Excerpt:

Newly found video appears to show Tesla testing or calibrating their automatic emergency braking system prior to the official release of the refreshed Model S. With several recent stories involving alleged failures of the system, the video of the test session is of particular interest.

The video appears to have been shot while Tesla engineers were evaluating automatic braking systems on a runway at the Naval Air Station in Alameda, California. Tesla has long used the facility for testing as it is a mere 30 mile jaunt from the Fremont factory (you may recall the first sighting of the Model X test mule was also on a runway at Alameda).