> Radar knows the speed of any object it sees, and is also simple, cheap, robust, and easy to build into a front bumper. But it also detects lots of things a ca

> Radar knows the speed of any object it sees, and is also simple, cheap, robust, and easy to build into a front bumper. But it also detects lots of things a car rolling down the highway needn't worry about, like overhead highway signs, loose hubcaps, or speed limit signs. So engineers make a choice, telling the car to ignore these things and keep its eyes on the other cars on the road: They program the system to focus on the stuff that's moving. So these car-mounted radar systems can't detect how large an object is or where it is in relation to the road? I don't get how they can be used at all then. That can't be true, right? Because if you can tell how large something is, then the hubcap is out. And if you can tell where something is in relation to the vehicle and/or road, then the signs are out. I mean, hell, the most maniacal situation of climbing a steep hill with clearance under a sign that you just can't see because the sign happens to be mounted just after the rise, which probably doesn't exist anywhere in the world, would be out by other factors, like knowing that you're going up a steep hill. So it really sounds like the only thing left is just not being able to tell how large something is, which sounds wild. > This unsettling compromise may be better than nothing People frequently find disappointment to be worse than nothing.