Back when I worked on self driving cars we called it the cliff problem. It&#x27;s pretty straightforward to spot things that are in your way (trees, cones, broken down car) using LIDAR. It&#x27;s really hard to notice when a road abruptly ends. From the perspective of the cars&#x27; LIDAR a roll over and a sheer cliff look pretty similar. Either way you just won&#x27;t hit any targets at all with the laser beam. There was a silly obstacle on many self driving car courses that basically had the car drive up and over a relatively steep bump. At the crest of the hill the cliff detection would usually trigger and a lot of cars would just pause there, the roll over looked like a sheer cliff when the car was at a 15 degree up angle.<p>I assume we can make it work with computer vision for much the same reason humans don&#x27;t routinely (though sometimes) drive off cliffs.