'Simply' is an overstatement, though. The technology needed to achieve this involves tons of software, fed by data from special high-resolution laser scanners embedded in the front and side of the car that can see the distances between objects. This is a new kind of sensor--cars are already being studded with cameras, radars, LiDAR, and more--whose precision makes this safety feature possible.
The experiment works at speeds up to 15 miles per hour. It took me a few tries to un-train myself from avoiding the obstacles. Then it became a game for me to try to hit things, except the car always won. Benjamin Gutjahr of BMW said if they added other kinds of sensors, they could add pedestrian protection.
BMW says this technology could be ready in about five years. In the meantime, automakers will continue adding other elements of autonomous driving to cars, bit by bit, as they have been for years. I expect by the time this feature comes online, we'll barely notice it anymore. But it'll still be a great safeguard against the unexpected or unseen.