It&#x27;s not that hard.  You use LIDAR to generate a topographic map of the terrain ahead. We were doing that 10 years ago for the DARPA Grand Challenge. For off-road driving, this is essential.  A high-mounted LIDAR lets you do this. It&#x27;s not just about sensing obstacles.  You profile the height of the terrain ahead, cell by cell.<p>There&#x27;s a range limit on terrain profiling, though, imposed by parallax and the height of the scanner above the road. The higher, the better, of course.  For a scanner 2m above the road, you can get good profiles out to 20m or so.  This is enough to let you drive about 35- 40mph, which is enough for most heavy snow situations.