I was driving east on [XXX] in Bourne MA using the Tesla adaptive cruise control system called ‘Autopilot’ in very light traffic conditions. The sun was low on in the sky (behind and to the right). The system automatically engaged the brakes while crossing the bridge without obvious reason, decreasing the car speed about 10 MPH in less than a second before I overrode by pressing the accelerator. I believe the car vision system mistook a shadow cast by the vertical girders on the bridge onto the road as an obstacle. The sudden deceleration was a hazard to those behind that had to brake, but there was no collision or loss of control. The manufacturer seems acknowledge and accept that the defect exists, but has not been able to resolve the problem. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)