The problem isn't that they're effective. It's that they're a regulatory solution to the complaints that the same demographics had 20yr ago (it's too easy to back a big fashionable in the 00s SUV over a kid) and as a result of it now all cars have crap rear visibility because there's no reason to be good when you have the camera.
The primary factor that correlates with reverse cameras reducing backup accidents is age - people over 70 have higher backup accidents rates without cameras/sensors. FTA:
> When averaged between the 2 automakers, effects were significantly larger for drivers 70 and older (38% reduction) than for drivers younger than 70 (1% increase); effects were significant for older but not younger drivers.
A big SUV is probably an exacerbating factor, though.
Also, for any kind of car, rear cameras and sensors decrease impacts while parallel parking. I see far fewer damaged bumpers on newer cars these days.
Visibility has gotten worse in many vehicles as a crash safety thing. Rear visibility is so blocked because the "beltline" of cars has moved up as crash standards get more stringent. A car that has a small rear window and high 'beltline' will do better in a crash.
TBH, I'm hoping we have front-view cameras that maybe kick in at under 20kph or something.
Front visibility is famously poor on SUVs and trucks, and even aside from pedestrians, I suspect there are a lot of small but very expensive bumper taps because you mis-judged the distance to the crap at the back wall of your garage.
