Highway barriers are different problem. RADAR, and I think ultra sound, has very poor angular resolution. So it’s very hard to distinguish between and object di

Highway barriers are different problem. RADAR, and I think ultra sound, has very poor angular resolution. So it’s very hard to distinguish between and object directly in front of you, from one just off do the side. As a result cars ignore RADAR data about stationary objects when the car is moving at speed. The assumption being those stationary objects are things like highway barriers to side of the car. You don’t want the break slamming on just because your driving parallel to the highway barrier. Consequence is that cars ignore stationary objects like highway barriers, when moving at speed. So if you’re heading straight at it, the car won’t slow down. But then the assumption is that the human really ought to notice they’re driving at a wall.