According to TechCrunch, Ford put a man in a car seat disguise
so that a Ford Transit could masquerade as a true self-driving vehicle in order to evaluate how passers-by, other drivers on the road and cyclists reacted to sharing the road with an autonomous vehicle. From the report: The trial, conducted with the Virginia Tech Transportation Institute, also made use of a light bar mounted on the top of the windshield to provide communication about what the car was doing, including yielding, driving autonomously or accelerating from a full stop. The Transit Connect van used for the trial would indicate its behavior using signals including a slow white pulse for yielding, a rapid blinking for accelerating from a stop, and staying solid if it's actively in self-driving mode. The bar is positioned roughly where a driver's eye line would be, to try to catch the attention of those around it who would look in its direction.