It seems like the radar/camera system Toyota uses for its Pre Collision System has the same weaknesses as Tesla's sensor suite but the list of exceptions in the Toyota manual is pretty brutally honest about the issues. Just for pedestrians it warns: Some pedestrians such as the following may not be detected by the radar sensor and camera sensor, preventing the system from operating properly:

• Pedestrians shorter than approximately 3.2 ft. (1 m) or taller than approx- imately 6.5 ft. (2 m)

• Pedestrians wearing oversized clothing (a rain coat, long skirt, etc.), mak- ing their silhouette obscure

• Pedestrians who are carrying large baggage, holding an umbrella, etc., hiding part of their body

• Pedestrians who are bending forward or squatting

• Pedestrians who are pushing a stroller, wheelchair, bicycle or other vehi- cle

• Groups of pedestrians which are close together

• Pedestrians who are wearing white and look extremely bright

• Pedestrians in the dark, such as at night or while in a tunnel

• Pedestrians whose clothing appears to be nearly the same color or brightness as their surroundings

• Pedestrians near walls, fences, guardrails, or large objects

• Pedestrians who are on a metal object (manhole cover, steel plate, etc.) on the road

• Pedestrians who are walking fast

• Pedestrians who are changing speed abruptly

• Pedestrians running out from behind a vehicle or a large object

• Pedestrians who are extremely close to the side of the vehicle (outside rear view mirror, etc.)

I'm trying to figure out whether there are actually a meaningful fraction of pedestrians who would be detected...

I imagine that list was drafted with the direction of the legal department and they wanted to exhaustive list that might very well exclude basically all pedestrians. They don't really expect many people to read it unless they find themselves in court, when it will be too late.

It still somewhat baffles me that these systems are trying to identify certain classes of object to avoid colliding with, rather than simply avoiding hitting anything solid over a certain size. Do I care whether the thing in front of me is a hatchback or a group of pedestrians? No! I just want the car not to hit it!

Huh, most of these I can understand with my layman's understanding of the sensors involved, but why would it miss the pedestrians who are on a metal manhole cover?

Not a Toyota engineer familiar with the problem, but my guess is a metal object produces a radar reflection significantly different from a pedestrian.

Why be so defensive of Tesla?

This isn’t fluffing up phone features, it’s presenting a system in such a way that key, known deficiencies that maim or kill are buried.

The people impacted by this trusted the system based on manufacturer claims, which unfortunately were and remain horseshit.

Isn't it designed and marketed to be trusted?

It's not companies like Tesla. As far as I can tell, it's just Tesla.