Let me begin by saying clearly. I DO NOT CARE HOW WELL IT WORKS IN INDIVIDUAL CARS. I'm sure it works pretty well. Will autobrake someday be triggered inappropriately? Of course. Do people brake for squirrels? Yes. Potentially lethal and a big deal for anyone directly affected, but not a reason not to have brakes or cars or autobrake as long as autobrake isn't being triggered inappropriately every few blocks. I could see it as an argument against squirrels, but that fluffy tail is way too effective for their side so I'll just leave that one alone.
But as soon as I found out about radar in cars, I really had one question and only one question: what happens when a lot of cars, say even most of the cars, have radar systems running all the time to the front and to the sides (we'll ignore the backing up one on the premise it's comparatively rare on the freeway) on a 6 lane highway with cars separated by a few car lengths and moving at an average speed above 50 mph? Is there an interference problem? Does it degrade performance of the sensing systems? Are there health consequences? R. is dismissive of this as any kind of problem, but we seem headed for this world kinda fast. (Har de har har) And I'm pretty sure that no one has ever tested radar systems in this kind of environment.
Please prove me wrong. With sourcing.
R. pointed out last night that to get the Top Safety Pick Plus rating from IIHS, a car has to have some kind of sensing system. I noted that the time frame from "important safety feature is available at all" to "important safety feature is mandatory" is way shorter than we usually realize -- on the order of a decade. Which for some people is forever, obvs, but not actually that long.
We will all apparently love it when we have it.
Component cost is high but falling.
"Engineers have done their part by ditching the expensive compound semiconductors in their radar sets in favor of the old standby, silicon—but a special form of silicon that's been speeded up."
If there really is a problem with active radar systems operating in close proximity at high speeds, one possible solution is passive radar systems (which already exist). If your IR vision system is a problem because everyone else has active goggles on, too, you can solve that by turning off your IR light and using a shared light. Presumably the same could work for cars, too. I'm in no way suggesting the shared radar source would come with control -- it wouldn't have to. It would just have to be in a known location, emitting at known frequencies, angles, etc. so the reflections could be interpreted correctly by the vehicles using it. I think these are all solvable problems, but just because there is a solution doesn't mean you don't have to work to implement it. (Contrary to the way that mathematicians in jokes think about things. "Go down to the basement. From there, it is a solved problem.")
More radar gives more options:
Will radar systems for crash avoidance trigger another car's radar detector (designed to detect police speed surveillance)?
Not in this test, anyway.
Car radar could make the roads safer for cycling:
These people offer retrofitting for warning, not to autobrake or anything like that:
Hey, look we have patents! And details.
In the EU
Things never develop as fast as you want them to and, depressingly, managing frequency really is an issue.